diff --git a/src/errors.h b/src/errors.h
index 0d53fa84c..6184037df 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -3411,16 +3411,14 @@ EXTERN char e_public_member_name_cannot_start_with_underscore_str[]
 	INIT(= N_("E1332: Public member name cannot start with underscore: %s"));
 EXTERN char e_cannot_access_private_member_str[]
 	INIT(= N_("E1333: Cannot access private member: %s"));
-EXTERN char e_object_member_not_found_str[]
-	INIT(= N_("E1334: Object member not found: %s"));
 EXTERN char e_member_is_not_writable_str[]
 	INIT(= N_("E1335: Member is not writable: %s"));
 #endif
 EXTERN char e_internal_error_shortmess_too_long[]
 	INIT(= "E1336: Internal error: shortmess too long");
 #ifdef FEAT_EVAL
-EXTERN char e_class_member_not_found_str[]
-	INIT(= N_("E1337: Class member not found: %s"));
+EXTERN char e_class_member_str_not_found_in_class_str[]
+	INIT(= N_("E1337: Class member \"%s\" not found in class \"%s\""));
 EXTERN char e_member_not_found_on_class_str_str[]
 	INIT(= N_("E1338: Member not found on class \"%s\": %s"));
 #endif
@@ -3488,7 +3486,6 @@ EXTERN char e_cannot_access_private_method_str[]
 	INIT(= N_("E1366: Cannot access private method: %s"));
 EXTERN char e_member_str_of_interface_str_has_different_access[]
 	INIT(= N_("E1367: Access level of member \"%s\" of interface \"%s\" is different"));
-
 EXTERN char e_static_cannot_be_followed_by_this[]
 	INIT(= N_("E1368: Static cannot be followed by \"this\" in a member name"));
 EXTERN char e_duplicate_member_str[]
@@ -3501,6 +3498,16 @@ EXTERN char e_abstract_method_in_concrete_class[]
 	INIT(= N_("E1372: Abstract method \"%s\" cannot be defined in a concrete class"));
 EXTERN char e_abstract_method_str_not_found[]
 	INIT(= N_("E1373: Abstract method \"%s\" is not implemented"));
+EXTERN char e_class_member_str_accessible_only_inside_class_str[]
+	INIT(= N_("E1374: Class member \"%s\" accessible only inside class \"%s\""));
+EXTERN char e_class_member_str_accessible_only_using_class_str[]
+	INIT(= N_("E1375: Class member \"%s\" accessible only using class \"%s\""));
+EXTERN char e_object_member_str_accessible_only_using_object_str[]
+	INIT(= N_("E1376: Object member \"%s\" accessible only using class \"%s\" object"));
+EXTERN char e_static_member_not_supported_in_interface[]
+	INIT(= N_("E1377: Static member is not supported in an interface"));
+EXTERN char e_method_str_of_class_str_has_different_access[]
+	INIT(= N_("E1378: Access level of method \"%s\" is different in class \"%s\""));
 EXTERN char e_cannot_mix_positional_and_non_positional_str[]
 	INIT(= N_("E1400: Cannot mix positional and non-positional arguments: %s"));
 EXTERN char e_fmt_arg_nr_unused_str[]
@@ -3521,4 +3528,4 @@ EXTERN char e_aptypes_is_null_nr_str[]
 	INIT(= "E1408: Internal error: ap_types or ap_types[idx] is NULL: %d: %s");
 EXTERN char e_interface_static_direct_access_str[]
 	INIT(= N_("E1409: Cannot directly access interface \"%s\" static member \"%s\""));
-// E1371 - E1399 unused
+// E1376 - E1399 unused
diff --git a/src/eval.c b/src/eval.c
index dd7b8d8f3..523546957 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1596,10 +1596,7 @@ get_lval(
 
 		if (lp->ll_valtype == NULL)
 		{
-		    if (v_type == VAR_OBJECT)
-			semsg(_(e_object_member_not_found_str), key);
-		    else
-			semsg(_(e_class_member_not_found_str), key);
+		    member_not_found_msg(cl, v_type, key, p - key);
 		    return NULL;
 		}
 	    }
diff --git a/src/proto/vim9class.pro b/src/proto/vim9class.pro
index a61c40f23..1448f1915 100644
--- a/src/proto/vim9class.pro
+++ b/src/proto/vim9class.pro
@@ -26,6 +26,8 @@ int set_ref_in_classes(int copyID);
 void object_created(object_T *obj);
 void object_cleared(object_T *obj);
 int object_free_nonref(int copyID);
+void method_not_found_msg(class_T *cl, vartype_T v_type, char_u *name, size_t len);
+void member_not_found_msg(class_T *cl, vartype_T v_type, char_u *name, size_t len);
 void f_instanceof(typval_T *argvars, typval_T *rettv);
 int class_instance_of(class_T *cl, class_T *other_cl);
 /* vim: set ft=c : */
diff --git a/src/structs.h b/src/structs.h
index 921409697..4a82c82e6 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1791,8 +1791,11 @@ struct ufunc_S
     def_status_T uf_def_status; // UF_NOT_COMPILED, UF_TO_BE_COMPILED, etc.
     int		uf_dfunc_idx;	// only valid if uf_def_status is UF_COMPILED
 
-    class_T	*uf_class;	// for object method and constructor; does not
-				// count for class_refcount
+    class_T	*uf_class;	// for class/object method and constructor;
+				// does not count for class_refcount.
+				// class of the object which is invoking this
+				// function.
+    class_T	*uf_defclass;	// class where this function is defined.
 
     garray_T	uf_args;	// arguments, including optional arguments
     garray_T	uf_def_args;	// default argument expressions
diff --git a/src/testdir/test_vim9_class.vim b/src/testdir/test_vim9_class.vim
index be4eb2eb8..1796f5f72 100644
--- a/src/testdir/test_vim9_class.vim
+++ b/src/testdir/test_vim9_class.vim
@@ -8,56 +8,56 @@ def Test_class_basic()
       class NotWorking
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1316:')
+  v9.CheckSourceFailure(lines, 'E1316:')
 
   lines =<< trim END
       vim9script
       class notWorking
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1314:')
+  v9.CheckSourceFailure(lines, 'E1314:')
 
   lines =<< trim END
       vim9script
       class Not@working
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1315:')
+  v9.CheckSourceFailure(lines, 'E1315:')
 
   lines =<< trim END
       vim9script
       abstract noclass Something
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E475:')
+  v9.CheckSourceFailure(lines, 'E475:')
 
   lines =<< trim END
       vim9script
       abstract classy Something
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E475:')
+  v9.CheckSourceFailure(lines, 'E475:')
 
   lines =<< trim END
       vim9script
       class Something
       endcl
   END
-  v9.CheckScriptFailure(lines, 'E1065:')
+  v9.CheckSourceFailure(lines, 'E1065:')
 
   lines =<< trim END
       vim9script
       class Something
       endclass school's out
   END
-  v9.CheckScriptFailure(lines, 'E488:')
+  v9.CheckSourceFailure(lines, 'E488:')
 
   lines =<< trim END
       vim9script
       class Something
       endclass | echo 'done'
   END
-  v9.CheckScriptFailure(lines, 'E488:')
+  v9.CheckSourceFailure(lines, 'E488:')
 
   lines =<< trim END
       vim9script
@@ -65,7 +65,7 @@ def Test_class_basic()
         this
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1317:')
+  v9.CheckSourceFailure(lines, 'E1317:')
 
   lines =<< trim END
       vim9script
@@ -73,7 +73,7 @@ def Test_class_basic()
         this.
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1317:')
+  v9.CheckSourceFailure(lines, 'E1317:')
 
   lines =<< trim END
       vim9script
@@ -81,7 +81,7 @@ def Test_class_basic()
         this .count
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1317:')
+  v9.CheckSourceFailure(lines, 'E1317:')
 
   lines =<< trim END
       vim9script
@@ -89,7 +89,7 @@ def Test_class_basic()
         this. count
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1317:')
+  v9.CheckSourceFailure(lines, 'E1317:')
 
   lines =<< trim END
       vim9script
@@ -98,7 +98,7 @@ def Test_class_basic()
         that.count
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1318: Not a valid command in a class: that.count')
+  v9.CheckSourceFailure(lines, 'E1318: Not a valid command in a class: that.count')
 
   lines =<< trim END
       vim9script
@@ -106,7 +106,7 @@ def Test_class_basic()
         this.count
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1022:')
+  v9.CheckSourceFailure(lines, 'E1022:')
 
   lines =<< trim END
       vim9script
@@ -117,7 +117,7 @@ def Test_class_basic()
       endclass
       var obj = Something.new()
   END
-  v9.CheckScriptFailure(lines, 'E1089:')
+  v9.CheckSourceFailure(lines, 'E1089:')
 
   lines =<< trim END
       vim9script
@@ -125,7 +125,7 @@ def Test_class_basic()
         this.count : number
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1059:')
+  v9.CheckSourceFailure(lines, 'E1059:')
 
   lines =<< trim END
       vim9script
@@ -133,7 +133,7 @@ def Test_class_basic()
         this.count:number
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1069:')
+  v9.CheckSourceFailure(lines, 'E1069:')
 
   # Test for unsupported comment specifier
   lines =<< trim END
@@ -143,7 +143,7 @@ def Test_class_basic()
       #{
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1170:')
+  v9.CheckSourceFailure(lines, 'E1170:')
 
   lines =<< trim END
       vim9script
@@ -171,7 +171,7 @@ def Test_class_basic()
       assert_equal('class<TextPosition>', typename(TextPosition))
       assert_equal('object<TextPosition>', typename(pos))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # When referencing object methods, space cannot be used after a "."
   lines =<< trim END
@@ -184,7 +184,7 @@ def Test_class_basic()
     var a = A.new()
     var v = a. Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1202:')
+  v9.CheckSourceFailure(lines, 'E1202:')
 
   # Using an object without specifying a method or a member variable
   lines =<< trim END
@@ -197,7 +197,7 @@ def Test_class_basic()
     var a = A.new()
     var v = a.
   END
-  v9.CheckScriptFailure(lines, 'E15:')
+  v9.CheckSourceFailure(lines, 'E15:')
 
   # Error when parsing the arguments of an object method.
   lines =<< trim END
@@ -209,7 +209,7 @@ def Test_class_basic()
     var a = A.new()
     var v = a.Foo(,)
   END
-  v9.CheckScriptFailure(lines, 'E15:')
+  v9.CheckSourceFailure(lines, 'E15:')
 
   lines =<< trim END
   vim9script
@@ -220,7 +220,7 @@ def Test_class_basic()
   endclass
   var a = A.new()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_class_defined_twice()
@@ -232,7 +232,7 @@ def Test_class_defined_twice()
       class There
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1041: Redefining script item: "There"')
+  v9.CheckSourceFailure(lines, 'E1041: Redefining script item: "There"')
 
   # one class, reload same script twice is OK
   lines =<< trim END
@@ -259,7 +259,7 @@ def Test_returning_null_object()
       var buffers = BufferList.new()
       echo buffers.Current()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_using_null_class()
@@ -276,7 +276,7 @@ def Test_class_interface_wrong_end()
         this.member = 'text'
       endinterface
   END
-  v9.CheckScriptFailure(lines, 'E476: Invalid command: endinterface, expected endclass')
+  v9.CheckSourceFailure(lines, 'E476: Invalid command: endinterface, expected endclass')
 
   lines =<< trim END
       vim9script
@@ -284,7 +284,7 @@ def Test_class_interface_wrong_end()
         this.member: string
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E476: Invalid command: endclass, expected endinterface')
+  v9.CheckSourceFailure(lines, 'E476: Invalid command: endclass, expected endinterface')
 enddef
 
 def Test_object_not_set()
@@ -299,7 +299,7 @@ def Test_object_not_set()
       var db = {'xyz': 789}
       echo db[state.value]
   END
-  v9.CheckScriptFailure(lines, 'E1360:')
+  v9.CheckSourceFailure(lines, 'E1360:')
 
   lines =<< trim END
       vim9script
@@ -317,7 +317,7 @@ def Test_object_not_set()
       enddef
       Func()
   END
-  v9.CheckScriptFailure(lines, 'E1360:')
+  v9.CheckSourceFailure(lines, 'E1360:')
 
   lines =<< trim END
       vim9script
@@ -337,7 +337,7 @@ def Test_object_not_set()
       var bg: Background           # UNINITIALIZED
       echo Colorscheme.new(bg).GetBackground()
   END
-  v9.CheckScriptFailure(lines, 'E1360:')
+  v9.CheckSourceFailure(lines, 'E1360:')
 
   # TODO: this should not give an error but be handled at runtime
   lines =<< trim END
@@ -356,7 +356,7 @@ def Test_object_not_set()
       enddef
       Func()
   END
-  v9.CheckScriptFailure(lines, 'E1363:')
+  v9.CheckSourceFailure(lines, 'E1363:')
 enddef
 
 def Test_null_object_assign_compare()
@@ -396,7 +396,7 @@ def Test_null_object_assign_compare()
     o2 = null_object
     assert_true(o2 == null)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_class_member_initializer()
@@ -432,7 +432,7 @@ def Test_class_member_initializer()
             '\d\+ RETURN object.*',
             instr)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_member_any_used_as_object()
@@ -456,7 +456,7 @@ def Test_member_any_used_as_object()
       F(outer_obj)
       assert_equal(1, inner_obj.value)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -482,7 +482,51 @@ def Test_member_any_used_as_object()
 
       Test_assign_to_nested_typed_member()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
+
+  # Try modifying a private variable using an "any" object
+  lines =<< trim END
+    vim9script
+
+    class Inner
+      this._value: string = ''
+    endclass
+
+    class Outer
+      this.inner: any
+    endclass
+
+    def F(outer: Outer)
+      outer.inner._value = 'b'
+    enddef
+
+    var inner_obj = Inner.new('a')
+    var outer_obj = Outer.new(inner_obj)
+    F(outer_obj)
+  END
+  v9.CheckSourceFailure(lines, 'E1333: Cannot access private member: _value')
+
+  # Try modifying a non-existing variable using an "any" object
+  lines =<< trim END
+    vim9script
+
+    class Inner
+      this.value: string = ''
+    endclass
+
+    class Outer
+      this.inner: any
+    endclass
+
+    def F(outer: Outer)
+      outer.inner.someval = 'b'
+    enddef
+
+    var inner_obj = Inner.new('a')
+    var outer_obj = Outer.new(inner_obj)
+    F(outer_obj)
+  END
+  v9.CheckSourceFailure(lines, 'E1326: Member not found on object "Inner": someval')
 enddef
 
 def Test_assignment_with_operator()
@@ -508,7 +552,7 @@ def Test_assignment_with_operator()
       AddToFoo(f)
       assert_equal(23, f.x)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # do the same thing, but through an interface
   lines =<< trim END
@@ -538,7 +582,7 @@ def Test_assignment_with_operator()
       AddToFoo(f)
       assert_equal(23, f.x)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_list_of_objects()
@@ -559,7 +603,7 @@ def Test_list_of_objects()
       var l: list<Foo> = [Foo.new()]
       ProcessList(l)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_expr_after_using_object()
@@ -578,7 +622,7 @@ def Test_expr_after_using_object()
 
       Foo()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_class_default_new()
@@ -606,7 +650,7 @@ def Test_class_default_new()
       assert_equal(1, pos.lnum)
       assert_equal(33, pos.col)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -629,7 +673,7 @@ def Test_class_default_new()
       assert_equal(4, chris.age)
       assert_equal("none", chris.education)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -644,7 +688,7 @@ def Test_class_default_new()
 
       var missing = Person.new()
   END
-  v9.CheckScriptFailure(lines, 'E119:')
+  v9.CheckSourceFailure(lines, 'E119:')
 enddef
 
 
@@ -677,7 +721,7 @@ def Test_class_new_with_object_member()
 
       Check()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -699,7 +743,7 @@ def Test_class_new_with_object_member()
 
       Check()
   END
-  v9.CheckScriptFailure(lines, 'E1013:')
+  v9.CheckSourceFailure(lines, 'E1013:')
 
   lines =<< trim END
       vim9script
@@ -721,7 +765,7 @@ def Test_class_new_with_object_member()
 
       Check()
   END
-  v9.CheckScriptFailure(lines, 'E1013:')
+  v9.CheckSourceFailure(lines, 'E1013:')
 enddef
 
 def Test_class_object_member_inits()
@@ -738,7 +782,7 @@ def Test_class_object_member_inits()
       assert_equal(1, pos.col)
       assert_equal(2, pos.addcol)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -747,7 +791,7 @@ def Test_class_object_member_inits()
         this.col = 1
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1022:')
+  v9.CheckSourceFailure(lines, 'E1022:')
 
   # If the type is not specified for a member, then it should be set during
   # object creation and not when defining the class.
@@ -770,7 +814,7 @@ def Test_class_object_member_inits()
       var a = A.new()
       assert_equal(init_count, 2)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Test for initializing an object member with an unknown variable/type
   lines =<< trim END
@@ -780,10 +824,11 @@ def Test_class_object_member_inits()
     endclass
     var a = A.new()
   END
-  v9.CheckScriptFailure(lines, 'E1001:')
+  v9.CheckSourceFailure(lines, 'E1001:')
 enddef
 
-def Test_class_object_member_access()
+" Test for instance variable access
+def Test_instance_variable_access()
   var lines =<< trim END
       vim9script
       class Triple
@@ -807,9 +852,9 @@ def Test_class_object_member_access()
       trip.three = 33
       assert_equal(33, trip.three)
 
-      assert_fails('trip.four = 4', 'E1334')
+      assert_fails('trip.four = 4', 'E1326')
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Test for a public member variable name beginning with an underscore
   lines =<< trim END
@@ -818,7 +863,7 @@ def Test_class_object_member_access()
       public this._val = 10
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1332:')
+  v9.CheckSourceFailure(lines, 'E1332:')
 
   lines =<< trim END
       vim9script
@@ -854,7 +899,7 @@ def Test_class_object_member_access()
       enddef
       CheckCar()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -870,7 +915,7 @@ def Test_class_object_member_access()
       var c = MyCar.new("abc")
       var c = MyCar.new("def")
   END
-  v9.CheckScriptFailure(lines, 'E1041:')
+  v9.CheckSourceFailure(lines, 'E1041:')
 
   lines =<< trim END
       vim9script
@@ -896,7 +941,7 @@ def Test_class_object_member_access()
             .Add(2)
             .x
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Test for "public" cannot be abbreviated
   lines =<< trim END
@@ -905,7 +950,7 @@ def Test_class_object_member_access()
       pub this.val = 1
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1065:')
+  v9.CheckSourceFailure(lines, 'E1065:')
 
   # Test for "public" keyword must be followed by "this" or "static".
   lines =<< trim END
@@ -914,25 +959,53 @@ def Test_class_object_member_access()
       public val = 1
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1331:')
+  v9.CheckSourceFailure(lines, 'E1331:')
 
-  # Test for "static" cannot be abbreviated
+  # Modify a instance variable using the class name in the script context
   lines =<< trim END
     vim9script
-    class Something
-      stat this.val = 1
+    class A
+      public this.val = 1
     endclass
+    A.val = 1
   END
-  v9.CheckScriptFailure(lines, 'E1065:')
+  v9.CheckSourceFailure(lines, 'E1376: Object member "val" accessible only using class "A" object')
 
-  # Test for "static" cannot be followed by "this".
+  # Read a instance variable using the class name in the script context
   lines =<< trim END
     vim9script
-    class Something
-      static this.val = 1
+    class A
+      public this.val = 1
     endclass
+    var i = A.val
   END
-  v9.CheckScriptFailure(lines, 'E1368: Static cannot be followed by "this" in a member name')
+  v9.CheckSourceFailure(lines, 'E1376: Object member "val" accessible only using class "A" object')
+
+  # Modify a instance variable using the class name in a def function
+  lines =<< trim END
+    vim9script
+    class A
+      public this.val = 1
+    endclass
+    def T()
+      A.val = 1
+    enddef
+    T()
+  END
+  v9.CheckSourceFailure(lines, 'E1376: Object member "val" accessible only using class "A" object')
+
+  # Read a instance variable using the class name in a def function
+  lines =<< trim END
+    vim9script
+    class A
+      public this.val = 1
+    endclass
+    def T()
+      var i = A.val
+    enddef
+    T()
+  END
+  v9.CheckSourceFailure(lines, 'E1376: Object member "val" accessible only using class "A" object')
 
   # Access from child class extending a class:
   lines =<< trim END
@@ -941,10 +1014,6 @@ def Test_class_object_member_access()
         this.ro_obj_var = 10
         public this.rw_obj_var = 20
         this._priv_obj_var = 30
-
-        static ro_class_var = 40
-        public static rw_class_var = 50
-        static _priv_class_var = 60
       endclass
 
       class B extends A
@@ -956,19 +1025,89 @@ def Test_class_object_member_access()
           this.rw_obj_var = 0
           x = this._priv_obj_var
           this._priv_obj_var = 0
+        enddef
+      endclass
 
-          x = ro_class_var
-          ro_class_var = 0
-          x = rw_class_var
-          rw_class_var = 0
-          x = _priv_class_var
-          _priv_class_var = 0
+      var b = B.new()
+      b.Foo()
+  END
+  v9.CheckSourceSuccess(lines)
+enddef
 
-          x = A.ro_class_var
-          A.ro_class_var = 0
-          x = A.rw_class_var
-          A.rw_class_var = 0
-          x = A._priv_class_var
+" Test for class variable access
+def Test_class_variable_access()
+  # Test for "static" cannot be abbreviated
+  var lines =<< trim END
+    vim9script
+    class Something
+      stat this.val = 1
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1065:')
+
+  # Test for "static" cannot be followed by "this".
+  lines =<< trim END
+    vim9script
+    class Something
+      static this.val = 1
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1368: Static cannot be followed by "this" in a member name')
+
+  # Test for "static" cannot be followed by "public".
+  lines =<< trim END
+    vim9script
+    class Something
+      static public val = 1
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1022: Type or initialization required')
+
+  # A readonly class variable cannot be modified from a child class
+  lines =<< trim END
+      vim9script
+      class A
+        static ro_class_var = 40
+      endclass
+
+      class B extends A
+        def Foo()
+          A.ro_class_var = 50
+        enddef
+      endclass
+
+      var b = B.new()
+      b.Foo()
+  END
+  v9.CheckSourceFailure(lines, 'E46: Cannot change read-only variable "ro_class_var"')
+
+  # A private class variable cannot be accessed from a child class
+  lines =<< trim END
+      vim9script
+      class A
+        static _priv_class_var = 60
+      endclass
+
+      class B extends A
+        def Foo()
+          var i = A._priv_class_var
+        enddef
+      endclass
+
+      var b = B.new()
+      b.Foo()
+  END
+  v9.CheckSourceFailure(lines, 'E1333: Cannot access private member: _priv_class_var')
+
+  # A private class variable cannot be modified from a child class
+  lines =<< trim END
+      vim9script
+      class A
+        static _priv_class_var = 60
+      endclass
+
+      class B extends A
+        def Foo()
           A._priv_class_var = 0
         enddef
       endclass
@@ -976,7 +1115,37 @@ def Test_class_object_member_access()
       var b = B.new()
       b.Foo()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceFailure(lines, 'E1333: Cannot access private member: _priv_class_var')
+
+  # Access from child class extending a class and from script context
+  lines =<< trim END
+      vim9script
+      class A
+        static ro_class_var = 10
+        public static rw_class_var = 20
+        static _priv_class_var = 30
+      endclass
+
+      class B extends A
+        def Foo()
+          var x: number
+          x = A.ro_class_var
+          assert_equal(10, x)
+          x = A.rw_class_var
+          assert_equal(25, x)
+          A.rw_class_var = 20
+          assert_equal(20, A.rw_class_var)
+        enddef
+      endclass
+
+      assert_equal(10, A.ro_class_var)
+      assert_equal(20, A.rw_class_var)
+      A.rw_class_var = 25
+      assert_equal(25, A.rw_class_var)
+      var b = B.new()
+      b.Foo()
+  END
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_class_object_compare()
@@ -1005,8 +1174,8 @@ def Test_class_object_compare()
       assert_notequal(i1, io2)
   END
 
-  v9.CheckScriptSuccess(class_lines + test_lines)
-  v9.CheckScriptSuccess(
+  v9.CheckSourceSuccess(class_lines + test_lines)
+  v9.CheckSourceSuccess(
       class_lines + ['def Test()'] + test_lines + ['enddef', 'Test()'])
 
   for op in ['>', '>=', '<', '<=', '=~', '!~']
@@ -1015,8 +1184,8 @@ def Test_class_object_compare()
           'var i2 = Item.new()',
           'echo i1 ' .. op .. ' i2',
           ]
-    v9.CheckScriptFailure(class_lines + op_lines, 'E1153: Invalid operation for object')
-    v9.CheckScriptFailure(class_lines
+    v9.CheckSourceFailure(class_lines + op_lines, 'E1153: Invalid operation for object')
+    v9.CheckSourceFailure(class_lines
           + ['def Test()'] + op_lines + ['enddef', 'Test()'], 'E1153: Invalid operation for object')
   endfor
 enddef
@@ -1042,7 +1211,7 @@ def Test_object_type()
 
       t = m
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -1056,7 +1225,7 @@ def Test_object_type()
 
       var o: One = Two.new()
   END
-  v9.CheckScriptFailure(lines, 'E1012: Type mismatch; expected object<One> but got object<Two>')
+  v9.CheckSourceFailure(lines, 'E1012: Type mismatch; expected object<One> but got object<Two>')
 
   lines =<< trim END
       vim9script
@@ -1074,7 +1243,7 @@ def Test_object_type()
       var o: One = Two.new(5)
       assert_equal(5, o.GetMember())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -1094,7 +1263,7 @@ def Test_object_type()
 
       echo Fn(Num.new(4))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_class_member()
@@ -1116,7 +1285,7 @@ def Test_class_member()
       assert_equal(0, TextPos.counter)
       TextPos.AddToCounter(3)
       assert_equal(3, TextPos.counter)
-      assert_fails('echo TextPos.noSuchMember', 'E1338:')
+      assert_fails('echo TextPos.noSuchMember', 'E1337:')
 
       def GetCounter(): number
         return TextPos.counter
@@ -1136,7 +1305,7 @@ def Test_class_member()
       TextPos.anybody += 5
       assert_equal(17, TextPos.anybody)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # example in the help
   lines =<< trim END
@@ -1155,7 +1324,7 @@ def Test_class_member()
         var to7 = OtherThing.new(7)
         assert_equal(10, OtherThing.totalSize)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # using static class member twice
   lines =<< trim END
@@ -1172,7 +1341,7 @@ def Test_class_member()
       assert_equal('some text', HTML.MacroSubstitute('some text'))
       assert_equal('some text', HTML.MacroSubstitute('some text'))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # access private member in lambda
   lines =<< trim END
@@ -1190,7 +1359,7 @@ def Test_class_member()
       var foo = Foo.new()
       assert_equal(5, foo.Add(5))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # access private member in lambda body
   lines =<< trim END
@@ -1211,7 +1380,7 @@ def Test_class_member()
       var foo = Foo.new()
       assert_equal(13, foo.Add(7))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # check shadowing
   lines =<< trim END
@@ -1227,7 +1396,7 @@ def Test_class_member()
       var s = Some.new()
       s.Method(7)
   END
-  v9.CheckScriptFailure(lines, 'E1340: Argument already declared in the class: count')
+  v9.CheckSourceFailure(lines, 'E1340: Argument already declared in the class: count')
 
   lines =<< trim END
       vim9script
@@ -1243,7 +1412,7 @@ def Test_class_member()
       var s = Some.new()
       s.Method(7)
   END
-  v9.CheckScriptFailure(lines, 'E1341: Variable already declared in the class: count')
+  v9.CheckSourceFailure(lines, 'E1341: Variable already declared in the class: count')
 
   # Test for using an invalid type for a member variable
   lines =<< trim END
@@ -1252,7 +1421,7 @@ def Test_class_member()
       this.val: xxx
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1010:')
+  v9.CheckSourceFailure(lines, 'E1010:')
 
   # Test for setting a member on a null object
   lines =<< trim END
@@ -1267,7 +1436,7 @@ def Test_class_member()
     enddef
     F()
   END
-  v9.CheckScriptFailure(lines, 'E1360: Using a null object')
+  v9.CheckSourceFailure(lines, 'E1360: Using a null object')
 
   # Test for accessing a member on a null object
   lines =<< trim END
@@ -1282,7 +1451,7 @@ def Test_class_member()
     enddef
     F()
   END
-  v9.CheckScriptFailure(lines, 'E1360: Using a null object')
+  v9.CheckSourceFailure(lines, 'E1360: Using a null object')
 
   # Test for setting a member on a null object, at script level
   lines =<< trim END
@@ -1295,7 +1464,7 @@ def Test_class_member()
     obj.val = ""
   END
   # FIXME(in source): this should give E1360 as well!
-  v9.CheckScriptFailure(lines, 'E1012: Type mismatch; expected object<A> but got string')
+  v9.CheckSourceFailure(lines, 'E1012: Type mismatch; expected object<A> but got string')
 
   # Test for accessing a member on a null object, at script level
   lines =<< trim END
@@ -1307,7 +1476,7 @@ def Test_class_member()
     var obj: A
     echo obj.val
   END
-  v9.CheckScriptFailure(lines, 'E1360: Using a null object')
+  v9.CheckSourceFailure(lines, 'E1360: Using a null object')
 
   # Test for no space before or after the '=' when initializing a member
   # variable
@@ -1317,14 +1486,14 @@ def Test_class_member()
       this.val: number= 10
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1004:')
+  v9.CheckSourceFailure(lines, 'E1004:')
   lines =<< trim END
     vim9script
     class A
       this.val: number =10
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1004:')
+  v9.CheckSourceFailure(lines, 'E1004:')
 
   # Access a non-existing member
   lines =<< trim END
@@ -1334,7 +1503,7 @@ def Test_class_member()
     var a = A.new()
     var v = a.bar
   END
-  v9.CheckScriptFailure(lines, 'E1326:')
+  v9.CheckSourceFailure(lines, 'E1326: Member not found on object "A": bar')
 enddef
 
 func Test_class_garbagecollect()
@@ -1351,7 +1520,7 @@ func Test_class_garbagecollect()
       call test_garbagecollect_now()
       echo Point.pl Point.pd
   END
-  call v9.CheckScriptSuccess(lines)
+  call v9.CheckSourceSuccess(lines)
 
   let lines =<< trim END
       vim9script
@@ -1378,7 +1547,7 @@ func Test_class_garbagecollect()
       view = MyView.new()
       test_garbagecollect_now()
   END
-  call v9.CheckScriptSuccess(lines)
+  call v9.CheckSourceSuccess(lines)
 endfunc
 
 " Test interface garbage collection
@@ -1432,7 +1601,7 @@ func Test_interface_garbagecollect()
     assert_equal(60, A.ClassFoo())
     assert_equal(150, o.ObjFoo())
   END
-  call v9.CheckScriptSuccess(lines)
+  call v9.CheckSourceSuccess(lines)
 endfunc
 
 def Test_class_function()
@@ -1458,7 +1627,7 @@ def Test_class_function()
       var v2 = Value.new(7)
       assert_equal(2, Value.GetCount())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Test for cleaning up after a class definition failure when using class
   # functions.
@@ -1470,7 +1639,7 @@ def Test_class_function()
       aaa
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1318:')
+  v9.CheckSourceFailure(lines, 'E1318:')
 enddef
 
 def Test_class_defcompile()
@@ -1485,7 +1654,7 @@ def Test_class_defcompile()
 
       defcompile C.Fo
   END
-  v9.CheckScriptFailure(lines, 'E1012: Type mismatch; expected string but got number')
+  v9.CheckSourceFailure(lines, 'E1012: Type mismatch; expected string but got number')
 
   lines =<< trim END
       vim9script
@@ -1498,7 +1667,7 @@ def Test_class_defcompile()
 
       defcompile C.Fc
   END
-  v9.CheckScriptFailure(lines, 'E1012: Type mismatch; expected number but got string')
+  v9.CheckSourceFailure(lines, 'E1012: Type mismatch; expected number but got string')
 
   lines =<< trim END
       vim9script
@@ -1510,14 +1679,14 @@ def Test_class_defcompile()
 
       defcompile C.new
   END
-  v9.CheckScriptFailure(lines, 'E1370: Cannot define a "new" function as static')
+  v9.CheckSourceFailure(lines, 'E1370: Cannot define a "new" function as static')
 
   # Trying to compile a function using a non-existing class variable
   lines =<< trim END
     vim9script
     defcompile x.Foo()
   END
-  v9.CheckScriptFailure(lines, 'E475:')
+  v9.CheckSourceFailure(lines, 'E475:')
 
   # Trying to compile a function using a variable which is not a class
   lines =<< trim END
@@ -1525,7 +1694,7 @@ def Test_class_defcompile()
     var x: number
     defcompile x.Foo()
   END
-  v9.CheckScriptFailure(lines, 'E475:')
+  v9.CheckSourceFailure(lines, 'E475:')
 
   # Trying to compile a function without specifying the name
   lines =<< trim END
@@ -1534,7 +1703,7 @@ def Test_class_defcompile()
     endclass
     defcompile A.
   END
-  v9.CheckScriptFailure(lines, 'E475:')
+  v9.CheckSourceFailure(lines, 'E475:')
 
   # Trying to compile a non-existing class object member function
   lines =<< trim END
@@ -1544,7 +1713,7 @@ def Test_class_defcompile()
     var a = A.new()
     defcompile a.Foo()
   END
-  v9.CheckScriptFailureList(lines, ['E1334:', 'E475:'])
+  v9.CheckSourceFailureList(lines, ['E1326:', 'E475:'])
 enddef
 
 def Test_class_object_to_string()
@@ -1560,7 +1729,7 @@ def Test_class_object_to_string()
       var pos = TextPosition.new()
       assert_equal("object of TextPosition {lnum: 1, col: 22}", string(pos))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_interface_basics()
@@ -1572,14 +1741,14 @@ def Test_interface_basics()
         def GetCount(): number
       endinterface
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       interface SomethingWrong
         static count = 7
       endinterface
   END
-  v9.CheckScriptFailure(lines, 'E1342:')
+  v9.CheckSourceFailure(lines, 'E1342:')
 
   lines =<< trim END
       vim9script
@@ -1589,7 +1758,7 @@ def Test_interface_basics()
         def Method(count: number)
       endinterface
   END
-  v9.CheckScriptFailure(lines, 'E1340: Argument already declared in the class: count', 5)
+  v9.CheckSourceFailure(lines, 'E1340: Argument already declared in the class: count', 5)
 
   lines =<< trim END
       vim9script
@@ -1601,7 +1770,7 @@ def Test_interface_basics()
   END
   # The argument name and the object member name are the same, but this is not a
   # problem because object members are always accessed with the "this." prefix.
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -1609,7 +1778,7 @@ def Test_interface_basics()
         static count = 7
       endinterface
   END
-  v9.CheckScriptFailure(lines, 'E1343: Interface name must start with an uppercase letter: somethingWrong')
+  v9.CheckSourceFailure(lines, 'E1343: Interface name must start with an uppercase letter: somethingWrong')
 
   lines =<< trim END
       vim9script
@@ -1619,7 +1788,7 @@ def Test_interface_basics()
         def GetCount(): number
       endinterface
   END
-  v9.CheckScriptFailure(lines, 'E1344:')
+  v9.CheckSourceFailure(lines, 'E1344:')
 
   lines =<< trim END
       vim9script
@@ -1631,7 +1800,7 @@ def Test_interface_basics()
         enddef
       endinterface
   END
-  v9.CheckScriptFailure(lines, 'E1345: Not a valid command in an interface: return 5')
+  v9.CheckSourceFailure(lines, 'E1345: Not a valid command in an interface: return 5')
 
   lines =<< trim END
       vim9script
@@ -1699,7 +1868,7 @@ def Test_class_implements_interface()
         enddef
       endclass
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -1712,7 +1881,7 @@ def Test_class_implements_interface()
         static count: number
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1350:')
+  v9.CheckSourceFailure(lines, 'E1350:')
 
   lines =<< trim END
       vim9script
@@ -1725,7 +1894,7 @@ def Test_class_implements_interface()
         static count: number
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1351: Duplicate interface after "implements": Some')
+  v9.CheckSourceFailure(lines, 'E1351: Duplicate interface after "implements": Some')
 
   lines =<< trim END
       vim9script
@@ -1742,7 +1911,7 @@ def Test_class_implements_interface()
         enddef
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1348: Member "counter" of interface "Some" not implemented')
+  v9.CheckSourceFailure(lines, 'E1348: Member "counter" of interface "Some" not implemented')
 
   lines =<< trim END
       vim9script
@@ -1759,7 +1928,7 @@ def Test_class_implements_interface()
         enddef
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1349: Function "Methods" of interface "Some" not implemented')
+  v9.CheckSourceFailure(lines, 'E1349: Function "Methods" of interface "Some" not implemented')
 
   # Check different order of members in class and interface works.
   lines =<< trim END
@@ -1789,7 +1958,7 @@ def Test_class_implements_interface()
 
       Test()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Interface name after "extends" doesn't end in a space or NUL character
   lines =<< trim END
@@ -1799,7 +1968,7 @@ def Test_class_implements_interface()
     class B extends A"
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1315:')
+  v9.CheckSourceFailure(lines, 'E1315:')
 
   # Trailing characters after a class name
   lines =<< trim END
@@ -1807,7 +1976,7 @@ def Test_class_implements_interface()
     class A bbb
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E488:')
+  v9.CheckSourceFailure(lines, 'E488:')
 
   # using "implements" with a non-existing class
   lines =<< trim END
@@ -1815,7 +1984,7 @@ def Test_class_implements_interface()
     class A implements B
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1346:')
+  v9.CheckSourceFailure(lines, 'E1346:')
 
   # using "implements" with a regular class
   lines =<< trim END
@@ -1825,7 +1994,7 @@ def Test_class_implements_interface()
     class B implements A
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1347:')
+  v9.CheckSourceFailure(lines, 'E1347:')
 
   # using "implements" with a variable
   lines =<< trim END
@@ -1834,7 +2003,7 @@ def Test_class_implements_interface()
     class A implements T
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1347:')
+  v9.CheckSourceFailure(lines, 'E1347:')
 
   # all the class methods in an "interface" should be implemented
   lines =<< trim END
@@ -1845,7 +2014,7 @@ def Test_class_implements_interface()
     class B implements A
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1349:')
+  v9.CheckSourceFailure(lines, 'E1349:')
 
   # implements should be followed by a white space
   lines =<< trim END
@@ -1855,7 +2024,7 @@ def Test_class_implements_interface()
     class B implements A;
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1315:')
+  v9.CheckSourceFailure(lines, 'E1315:')
 
   lines =<< trim END
       vim9script
@@ -1871,7 +2040,7 @@ def Test_class_implements_interface()
         static matching: bool
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1406: Member "not_matching": type mismatch, expected number but got string')
+  v9.CheckSourceFailure(lines, 'E1406: Member "not_matching": type mismatch, expected number but got string')
 
   lines =<< trim END
       vim9script
@@ -1884,7 +2053,7 @@ def Test_class_implements_interface()
         enddef
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1407: Method "IsEven": type mismatch, expected func(number): bool but got func(number): string')
+  v9.CheckSourceFailure(lines, 'E1407: Method "IsEven": type mismatch, expected func(number): bool but got func(number): string')
 
   lines =<< trim END
       vim9script
@@ -1897,7 +2066,7 @@ def Test_class_implements_interface()
         enddef
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1407: Method "IsEven": type mismatch, expected func(number): bool but got func(bool): bool')
+  v9.CheckSourceFailure(lines, 'E1407: Method "IsEven": type mismatch, expected func(number): bool but got func(bool): bool')
 
   lines =<< trim END
       vim9script
@@ -1910,7 +2079,7 @@ def Test_class_implements_interface()
         enddef
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1407: Method "IsEven": type mismatch, expected func(number): bool but got func(number, ...list<number>): bool')
+  v9.CheckSourceFailure(lines, 'E1407: Method "IsEven": type mismatch, expected func(number): bool but got func(number, ...list<number>): bool')
 
   # access superclass interface members from subclass, mix variable order
   lines =<< trim END
@@ -1939,8 +2108,6 @@ def Test_class_implements_interface()
 
     class B extends A
         def new()
-            svar1 = 21
-            svar2 = 22
             this.mvar1 = 121
             this.mvar2 = 122
         enddef
@@ -1948,8 +2115,6 @@ def Test_class_implements_interface()
 
     class C extends B
         def new()
-            svar1 = 31
-            svar2 = 32
             this.mvar1 = 131
             this.mvar2 = 132
         enddef
@@ -1967,7 +2132,7 @@ def Test_class_implements_interface()
     assert_equal([121, 122], F2(ob))
     assert_equal([131, 132], F2(oc))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Access superclass interface members from subclass, mix variable order.
   # Two interfaces, one on A, one on B; each has both kinds of variables
@@ -2007,8 +2172,6 @@ def Test_class_implements_interface()
         public this.mvar3: number
         public this.mvar4: number
         def new()
-            svar1 = 21
-            svar2 = 22
             svar3 = 23
             svar4 = 24
             this.mvar1 = 121
@@ -2021,10 +2184,6 @@ def Test_class_implements_interface()
     class C extends B
         public static svar5: number
         def new()
-            svar1 = 31
-            svar2 = 32
-            svar3 = 33
-            svar4 = 34
             svar5 = 1001
             this.mvar1 = 131
             this.mvar2 = 132
@@ -2049,7 +2208,7 @@ def Test_class_implements_interface()
     assert_equal([[121, 122], [123, 124]], [F2(ob), F4(ob)])
     assert_equal([[131, 132], [133, 134]], [F2(oc), F4(oc)])
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_call_interface_method()
@@ -2074,7 +2233,7 @@ def Test_call_interface_method()
     assert_equal('child', g:result)
     unlet g:result
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
     vim9script
@@ -2099,7 +2258,7 @@ def Test_call_interface_method()
     assert_equal('child', g:result)
     unlet g:result
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # method of interface returns a value
   lines =<< trim END
@@ -2125,7 +2284,7 @@ def Test_call_interface_method()
     assert_equal('child/resource', g:result)
     unlet g:result
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
     vim9script
@@ -2152,7 +2311,7 @@ def Test_call_interface_method()
     assert_equal('child/resource', g:result)
     unlet g:result
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
 
   # No class that implements the interface.
@@ -2170,7 +2329,7 @@ def Test_call_interface_method()
 
       defcompile
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_class_used_as_type()
@@ -2187,7 +2346,7 @@ def Test_class_used_as_type()
       assert_equal(2, p.x)
       assert_equal(33, p.y)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -2206,7 +2365,7 @@ def Test_class_used_as_type()
       var hx = p
       assert_equal(2, hx.x)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -2219,7 +2378,7 @@ def Test_class_used_as_type()
       var p: Point
       p = 'text'
   END
-  v9.CheckScriptFailure(lines, 'E1012: Type mismatch; expected object<Point> but got string')
+  v9.CheckSourceFailure(lines, 'E1012: Type mismatch; expected object<Point> but got string')
 enddef
 
 def Test_class_extends()
@@ -2243,7 +2402,7 @@ def Test_class_extends()
       assert_equal(1, o.GetOne())
       assert_equal(3, o.GetTotal())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -2257,7 +2416,7 @@ def Test_class_extends()
       assert_equal(3, o.one)
       assert_equal(44, o.two)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -2268,7 +2427,7 @@ def Test_class_extends()
         this.two = 2
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1352: Duplicate "extends"')
+  v9.CheckSourceFailure(lines, 'E1352: Duplicate "extends"')
 
   lines =<< trim END
       vim9script
@@ -2276,7 +2435,7 @@ def Test_class_extends()
         this.two = 2
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1353: Class name not found: BaseClass')
+  v9.CheckSourceFailure(lines, 'E1353: Class name not found: BaseClass')
 
   lines =<< trim END
       vim9script
@@ -2285,7 +2444,7 @@ def Test_class_extends()
         this.two = 2
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1354: Cannot extend SomeVar')
+  v9.CheckSourceFailure(lines, 'E1354: Cannot extend SomeVar')
 
   lines =<< trim END
       vim9script
@@ -2306,7 +2465,7 @@ def Test_class_extends()
       var o = Child.new('John', 42)
       assert_equal('John: 42', o.ToString())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -2320,7 +2479,7 @@ def Test_class_extends()
         enddef
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1355: Duplicate function: ToString')
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: ToString')
 
   lines =<< trim END
       vim9script
@@ -2333,7 +2492,7 @@ def Test_class_extends()
       var o = Child.new(42)
       echo o.ToString()
   END
-  v9.CheckScriptFailure(lines, 'E1356:')
+  v9.CheckSourceFailure(lines, 'E1356:')
 
   lines =<< trim END
       vim9script
@@ -2350,7 +2509,7 @@ def Test_class_extends()
       enddef
       echo ToString()
   END
-  v9.CheckScriptFailure(lines, 'E1357:')
+  v9.CheckSourceFailure(lines, 'E1357:')
 
   lines =<< trim END
       vim9script
@@ -2363,7 +2522,7 @@ def Test_class_extends()
       var o = Child.new(42)
       echo o.ToString()
   END
-  v9.CheckScriptFailure(lines, 'E1358:')
+  v9.CheckSourceFailure(lines, 'E1358:')
 
   lines =<< trim END
       vim9script
@@ -2384,7 +2543,7 @@ def Test_class_extends()
       var o = Child.new('John', 42)
       assert_equal('Base class: 42', o.ToString())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -2401,7 +2560,7 @@ def Test_class_extends()
       endclass
       var c = Child.new()
   END
-  v9.CheckScriptFailure(lines, 'E1325: Method not found on class "Child": new(')
+  v9.CheckSourceFailure(lines, 'E1375: Class member "new" accessible only using class "Child"')
 
   # base class with more than one object member
   lines =<< trim END
@@ -2421,7 +2580,7 @@ def Test_class_extends()
       var v = Success.new('asdf')
       assert_equal("object of Success {success: true, value: 'asdf'}", string(v))
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # class name after "extends" doesn't end in a space or NUL character
   lines =<< trim END
@@ -2431,7 +2590,7 @@ def Test_class_extends()
     class B extends A"
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1315:')
+  v9.CheckSourceFailure(lines, 'E1315:')
 enddef
 
 def Test_using_base_class()
@@ -2470,7 +2629,7 @@ def Test_using_base_class()
     With(ChildEE.new())
     assert_equal('42/finally/exit', g:result)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
   unlet g:result
 
   # Using super, Child invokes Base method which has optional arg. #12471
@@ -2493,7 +2652,7 @@ def Test_using_base_class()
     var obj = Child.new()
     assert_equal(true, obj.success)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 
@@ -2536,7 +2695,7 @@ def Test_abstract_class()
       assert_equal('Peter', p.name)
       assert_equal(42, p.age)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
       vim9script
@@ -2548,14 +2707,14 @@ def Test_abstract_class()
       endclass
       var p = Base.new('Peter')
   END
-  v9.CheckScriptFailure(lines, 'E1325: Method not found on class "Base": new(')
+  v9.CheckSourceFailure(lines, 'E1325: Method not found on class "Base": new')
 
   lines =<< trim END
       abstract class Base
         this.name: string
       endclass
   END
-  v9.CheckScriptFailure(lines, 'E1316:')
+  v9.CheckSourceFailure(lines, 'E1316:')
 
   # Abstract class cannot have a "new" function
   lines =<< trim END
@@ -2565,7 +2724,7 @@ def Test_abstract_class()
       enddef
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1359:')
+  v9.CheckSourceFailure(lines, 'E1359:')
 enddef
 
 def Test_closure_in_class()
@@ -2583,7 +2742,7 @@ def Test_closure_in_class()
       Foo.new()
       assert_equal(['A'], g:result)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_call_constructor_from_legacy()
@@ -2606,7 +2765,7 @@ def Test_call_constructor_from_legacy()
       legacy call p.new()
       assert_equal('true', newCalled)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_defer_with_object()
@@ -2635,7 +2794,7 @@ def Test_defer_with_object()
       })
       assert_equal('entered/called/exited', g:result)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
   unlet g:result
 
   lines =<< trim END
@@ -2672,7 +2831,7 @@ def Test_defer_with_object()
       })
       assert_equal('entered-child/called/exited-child', g:result)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
   unlet g:result
 enddef
 
@@ -2712,7 +2871,7 @@ def Test_extends_method_crashes_vim()
 
     p.Set(true)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for calling a method in a class that is extended
@@ -2747,7 +2906,7 @@ def Test_call_method_in_extended_class()
     assert_true(prop_init_called)
     assert_true(prop_register_called)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_instanceof()
@@ -2794,7 +2953,7 @@ def Test_instanceof()
     enddef
     Foo()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for calling a method in the parent class that is extended partially.
@@ -2832,7 +2991,7 @@ def Test_call_method_in_parent_class()
     var foo2 = Foo.new()
     var l = Stack(foo1, foo2)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for calling methods from three levels of classes
@@ -2906,7 +3065,7 @@ def Test_multi_level_method_call()
     assert_equal(0, B_func3)
     assert_equal(3, C_func3)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for using members from three levels of classes
@@ -2949,7 +3108,7 @@ def Test_multi_level_member_access()
     assert_equal(2, cobj.val2)
     assert_equal(1, cobj.val3)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test expansion of <stack> with class methods.
@@ -2973,7 +3132,7 @@ def Test_stack_expansion_with_methods()
 
     F()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test the return type of the new() constructor
@@ -3006,7 +3165,7 @@ def Test_new_return_type()
     enddef
     F()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # new() uses the default return type and an empty 'return' statement
   lines =<< trim END
@@ -3037,7 +3196,7 @@ def Test_new_return_type()
     enddef
     F()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # new() uses "any" return type and returns "this"
   lines =<< trim END
@@ -3054,7 +3213,7 @@ def Test_new_return_type()
       enddef
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1365:')
+  v9.CheckSourceFailure(lines, 'E1365:')
 
   # new() uses 'Dict' return type and returns a Dict
   lines =<< trim END
@@ -3072,7 +3231,7 @@ def Test_new_return_type()
     var c = C.new()
     assert_equal('object<C>', typename(c))
   END
-  v9.CheckScriptFailure(lines, 'E1365:')
+  v9.CheckSourceFailure(lines, 'E1365:')
 enddef
 
 " Test for checking a member initialization type at run time.
@@ -3098,7 +3257,7 @@ def Test_runtime_type_check_for_member_init()
     var c1 = C.new()
     var c2 = C.new()
   END
-  v9.CheckScriptFailure(lines, 'E1012:')
+  v9.CheckSourceFailure(lines, 'E1012:')
 enddef
 
 " Test for locking a variable referring to an object and reassigning to another
@@ -3135,7 +3294,7 @@ def Test_object_lockvar()
     G()
     assert_equal(2, current.val)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for a private object method
@@ -3152,7 +3311,7 @@ def Test_private_object_method()
     var a = A.new()
     a._Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Try calling a private method using an object (from a def function)
   lines =<< trim END
@@ -3169,7 +3328,7 @@ def Test_private_object_method()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Use a private method from another object method (in script context)
   lines =<< trim END
@@ -3186,7 +3345,7 @@ def Test_private_object_method()
     var a = A.new()
     assert_equal(1234, a.Bar())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Use a private method from another object method (def function context)
   lines =<< trim END
@@ -3206,7 +3365,7 @@ def Test_private_object_method()
     enddef
     T()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Try calling a private method without the "this" prefix
   lines =<< trim END
@@ -3223,7 +3382,7 @@ def Test_private_object_method()
     var a = A.new()
     a.Bar()
   END
-  v9.CheckScriptFailure(lines, 'E117: Unknown function: _Foo')
+  v9.CheckSourceFailure(lines, 'E117: Unknown function: _Foo')
 
   # Try calling a private method using the class name
   lines =<< trim END
@@ -3236,7 +3395,7 @@ def Test_private_object_method()
     endclass
     A._Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1325: Method not found on class "A": _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo')
 
   # Try to use "public" keyword when defining a private method
   lines =<< trim END
@@ -3249,7 +3408,7 @@ def Test_private_object_method()
     var a = A.new()
     a._Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1331: Public must be followed by "this" or "static"')
+  v9.CheckSourceFailure(lines, 'E1331: Public must be followed by "this" or "static"')
 
   # Define two private methods with the same name
   lines =<< trim END
@@ -3263,7 +3422,7 @@ def Test_private_object_method()
     endclass
     var a = A.new()
   END
-  v9.CheckScriptFailure(lines, 'E1355: Duplicate function: _Foo')
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: _Foo')
 
   # Define a private method and a object method with the same name
   lines =<< trim END
@@ -3277,7 +3436,7 @@ def Test_private_object_method()
     endclass
     var a = A.new()
   END
-  v9.CheckScriptFailure(lines, 'E1355: Duplicate function: Foo')
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: Foo')
 
   # Define an object method and a private method with the same name
   lines =<< trim END
@@ -3291,7 +3450,7 @@ def Test_private_object_method()
     endclass
     var a = A.new()
   END
-  v9.CheckScriptFailure(lines, 'E1355: Duplicate function: _Foo')
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: _Foo')
 
   # Call a public method and a private method from a private method
   lines =<< trim END
@@ -3315,7 +3474,7 @@ def Test_private_object_method()
     var a = A.new()
     a.T()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Try calling a private method from another class
   lines =<< trim END
@@ -3335,7 +3494,7 @@ def Test_private_object_method()
     var b = B.new()
     b.Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Call a private object method from a child class object method
   lines =<< trim END
@@ -3357,7 +3516,7 @@ def Test_private_object_method()
     var c = C.new()
     assert_equal(1234, c.Baz())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Call a private object method from a child class object
   lines =<< trim END
@@ -3378,7 +3537,7 @@ def Test_private_object_method()
     var c = C.new()
     assert_equal(1234, c._Foo())
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Using "_" prefix in a method name should fail outside of a class
   lines =<< trim END
@@ -3388,7 +3547,7 @@ def Test_private_object_method()
     enddef
     var a = _Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1267: Function name must start with a capital: _Foo(): number')
+  v9.CheckSourceFailure(lines, 'E1267: Function name must start with a capital: _Foo(): number')
 enddef
 
 " Test for an private class method
@@ -3404,7 +3563,7 @@ def Test_private_class_method()
     endclass
     A._Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Try calling a class private method (from a def function)
   lines =<< trim END
@@ -3420,7 +3579,7 @@ def Test_private_class_method()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Try calling a class private method using an object (at the script level)
   lines =<< trim END
@@ -3434,7 +3593,7 @@ def Test_private_class_method()
     var a = A.new()
     a._Foo()
   END
-  v9.CheckScriptFailure(lines, 'E1325: Method not found on class "A": _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo')
 
   # Try calling a class private method using an object (from a def function)
   lines =<< trim END
@@ -3451,7 +3610,7 @@ def Test_private_class_method()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1325: Method not found on class "A": _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo')
 
   # Use a class private method from an object method
   lines =<< trim END
@@ -3468,7 +3627,7 @@ def Test_private_class_method()
     var a = A.new()
     a.Bar()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Use a class private method from another class private method
   lines =<< trim END
@@ -3488,7 +3647,7 @@ def Test_private_class_method()
     var a = A.new()
     a.Bar()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Declare a class method and a class private method with the same name
   lines =<< trim END
@@ -3502,7 +3661,7 @@ def Test_private_class_method()
     endclass
     var a = A.new()
   END
-  v9.CheckScriptFailure(lines, 'E1355: Duplicate function: Foo')
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: Foo')
 
   # Try calling a class private method from another class
   lines =<< trim END
@@ -3521,7 +3680,7 @@ def Test_private_class_method()
     var b = B.new()
     assert_equal(1234, b.Foo())
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Call a private class method from a child class object method
   lines =<< trim END
@@ -3543,7 +3702,7 @@ def Test_private_class_method()
     var c = C.new()
     assert_equal(1234, c.Baz())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Call a private class method from a child class private class method
   lines =<< trim END
@@ -3564,7 +3723,7 @@ def Test_private_class_method()
     endclass
     assert_equal(1234, C.Baz())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Call a private class method from a child class object
   lines =<< trim END
@@ -3585,7 +3744,7 @@ def Test_private_class_method()
     var c = C.new()
     assert_equal(1234, C._Foo())
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1325: Method not found on class "C": _Foo')
 enddef
 
 " Test for an interface private object_method
@@ -3607,7 +3766,7 @@ def Test_interface_private_object_method()
     var a = A.new()
     assert_equal(1234, a.Bar())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Call an interface private class method (script context)
   lines =<< trim END
@@ -3623,7 +3782,7 @@ def Test_interface_private_object_method()
     var a = A.new()
     assert_equal(1234, a._Foo())
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Call an interface private class method (def context)
   lines =<< trim END
@@ -3642,7 +3801,7 @@ def Test_interface_private_object_method()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo()')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo()')
 
   # Implement an interface private object method as a private class method
   lines =<< trim END
@@ -3656,7 +3815,7 @@ def Test_interface_private_object_method()
       enddef
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1349: Function "_Foo" of interface "Intf" not implemented')
+  v9.CheckSourceFailure(lines, 'E1349: Function "_Foo" of interface "Intf" not implemented')
 enddef
 
 " Test for an interface private class method
@@ -3678,7 +3837,7 @@ def Test_interface_private_class_method()
     var a = A.new()
     assert_equal(1234, a.Bar())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Call an interface private class method (script context)
   lines =<< trim END
@@ -3693,7 +3852,7 @@ def Test_interface_private_class_method()
     endclass
     assert_equal(1234, A._Foo())
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo())')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo())')
 
   # Call an interface private class method (def context)
   lines =<< trim END
@@ -3711,7 +3870,7 @@ def Test_interface_private_class_method()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1366: Cannot access private method: _Foo())')
+  v9.CheckSourceFailure(lines, 'E1366: Cannot access private method: _Foo())')
 
   # Implement an interface private class method as a private object method
   lines =<< trim END
@@ -3725,7 +3884,7 @@ def Test_interface_private_class_method()
       enddef
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1349: Function "_Foo" of interface "Intf" not implemented')
+  v9.CheckSourceFailure(lines, 'E1349: Function "_Foo" of interface "Intf" not implemented')
 enddef
 
 " Test for using the return value of a class/object method as a function
@@ -3751,7 +3910,7 @@ def Test_objmethod_funcarg()
     var t = C.new()
     Baz(t)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   lines =<< trim END
     vim9script
@@ -3772,7 +3931,7 @@ def Test_objmethod_funcarg()
 
     Baz()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_static_inheritence()
@@ -3797,21 +3956,17 @@ def Test_static_inheritence()
 
     class B extends A
         def new()
-            _svar = 2
             this._mvar = 102
         enddef
     endclass
 
     class C extends B
         def new()
-            _svar = 3
             this._mvar = 103
         enddef
 
         def AccessPrivateStaticThroughClassName(): number
             assert_equal(1, A._svar)
-            assert_equal(2, B._svar)
-            assert_equal(3, C._svar)
             return 444
         enddef
     endclass
@@ -3823,14 +3978,14 @@ def Test_static_inheritence()
     assert_equal(102, ob.AccessObject())
     assert_equal(103, oc.AccessObject())
 
-    assert_equal(444, oc.AccessPrivateStaticThroughClassName())
+    assert_fails('echo oc.AccessPrivateStaticThroughClassName()', 'E1333: Cannot access private member: _svar')
 
     # verify object properly resolves to correct static
     assert_equal(1, oa.AccessStaticThroughObject())
-    assert_equal(2, ob.AccessStaticThroughObject())
-    assert_equal(3, oc.AccessStaticThroughObject())
+    assert_equal(1, ob.AccessStaticThroughObject())
+    assert_equal(1, oc.AccessStaticThroughObject())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for declaring duplicate object and class members
@@ -3843,7 +3998,7 @@ def Test_dup_member_variable()
       this.val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: val')
 
   # Duplicate private member variable
   lines =<< trim END
@@ -3853,7 +4008,7 @@ def Test_dup_member_variable()
       this._val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: _val')
 
   # Duplicate public member variable
   lines =<< trim END
@@ -3863,7 +4018,7 @@ def Test_dup_member_variable()
       public this.val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: val')
 
   # Duplicate private member variable
   lines =<< trim END
@@ -3873,7 +4028,7 @@ def Test_dup_member_variable()
       this._val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: _val')
 
   # Duplicate public and private member variable
   lines =<< trim END
@@ -3883,7 +4038,7 @@ def Test_dup_member_variable()
       public this.val = 10
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: val')
 
   # Duplicate class member variable
   lines =<< trim END
@@ -3893,7 +4048,7 @@ def Test_dup_member_variable()
       static _s: string = "def"
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _s')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: _s')
 
   # Duplicate public and private class member variable
   lines =<< trim END
@@ -3903,7 +4058,7 @@ def Test_dup_member_variable()
       static _s: string = "def"
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _s')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: _s')
 
   # Duplicate class and object member variable
   lines =<< trim END
@@ -3918,7 +4073,7 @@ def Test_dup_member_variable()
     assert_equal(10, C.val)
     assert_equal(20, c.val)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Duplicate object member variable in a derived class
   lines =<< trim END
@@ -3932,7 +4087,7 @@ def Test_dup_member_variable()
       this.val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: val')
 
   # Duplicate object private member variable in a derived class
   lines =<< trim END
@@ -3946,7 +4101,7 @@ def Test_dup_member_variable()
       this._val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: _val')
 
   # Duplicate object private member variable in a derived class
   lines =<< trim END
@@ -3960,7 +4115,7 @@ def Test_dup_member_variable()
       this._val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: _val')
 
   # Duplicate object member variable in a derived class
   lines =<< trim END
@@ -3974,63 +4129,7 @@ def Test_dup_member_variable()
       this.val = 20
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: val')
-
-  # Duplicate class member variable in a derived class
-  lines =<< trim END
-    vim9script
-    class A
-      static val = 10
-    endclass
-    class B extends A
-    endclass
-    class C extends B
-      static val = 20
-    endclass
-  END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: val')
-
-  # Duplicate private class member variable in a derived class
-  lines =<< trim END
-    vim9script
-    class A
-      static _val = 10
-    endclass
-    class B extends A
-    endclass
-    class C extends B
-      static _val = 20
-    endclass
-  END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _val')
-
-  # Duplicate private class member variable in a derived class
-  lines =<< trim END
-    vim9script
-    class A
-      static val = 10
-    endclass
-    class B extends A
-    endclass
-    class C extends B
-      static _val = 20
-    endclass
-  END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: _val')
-
-  # Duplicate class member variable in a derived class
-  lines =<< trim END
-    vim9script
-    class A
-      static _val = 10
-    endclass
-    class B extends A
-    endclass
-    class C extends B
-      static val = 20
-    endclass
-  END
-  v9.CheckScriptFailure(lines, 'E1369: Duplicate member: val')
+  v9.CheckSourceFailure(lines, 'E1369: Duplicate member: val')
 
   # Two member variables with a common prefix
   lines =<< trim END
@@ -4040,7 +4139,7 @@ def Test_dup_member_variable()
       public static svar: number
     endclass
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 def Test_interface_static_member_access()
@@ -4058,7 +4157,7 @@ def Test_interface_static_member_access()
     endclass
     C.new().F()
   END
-  v9.CheckScriptFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
+  v9.CheckSourceFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
 
   # In a class cannot write to interface static
   lines =<< trim END
@@ -4074,7 +4173,7 @@ def Test_interface_static_member_access()
     endclass
     C.new().F()
   END
-  v9.CheckScriptFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
+  v9.CheckSourceFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
 
   # In a def cannot read from interface static
   lines =<< trim END
@@ -4087,7 +4186,7 @@ def Test_interface_static_member_access()
     enddef
     F()
   END
-  v9.CheckScriptFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
+  v9.CheckSourceFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
 
   # In a def cannot write to interface static
   lines =<< trim END
@@ -4100,7 +4199,7 @@ def Test_interface_static_member_access()
     enddef
     F()
   END
-  v9.CheckScriptFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
+  v9.CheckSourceFailure(lines, 'E1409: Cannot directly access interface "I" static member "num"')
 
   # script level cannot read interface static
   lines =<< trim END
@@ -4111,7 +4210,7 @@ def Test_interface_static_member_access()
 
     var x = I.s_var1
   END
-  v9.CheckScriptFailure(lines, 'E1409: Cannot directly access interface "I" static member "s_var1"')
+  v9.CheckSourceFailure(lines, 'E1409: Cannot directly access interface "I" static member "s_var1"')
 
   # script level cannot write interface static
   lines =<< trim END
@@ -4122,7 +4221,7 @@ def Test_interface_static_member_access()
 
     I.s_var1 = 3
   END
-  v9.CheckScriptFailure(lines, 'E1409: Cannot directly access interface "I" static member "I.s_var1 = 3"')
+  v9.CheckSourceFailure(lines, 'E1409: Cannot directly access interface "I" static member "I.s_var1 = 3"')
 
 enddef
 
@@ -4158,7 +4257,7 @@ def Test_static_member_access_outside_class()
 
     assert_equal(11, F1())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for accessing a private member outside a class in a def function
@@ -4178,7 +4277,7 @@ def Test_private_member_access_outside_class()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1333: Cannot access private member: _val')
+  v9.CheckSourceFailure(lines, 'E1333: Cannot access private member: _val')
 
   # access a non-existing private object member variable
   lines =<< trim END
@@ -4192,7 +4291,7 @@ def Test_private_member_access_outside_class()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1089: Unknown variable: _a = 1')
+  v9.CheckSourceFailure(lines, 'E1089: Unknown variable: _a')
 
   # private static member variable
   lines =<< trim END
@@ -4206,7 +4305,7 @@ def Test_private_member_access_outside_class()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1326: Member not found on object "A": _val')
+  v9.CheckSourceFailure(lines, 'E1375: Class member "_val" accessible only using class "A"')
 
   # private static member variable
   lines =<< trim END
@@ -4220,8 +4319,7 @@ def Test_private_member_access_outside_class()
     enddef
     T()
   END
-  # TODO: wrong error, should be about private member
-  v9.CheckScriptFailure(lines, 'E1089: Unknown variable')
+  v9.CheckSourceFailure(lines, 'E1374: Class member "_val" accessible only inside class "A"')
 
   # private static class variable
   lines =<< trim END
@@ -4234,7 +4332,7 @@ def Test_private_member_access_outside_class()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1333: Cannot access private member: _val')
+  v9.CheckSourceFailure(lines, 'E1333: Cannot access private member: _val')
 
   # private static class variable
   lines =<< trim END
@@ -4247,7 +4345,7 @@ def Test_private_member_access_outside_class()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1333: Cannot access private member: _val')
+  v9.CheckSourceFailure(lines, 'E1333: Cannot access private member: _val')
 enddef
 
 " Test for changing the member access of an interface in a implementation class
@@ -4261,7 +4359,7 @@ def Test_change_interface_member_access()
       this.val = 10
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1367: Access level of member "val" of interface "A" is different')
+  v9.CheckSourceFailure(lines, 'E1367: Access level of member "val" of interface "A" is different')
 
   lines =<< trim END
     vim9script
@@ -4272,7 +4370,7 @@ def Test_change_interface_member_access()
       public this.val = 10
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1367: Access level of member "val" of interface "A" is different')
+  v9.CheckSourceFailure(lines, 'E1367: Access level of member "val" of interface "A" is different')
 enddef
 
 " Test for trying to change a readonly member from a def function
@@ -4288,7 +4386,7 @@ def Test_readonly_member_change_in_def_func()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E46: Cannot change read-only variable "val"')
+  v9.CheckSourceFailure(lines, 'E46: Cannot change read-only variable "val"')
 enddef
 
 " Test for reading and writing a class member from a def function
@@ -4312,7 +4410,7 @@ def Test_modify_class_member_from_def_function()
     enddef
     T()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for accessing a class member variable using an object
@@ -4337,7 +4435,7 @@ def Test_class_variable_access_using_object()
     enddef
     Foo()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Cannot read from a class variable using an object in script context
   lines =<< trim END
@@ -4350,7 +4448,7 @@ def Test_class_variable_access_using_object()
     var a = A.new()
     echo a.svar2
   END
-  v9.CheckScriptFailure(lines, 'E1326: Member not found on object "A": svar2')
+  v9.CheckSourceFailure(lines, 'E1375: Class member "svar2" accessible only using class "A"')
 
   # Cannot write to a class variable using an object in script context
   lines =<< trim END
@@ -4363,7 +4461,7 @@ def Test_class_variable_access_using_object()
     var a = A.new()
     a.svar2 = [2]
   END
-  v9.CheckScriptFailure(lines, 'E1334: Object member not found: svar2 = [2]')
+  v9.CheckSourceFailure(lines, 'E1375: Class member "svar2" accessible only using class "A"')
 
   # Cannot read from a class variable using an object in def method context
   lines =<< trim END
@@ -4379,7 +4477,7 @@ def Test_class_variable_access_using_object()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1326: Member not found on object "A": svar2')
+  v9.CheckSourceFailure(lines, 'E1375: Class member "svar2" accessible only using class "A"')
 
   # Cannot write to a class variable using an object in def method context
   lines =<< trim END
@@ -4395,7 +4493,7 @@ def Test_class_variable_access_using_object()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1089: Unknown variable: svar2 = [2]')
+  v9.CheckSourceFailure(lines, 'E1374: Class member "svar2" accessible only inside class "A"')
 enddef
 
 " Test for using a interface method using a child object
@@ -4431,7 +4529,7 @@ def Test_interface_method_from_child()
     T1(c)
     T2(c)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " Test for using an interface method using a child object when it is overridden
@@ -4472,7 +4570,7 @@ enddef
 "     T1(c)
 "     T2(c)
 "   END
-"   v9.CheckScriptSuccess(lines)
+"   v9.CheckSourceSuccess(lines)
 " enddef
 
 " Test for abstract methods
@@ -4498,7 +4596,7 @@ def Test_abstract_method()
     var b = B.new()
     assert_equal([10, 20, 30], [b.M1(), b.M2(), b.M3()])
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Don't define an abstract method
   lines =<< trim END
@@ -4509,7 +4607,7 @@ def Test_abstract_method()
     class B extends A
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1373: Abstract method "Foo" is not implemented')
+  v9.CheckSourceFailure(lines, 'E1373: Abstract method "Foo" is not implemented')
 
   # Use abstract method in a concrete class
   lines =<< trim END
@@ -4520,7 +4618,7 @@ def Test_abstract_method()
     class B extends A
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1372: Abstract method "abstract def Foo()" cannot be defined in a concrete class')
+  v9.CheckSourceFailure(lines, 'E1372: Abstract method "abstract def Foo()" cannot be defined in a concrete class')
 
   # Use abstract method in an interface
   lines =<< trim END
@@ -4531,7 +4629,7 @@ def Test_abstract_method()
     class B implements A
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1372: Abstract method "abstract def Foo()" cannot be defined in a concrete class')
+  v9.CheckSourceFailure(lines, 'E1372: Abstract method "abstract def Foo()" cannot be defined in a concrete class')
 
   # Abbreviate the "abstract" keyword
   lines =<< trim END
@@ -4540,7 +4638,7 @@ def Test_abstract_method()
       abs def Foo()
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1065: Command cannot be shortened: abs def Foo()')
+  v9.CheckSourceFailure(lines, 'E1065: Command cannot be shortened: abs def Foo()')
 
   # Use "abstract" with a member variable
   lines =<< trim END
@@ -4549,7 +4647,7 @@ def Test_abstract_method()
       abstract this.val = 10
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1371: Abstract must be followed by "def" or "static"')
+  v9.CheckSourceFailure(lines, 'E1371: Abstract must be followed by "def" or "static"')
 
   # Use a static abstract method
   lines =<< trim END
@@ -4564,7 +4662,7 @@ def Test_abstract_method()
     endclass
     assert_equal(4, B.Foo())
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Type mismatch between abstract method and concrete method
   lines =<< trim END
@@ -4578,7 +4676,7 @@ def Test_abstract_method()
       enddef
     endclass
   END
-  v9.CheckScriptFailure(lines, 'E1407: Method "Foo": type mismatch, expected func(string, number): list<number> but got func(number, string): list<string>')
+  v9.CheckSourceFailure(lines, 'E1407: Method "Foo": type mismatch, expected func(string, number): list<number> but got func(number, string): list<string>')
 
   # Use an abstract class to invoke an abstract method
   # FIXME: This should fail
@@ -4589,7 +4687,7 @@ def Test_abstract_method()
     endclass
     A.Foo()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # Invoke an abstract method from a def function
   lines =<< trim END
@@ -4608,7 +4706,31 @@ def Test_abstract_method()
     var b = B.new()
     Bar(b)
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
+enddef
+
+" Test for calling a class method from a subclass
+def Test_class_method_call_from_subclass()
+  # class method call from a subclass
+  var lines =<< trim END
+    vim9script
+
+    class A
+      static def Foo()
+        echo "foo"
+      enddef
+    endclass
+
+    class B extends A
+      def Bar()
+        Foo()
+      enddef
+    endclass
+
+    var b = B.new()
+    b.Bar()
+  END
+  v9.CheckSourceFailure(lines, 'E1374: Class member "Foo" accessible only inside class "A"')
 enddef
 
 " Test for calling a class method using an object in a def function context and
@@ -4638,7 +4760,7 @@ def Test_class_method_call_using_object()
     a.Bar()
     T()
   END
-  v9.CheckScriptSuccess(lines)
+  v9.CheckSourceSuccess(lines)
 
   # script context
   lines =<< trim END
@@ -4652,7 +4774,7 @@ def Test_class_method_call_using_object()
     var a = A.new()
     assert_equal('foo', a.Foo())
   END
-  v9.CheckScriptFailure(lines, 'E1325: Method not found on class "A": Foo()')
+  v9.CheckSourceFailure(lines, 'E1375: Class member "Foo" accessible only using class "A"')
 
   # def function context
   lines =<< trim END
@@ -4669,7 +4791,407 @@ def Test_class_method_call_using_object()
     enddef
     T()
   END
-  v9.CheckScriptFailure(lines, 'E1325: Method not found on class "A": Foo()')
+  v9.CheckSourceFailure(lines, 'E1375: Class member "Foo" accessible only using class "A"')
+enddef
+
+def Test_class_variable()
+  var lines =<< trim END
+    vim9script
+
+    class A
+      public static val: number = 10
+      static def ClassFunc()
+        assert_equal(10, val)
+      enddef
+      def ObjFunc()
+        assert_equal(10, val)
+      enddef
+    endclass
+
+    class B extends A
+    endclass
+
+    assert_equal(10, A.val)
+    A.ClassFunc()
+    var a = A.new()
+    a.ObjFunc()
+    var b = B.new()
+    b.ObjFunc()
+
+    def T1(a1: A)
+      a1.ObjFunc()
+      A.ClassFunc()
+    enddef
+    T1(b)
+
+    A.val = 20
+    assert_equal(20, A.val)
+  END
+  v9.CheckSourceSuccess(lines)
+
+  # Modifying a parent class variable from a child class method
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+
+    class B extends A
+      static def ClassFunc()
+        val = 20
+      enddef
+    endclass
+    B.ClassFunc()
+  END
+  v9.CheckSourceFailure(lines, 'E1374: Class member "val" accessible only inside class "A"')
+
+  # Reading a parent class variable from a child class method
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+
+    class B extends A
+      static def ClassFunc()
+        var i = val
+      enddef
+    endclass
+    B.ClassFunc()
+  END
+  v9.CheckSourceFailure(lines, 'E1374: Class member "val" accessible only inside class "A"')
+
+  # Modifying a parent class variable from a child object method
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+
+    class B extends A
+      def ObjFunc()
+        val = 20
+      enddef
+    endclass
+    var b = B.new()
+    b.ObjFunc()
+  END
+  v9.CheckSourceFailure(lines, 'E1374: Class member "val" accessible only inside class "A"')
+
+  # Reading a parent class variable from a child object method
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+
+    class B extends A
+      def ObjFunc()
+        var i = val
+      enddef
+    endclass
+    var b = B.new()
+    b.ObjFunc()
+  END
+  v9.CheckSourceFailure(lines, 'E1374: Class member "val" accessible only inside class "A"')
+
+  # Modifying a class variable using an object at script level
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+    var a = A.new()
+    a.val = 20
+  END
+  v9.CheckSourceFailure(lines, 'E1375: Class member "val" accessible only using class "A"')
+
+  # Reading a class variable using an object at script level
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+    var a = A.new()
+    var i = a.val
+  END
+  v9.CheckSourceFailure(lines, 'E1375: Class member "val" accessible only using class "A"')
+
+  # Modifying a class variable using an object at function level
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+
+    def T()
+      var a = A.new()
+      a.val = 20
+    enddef
+    T()
+  END
+  v9.CheckSourceFailure(lines, 'E1374: Class member "val" accessible only inside class "A"')
+
+  # Reading a class variable using an object at function level
+  lines =<< trim END
+    vim9script
+
+    class A
+      static val: number = 10
+    endclass
+    def T()
+      var a = A.new()
+      var i = a.val
+    enddef
+    T()
+  END
+  v9.CheckSourceFailure(lines, 'E1375: Class member "val" accessible only using class "A"')
+enddef
+
+" Test for using a duplicate class method and class variable in a child class
+def Test_dup_class_member()
+  # duplicate class variable, class method and overridden object method
+  var lines =<< trim END
+    vim9script
+    class A
+      static sval = 100
+      static def Check()
+        assert_equal(100, sval)
+      enddef
+      def GetVal(): number
+        return sval
+      enddef
+    endclass
+
+    class B extends A
+      static sval = 200
+      static def Check()
+        assert_equal(200, sval)
+      enddef
+      def GetVal(): number
+        return sval
+      enddef
+    endclass
+
+    def T1(aa: A): number
+      return aa.GetVal()
+    enddef
+
+    def T2(bb: B): number
+      return bb.GetVal()
+    enddef
+
+    assert_equal(100, A.sval)
+    assert_equal(200, B.sval)
+    var a = A.new()
+    assert_equal(100, a.GetVal())
+    var b = B.new()
+    assert_equal(200, b.GetVal())
+    assert_equal(200, T1(b))
+    assert_equal(200, T2(b))
+  END
+  v9.CheckSourceSuccess(lines)
+
+  # duplicate class variable and class method
+  lines =<< trim END
+    vim9script
+    class A
+      static sval = 100
+      static def Check()
+        assert_equal(100, sval)
+      enddef
+      def GetVal(): number
+        return sval
+      enddef
+    endclass
+
+    class B extends A
+      static sval = 200
+      static def Check()
+        assert_equal(200, sval)
+      enddef
+    endclass
+
+    def T1(aa: A): number
+      return aa.GetVal()
+    enddef
+
+    def T2(bb: B): number
+      return bb.GetVal()
+    enddef
+
+    assert_equal(100, A.sval)
+    assert_equal(200, B.sval)
+    var a = A.new()
+    assert_equal(100, a.GetVal())
+    var b = B.new()
+    assert_equal(100, b.GetVal())
+    assert_equal(100, T1(b))
+    assert_equal(100, T2(b))
+  END
+  v9.CheckSourceSuccess(lines)
+enddef
+
+" Test for calling an instance method using the class
+def Test_instance_method_call_using_class()
+  # Invoke an object method using a class in script context
+  var lines =<< trim END
+    vim9script
+    class A
+      def Foo()
+        echo "foo"
+      enddef
+    endclass
+    A.Foo()
+  END
+  v9.CheckSourceFailure(lines, 'E1376: Object member "Foo" accessible only using class "A" object')
+
+  # Invoke an object method using a class in def function context
+  lines =<< trim END
+    vim9script
+    class A
+      def Foo()
+        echo "foo"
+      enddef
+    endclass
+    def T()
+      A.Foo()
+    enddef
+    T()
+  END
+  v9.CheckSourceFailure(lines, 'E1376: Object member "Foo" accessible only using class "A" object')
+enddef
+
+" Test for duplicate class method and instance method
+def Test_dup_classmethod_objmethod()
+  # Duplicate instance method
+  var lines =<< trim END
+    vim9script
+    class A
+      static def Foo()
+      enddef
+      def Foo()
+      enddef
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: Foo')
+
+  # Duplicate private instance method
+  lines =<< trim END
+    vim9script
+    class A
+      static def Foo()
+      enddef
+      def _Foo()
+      enddef
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: _Foo')
+
+  # Duplicate class method
+  lines =<< trim END
+    vim9script
+    class A
+      def Foo()
+      enddef
+      static def Foo()
+      enddef
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: Foo')
+
+  # Duplicate private class method
+  lines =<< trim END
+    vim9script
+    class A
+      def Foo()
+      enddef
+      static def _Foo()
+      enddef
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: _Foo')
+
+  # Duplicate private class and object method
+  lines =<< trim END
+    vim9script
+    class A
+      def _Foo()
+      enddef
+      static def _Foo()
+      enddef
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1355: Duplicate function: _Foo')
+enddef
+
+" Test for an instance method access level comparison with parent instance
+" methods.
+def Test_instance_method_access_level()
+  # Private method in subclass
+  var lines =<< trim END
+    vim9script
+    class A
+      def Foo()
+      enddef
+    endclass
+    class B extends A
+    endclass
+    class C extends B
+      def _Foo()
+      enddef
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1378: Access level of method "_Foo" is different in class "A"')
+
+  # Public method in subclass
+  lines =<< trim END
+    vim9script
+    class A
+      def _Foo()
+      enddef
+    endclass
+    class B extends A
+    endclass
+    class C extends B
+      def Foo()
+      enddef
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1378: Access level of method "Foo" is different in class "A"')
+enddef
+
+def Test_extend_empty_class()
+  var lines =<< trim END
+    vim9script
+    class A
+    endclass
+    class B extends A
+    endclass
+    class C extends B
+      public static rw_class_var = 1
+      public this.rw_obj_var = 2
+      static def ClassMethod(): number
+        return 3
+      enddef
+      def ObjMethod(): number
+        return 4
+      enddef
+    endclass
+    assert_equal(1, C.rw_class_var)
+    assert_equal(3, C.ClassMethod())
+    var c = C.new()
+    assert_equal(2, c.rw_obj_var)
+    assert_equal(4, c.ObjMethod())
+  END
+  v9.CheckSourceSuccess(lines)
 enddef
 
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker
diff --git a/src/testdir/vim9.vim b/src/testdir/vim9.vim
index 5877a79ef..782809bde 100644
--- a/src/testdir/vim9.vim
+++ b/src/testdir/vim9.vim
@@ -110,6 +110,40 @@ export def CheckScriptSuccess(lines: list<string>)
   endtry
 enddef
 
+# :source a list of "lines" and check whether it fails with "error"
+export def CheckSourceFailure(lines: list<string>, error: string, lnum = -3)
+  new
+  setline(1, lines)
+  try
+    assert_fails('source', error, lines, lnum)
+  finally
+    bw!
+  endtry
+enddef
+
+# :source a list of "lines" and check whether it fails with the list of
+# "errors"
+export def CheckSourceFailureList(lines: list<string>, errors: list<string>, lnum = -3)
+  new
+  setline(1, lines)
+  try
+    assert_fails('source', errors, lines, lnum)
+  finally
+    bw!
+  endtry
+enddef
+
+# :source a list of "lines" and check whether it succeeds
+export def CheckSourceSuccess(lines: list<string>)
+  new
+  setline(1, lines)
+  try
+    :source
+  finally
+    bw!
+  endtry
+enddef
+
 export def CheckDefAndScriptSuccess(lines: list<string>)
   CheckDefSuccess(lines)
   CheckScriptSuccess(['vim9script'] + lines)
diff --git a/src/version.c b/src/version.c
index aaa50da4b..ba4be2780 100644
--- a/src/version.c
+++ b/src/version.c
@@ -699,6 +699,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1898,
 /**/
     1897,
 /**/
diff --git a/src/vim9class.c b/src/vim9class.c
index ccc381838..bf7d63295 100644
--- a/src/vim9class.c
+++ b/src/vim9class.c
@@ -322,63 +322,109 @@ validate_extends_class(char_u *extends_name, class_T **extends_clp)
 }
 
 /*
- * Check whether a class/object member variable in "classmembers_gap" /
- * "objmembers_gap" is a duplicate of a member in any of the extended parent
- * class lineage.  Returns TRUE if there are no duplicates.
+ * Check method names in the parent class lineage to make sure the access is
+ * the same for overridden methods.
+ */
+    static int
+validate_extends_methods(
+    garray_T	*objmethods_gap,
+    class_T	*extends_cl)
+{
+    class_T	*super = extends_cl;
+    int		method_count = objmethods_gap->ga_len;
+    ufunc_T	**cl_fp = (ufunc_T **)(objmethods_gap->ga_data);
+
+    while (super != NULL)
+    {
+	int extends_method_count = super->class_obj_method_count_child;
+	if (extends_method_count == 0)
+	{
+	    super = super->class_extends;
+	    continue;
+	}
+
+	ufunc_T **extends_methods = super->class_obj_methods;
+
+	for (int i = 0; i < extends_method_count; i++)
+	{
+	    char_u  *pstr = extends_methods[i]->uf_name;
+	    int	    extends_private = (*pstr == '_');
+	    if (extends_private)
+		pstr++;
+
+	    for (int j = 0; j < method_count; j++)
+	    {
+		char_u  *qstr = cl_fp[j]->uf_name;
+		int	priv_method = (*qstr == '_');
+		if (priv_method)
+		    qstr++;
+		if (STRCMP(pstr, qstr) == 0 && priv_method != extends_private)
+		{
+		    // Method access is different between the super class and
+		    // the subclass
+		    semsg(_(e_method_str_of_class_str_has_different_access),
+			    cl_fp[j]->uf_name, super->class_name);
+		    return FALSE;
+		}
+	    }
+	}
+	super = super->class_extends;
+    }
+
+    return TRUE;
+}
+
+/*
+ * Check whether a object member variable in "objmembers_gap" is a duplicate of
+ * a member in any of the extended parent class lineage.  Returns TRUE if there
+ * are no duplicates.
  */
     static int
 validate_extends_members(
-    garray_T	*classmembers_gap,
     garray_T	*objmembers_gap,
     class_T	*extends_cl)
 {
-    for (int loop = 1; loop <= 2; ++loop)
-    {
-	// loop == 1: check class members
-	// loop == 2: check object members
-	int member_count = loop == 1 ? classmembers_gap->ga_len
-						: objmembers_gap->ga_len;
-	if (member_count == 0)
-	    continue;
-	ocmember_T *members = (ocmember_T *)(loop == 1
-						? classmembers_gap->ga_data
-						: objmembers_gap->ga_data);
+    // loop == 1: check class members
+    // loop == 2: check object members
+    int member_count = objmembers_gap->ga_len;
+    if (member_count == 0)
+	return TRUE;
 
-	// Validate each member variable
-	for (int c_i = 0; c_i < member_count; c_i++)
-	{
-	    class_T	*p_cl = extends_cl;
-	    ocmember_T	*c_m = members + c_i;
-	    char_u	*pstr = (*c_m->ocm_name == '_')
+    ocmember_T *members = (ocmember_T *)(objmembers_gap->ga_data);
+
+    // Validate each member variable
+    for (int c_i = 0; c_i < member_count; c_i++)
+    {
+	class_T	    *p_cl = extends_cl;
+	ocmember_T  *c_m = members + c_i;
+	char_u	    *pstr = (*c_m->ocm_name == '_')
 					? c_m->ocm_name + 1 : c_m->ocm_name;
 
-	    // Check in all the parent classes in the lineage
-	    while (p_cl != NULL)
+	// Check in all the parent classes in the lineage
+	while (p_cl != NULL)
+	{
+	    int p_member_count = p_cl->class_obj_member_count;
+	    if (p_member_count == 0)
 	    {
-		int p_member_count = loop == 1
-					? p_cl->class_class_member_count
-					: p_cl->class_obj_member_count;
-		if (p_member_count == 0)
-		    continue;
-		ocmember_T *p_members = (loop == 1
-					? p_cl->class_class_members
-					: p_cl->class_obj_members);
-
-		// Compare against all the members in the parent class
-		for (int p_i = 0; p_i < p_member_count; p_i++)
-		{
-		    ocmember_T	*p_m = p_members + p_i;
-		    char_u	*qstr = (*p_m->ocm_name == '_')
-					? p_m->ocm_name + 1 : p_m->ocm_name;
-		    if (STRCMP(pstr, qstr) == 0)
-		    {
-			semsg(_(e_duplicate_member_str), c_m->ocm_name);
-			return FALSE;
-		    }
-		}
-
 		p_cl = p_cl->class_extends;
+		continue;
 	    }
+	    ocmember_T *p_members = p_cl->class_obj_members;
+
+	    // Compare against all the members in the parent class
+	    for (int p_i = 0; p_i < p_member_count; p_i++)
+	    {
+		ocmember_T	*p_m = p_members + p_i;
+		char_u	*qstr = (*p_m->ocm_name == '_')
+		    ? p_m->ocm_name + 1 : p_m->ocm_name;
+		if (STRCMP(pstr, qstr) == 0)
+		{
+		    semsg(_(e_duplicate_member_str), c_m->ocm_name);
+		    return FALSE;
+		}
+	    }
+
+	    p_cl = p_cl->class_extends;
 	}
     }
 
@@ -391,7 +437,7 @@ validate_extends_members(
  * implemented.
  */
     static int
-validate_extends_methods(
+validate_abstract_class_methods(
     garray_T	*classmethods_gap,
     garray_T	*objmethods_gap,
     class_T	*extends_cl)
@@ -707,18 +753,26 @@ is_duplicate_member(garray_T *mgap, char_u *varname, char_u *varname_end)
  * Returns TRUE if the method "name" is already defined.
  */
     static int
-is_duplicate_method(garray_T *fgap, char_u *name)
+is_duplicate_method(
+    garray_T	*classmethods_gap,
+    garray_T	*objmethods_gap,
+    char_u	*name)
 {
     char_u *pstr = (*name == '_') ? name + 1 : name;
 
-    for (int i = 0; i < fgap->ga_len; ++i)
+    // loop 1: class methods, loop 2: object methods
+    for (int loop = 1; loop <= 2; loop++)
     {
-	char_u	*n = ((ufunc_T **)fgap->ga_data)[i]->uf_name;
-	char_u	*qstr = *n == '_' ? n + 1 : n;
-	if (STRCMP(pstr, qstr) == 0)
+	garray_T *fgap = (loop == 1) ? classmethods_gap : objmethods_gap;
+	for (int i = 0; i < fgap->ga_len; ++i)
 	{
-	    semsg(_(e_duplicate_function_str), name);
-	    return TRUE;
+	    char_u	*n = ((ufunc_T **)fgap->ga_data)[i]->uf_name;
+	    char_u	*qstr = *n == '_' ? n + 1 : n;
+	    if (STRCMP(pstr, qstr) == 0)
+	    {
+		semsg(_(e_duplicate_function_str), name);
+		return TRUE;
+	    }
 	}
     }
 
@@ -882,7 +936,7 @@ add_lookup_tables(class_T *cl, class_T *extends_cl, garray_T *objmethods_gap)
 	    return FAIL;
     }
 
-    // Update the lookup table for the extended class, if nay
+    // Update the lookup table for the extended class, if any
     if (extends_cl != NULL)
     {
 	class_T		*pclass = extends_cl;
@@ -1017,9 +1071,10 @@ add_classfuncs_objmethods(
 
 	int parent_count = 0;
 	if (extends_cl != NULL)
-	    // Include functions from the parent.
+	    // Include object methods from the parent.
+	    // Don't include the parent class methods.
 	    parent_count = loop == 1
-				? extends_cl->class_class_function_count
+				? 0
 				: extends_cl->class_obj_method_count;
 
 	*fcount = parent_count + gap->ga_len;
@@ -1087,6 +1142,8 @@ add_classfuncs_objmethods(
 	{
 	    ufunc_T *fp = (*fup)[i];
 	    fp->uf_class = cl;
+	    if (i < gap->ga_len)
+		fp->uf_defclass = cl;
 	    if (loop == 2)
 		fp->uf_flags |= FC_OBJECT;
 	}
@@ -1443,16 +1500,16 @@ early_ret:
 		    break;
 		}
 
-		garray_T *fgap = has_static || is_new
-					       ? &classfunctions : &objmethods;
 		// Check the name isn't used already.
-		if (is_duplicate_method(fgap, name))
+		if (is_duplicate_method(&classfunctions, &objmethods, name))
 		{
 		    success = FALSE;
 		    func_clear_free(uf, FALSE);
 		    break;
 		}
 
+		garray_T *fgap = has_static || is_new
+					       ? &classfunctions : &objmethods;
 		if (ga_grow(fgap, 1) == OK)
 		{
 		    if (is_new)
@@ -1517,19 +1574,23 @@ early_ret:
 	success = validate_extends_class(extends, &extends_cl);
     VIM_CLEAR(extends);
 
-    // Check the new class members and object members are not duplicates of the
-    // members in the extended class lineage.
+    // Check the new object methods to make sure their access (public or
+    // private) is the same as that in the extended class lineage.
     if (success && extends_cl != NULL)
-	success = validate_extends_members(&classmembers, &objmembers,
-								extends_cl);
+	success = validate_extends_methods(&objmethods, extends_cl);
+
+    // Check the new class and object variables are not duplicates of the
+    // variables in the extended class lineage.
+    if (success && extends_cl != NULL)
+	success = validate_extends_members(&objmembers, extends_cl);
 
     // When extending an abstract class, make sure all the abstract methods in
     // the parent class are implemented.  If the current class is an abstract
     // class, then there is no need for this check.
     if (success && !is_abstract && extends_cl != NULL
 				&& (extends_cl->class_flags & CLASS_ABSTRACT))
-	success = validate_extends_methods(&classfunctions, &objmethods,
-								extends_cl);
+	success = validate_abstract_class_methods(&classfunctions,
+						&objmethods, extends_cl);
 
     class_T **intf_classes = NULL;
 
@@ -1572,12 +1633,10 @@ early_ret:
 	    extends_cl->class_flags |= CLASS_EXTENDED;
 	}
 
-	// Add class and object members to "cl".
+	// Add class and object variables to "cl".
 	if (add_members_to_class(&classmembers,
-				 extends_cl == NULL ? NULL
-					     : extends_cl->class_class_members,
-				 extends_cl == NULL ? 0
-					: extends_cl->class_class_member_count,
+				 NULL,
+				 0,
 				 &cl->class_class_members,
 				 &cl->class_class_member_count) == FAIL
 		|| add_members_to_class(&objmembers,
@@ -1756,7 +1815,21 @@ class_member_type(
 								member_idx);
     if (m == NULL)
     {
-	semsg(_(e_unknown_variable_str), name);
+	char_u *varname = vim_strnsave(name, len);
+	if (varname != NULL)
+	{
+	    if (is_object && class_member_idx(cl, name, len) >= 0)
+		// A class variable with this name is present
+		semsg(_(e_class_member_str_accessible_only_inside_class_str),
+			varname, cl->class_name);
+	    else if (!is_object && object_member_idx(cl, name, len) >= 0)
+		// An instance variable with this name is present
+		semsg(_(e_object_member_str_accessible_only_using_object_str),
+			varname, cl->class_name);
+	    else
+		semsg(_(e_unknown_variable_str), varname);
+	}
+	vim_free(varname);
 	return &t_any;
     }
 
@@ -1887,8 +1960,7 @@ class_object_index(
 	fp = method_lookup(cl, rettv->v_type, name, len, NULL);
 	if (fp == NULL)
 	{
-	    semsg(_(e_method_not_found_on_class_str_str), cl->class_name,
-		    name);
+	    method_not_found_msg(cl, rettv->v_type, name, len);
 	    return FAIL;
 	}
 
@@ -1951,7 +2023,7 @@ class_object_index(
 	    return OK;
 	}
 
-	semsg(_(e_member_not_found_on_object_str_str), cl->class_name, name);
+	member_not_found_msg(cl, VAR_OBJECT, name, len);
     }
 
     else if (rettv->v_type == VAR_CLASS)
@@ -1962,7 +2034,7 @@ class_object_index(
 	ocmember_T *m = class_member_lookup(cl, name, len, &m_idx);
 	if (m == NULL)
 	{
-	    semsg(_(e_member_not_found_on_class_str_str), cl->class_name, name);
+	    member_not_found_msg(cl, VAR_CLASS, name, len);
 	    return FAIL;
 	}
 
@@ -2029,7 +2101,7 @@ fail_after_eval:
 }
 
 /*
- * Returns the index of class member variable "name" in the class "cl".
+ * Returns the index of class variable "name" in the class "cl".
  * Returns -1, if the variable is not found.
  * If "namelen" is zero, then it is assumed that "name" is NUL terminated.
  */
@@ -2497,6 +2569,68 @@ object_free_nonref(int copyID)
     return did_free;
 }
 
+/*
+ * Echo a class or object method not found message.
+ */
+    void
+method_not_found_msg(class_T *cl, vartype_T v_type, char_u *name, size_t len)
+{
+    char_u *method_name = vim_strnsave(name, len);
+    if ((v_type == VAR_OBJECT)
+	    && (class_method_idx(cl, name, len) >= 0))
+    {
+	// If this is a class method, then give a different error
+	if (*name == '_')
+	    semsg(_(e_cannot_access_private_method_str), method_name);
+	else
+	    semsg(_(e_class_member_str_accessible_only_using_class_str),
+		    method_name, cl->class_name);
+    }
+    else if ((v_type == VAR_CLASS)
+	    && (object_method_idx(cl, name, len) >= 0))
+    {
+	// If this is an object method, then give a different error
+	if (*name == '_')
+	    semsg(_(e_cannot_access_private_method_str), method_name);
+	else
+	    semsg(_(e_object_member_str_accessible_only_using_object_str),
+		    method_name, cl->class_name);
+    }
+    else
+	semsg(_(e_method_not_found_on_class_str_str), cl->class_name,
+		method_name);
+    vim_free(method_name);
+}
+
+/*
+ * Echo a class or object member not found message.
+ */
+    void
+member_not_found_msg(class_T *cl, vartype_T v_type, char_u *name, size_t len)
+{
+    char_u *varname = len ? vim_strnsave(name, len) : vim_strsave(name);
+
+    if (v_type == VAR_OBJECT)
+    {
+	if (class_member_idx(cl, name, len) >= 0)
+	    semsg(_(e_class_member_str_accessible_only_using_class_str),
+		    varname, cl->class_name);
+	else
+	    semsg(_(e_member_not_found_on_object_str_str), cl->class_name,
+		    varname);
+    }
+    else
+    {
+	if (object_member_idx(cl, name, len) >= 0)
+	    semsg(_(e_object_member_str_accessible_only_using_object_str),
+		    varname, cl->class_name);
+	else
+	    semsg(_(e_class_member_str_not_found_in_class_str),
+		    varname, cl->class_name);
+    }
+    vim_free(varname);
+}
+
 /*
  * Return TRUE when the class "cl", its base class or one of the implemented
  * interfaces matches the class "other_cl".
diff --git a/src/vim9compile.c b/src/vim9compile.c
index cc4aa4638..7de1b6253 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -332,24 +332,42 @@ script_var_exists(char_u *name, size_t len, cctx_T *cctx, cstack_T *cstack)
 }
 
 /*
- * If "name[len]" is a class method in cctx->ctx_ufunc->uf_class return the
- * class method index.
+ * Returns the index of a class method or class variable with name "name"
+ * accessible in the currently compiled function.
  * If "cl_ret" is not NULL set it to the class.
  * Otherwise return -1.
  */
-    int
-cctx_class_method_idx(
+    static int
+cctx_class_midx(
     cctx_T  *cctx,
+    int	    is_method,
     char_u  *name,
     size_t  len,
     class_T **cl_ret)
 {
     if (cctx == NULL || cctx->ctx_ufunc == NULL
-	    || cctx->ctx_ufunc->uf_class == NULL)
+	    || cctx->ctx_ufunc->uf_class == NULL
+	    || cctx->ctx_ufunc->uf_defclass == NULL)
 	return -1;
 
-    class_T *cl = cctx->ctx_ufunc->uf_class;
-    int m_idx = class_method_idx(cl, name, len);
+    // Search for the class method or variable in the class where the calling
+    // function is defined.
+    class_T *cl = cctx->ctx_ufunc->uf_defclass;
+    int m_idx = is_method ? class_method_idx(cl, name, len)
+					: class_member_idx(cl, name, len);
+    if (m_idx < 0)
+    {
+	cl = cl->class_extends;
+	while (cl != NULL)
+	{
+	    m_idx = is_method ? class_method_idx(cl, name, len)
+					: class_member_idx(cl, name, len);
+	    if (m_idx >= 0)
+		break;
+	    cl = cl->class_extends;
+	}
+    }
+
     if (m_idx >= 0)
     {
 	if (cl_ret != NULL)
@@ -360,10 +378,24 @@ cctx_class_method_idx(
 }
 
 /*
- * If "name[len]" is a class member in cctx->ctx_ufunc->uf_class return the
- * class member variable index.
- * If "cl_ret" is not NULL set it to the class.
- * Otherwise return -1;
+ * Returns the index of a class method with name "name" accessible in the
+ * currently compiled function.  Returns -1 if not found.  The class where the
+ * method is defined is returned in "cl_ret".
+ */
+    int
+cctx_class_method_idx(
+    cctx_T  *cctx,
+    char_u  *name,
+    size_t  len,
+    class_T **cl_ret)
+{
+    return cctx_class_midx(cctx, TRUE, name, len, cl_ret);
+}
+
+/*
+ * Returns the index of a class variable with name "name" accessible in the
+ * currently compiled function.  Returns -1 if not found.  The class where the
+ * variable is defined is returned in "cl_ret".
  */
     int
 cctx_class_member_idx(
@@ -372,19 +404,7 @@ cctx_class_member_idx(
     size_t  len,
     class_T **cl_ret)
 {
-    if (cctx == NULL || cctx->ctx_ufunc == NULL
-	    || cctx->ctx_ufunc->uf_class == NULL)
-	return -1;
-
-    class_T *cl = cctx->ctx_ufunc->uf_class;
-    int m_idx = class_member_idx(cl, name, len);
-    if (m_idx >= 0)
-    {
-	if (cl_ret != NULL)
-	    *cl_ret = cl;
-    }
-
-    return m_idx;
+    return cctx_class_midx(cctx, FALSE, name, len, cl_ret);
 }
 
 /*
@@ -1639,6 +1659,8 @@ compile_lhs(
 	}
 	else
 	{
+	    class_T	*defcl;
+
 	    // No specific kind of variable recognized, just a name.
 	    if (check_reserved_name(lhs->lhs_name, lhs->lhs_has_index
 						&& *var_end == '.') == FAIL)
@@ -1681,8 +1703,16 @@ compile_lhs(
 		}
 	    }
 	    else if ((lhs->lhs_classmember_idx = cctx_class_member_idx(
-			    cctx, var_start, lhs->lhs_varlen, NULL)) >= 0)
+			    cctx, var_start, lhs->lhs_varlen, &defcl)) >= 0)
 	    {
+		if (cctx->ctx_ufunc->uf_defclass != defcl)
+		{
+		    // A class variable can be accessed without the class name
+		    // only inside a class.
+		    semsg(_(e_class_member_str_accessible_only_inside_class_str),
+			    lhs->lhs_name, defcl->class_name);
+		    return FAIL;
+		}
 		if (is_decl)
 		{
 		    semsg(_(e_variable_already_declared_in_class_str),
@@ -1918,10 +1948,10 @@ compile_lhs(
 
 	int use_class = lhs->lhs_type != NULL
 			    && (lhs->lhs_type->tt_type == VAR_CLASS
-				       || lhs->lhs_type->tt_type == VAR_OBJECT);
+				    || lhs->lhs_type->tt_type == VAR_OBJECT);
 	if (lhs->lhs_type == NULL
 		|| (use_class ? lhs->lhs_type->tt_class == NULL
-					   : lhs->lhs_type->tt_member == NULL))
+		    : lhs->lhs_type->tt_member == NULL))
 	{
 	    lhs->lhs_member_type = &t_any;
 	}
@@ -1930,9 +1960,10 @@ compile_lhs(
 	    // for an object or class member get the type of the member
 	    class_T	*cl = lhs->lhs_type->tt_class;
 	    ocmember_T	*m;
+	    int		is_object = lhs->lhs_type->tt_type == VAR_OBJECT;
 
 	    lhs->lhs_member_type = class_member_type(cl,
-					lhs->lhs_type->tt_type == VAR_OBJECT,
+					is_object,
 					after + 1, lhs->lhs_end,
 					&lhs->lhs_member_idx, &m);
 	    if (lhs->lhs_member_idx < 0)
@@ -1946,7 +1977,11 @@ compile_lhs(
 	    }
 	    // If it is private member variable, then accessing it outside the
 	    // class is not allowed.
-	    if ((m->ocm_access != VIM_ACCESS_ALL) && !inside_class(cctx, cl))
+	    // If it is a read only class variable, then it can be modified
+	    // only inside the class where it is defined.
+	    if ((m->ocm_access != VIM_ACCESS_ALL) &&
+		    ((is_object && !inside_class(cctx, cl))
+		     || (!is_object && cctx->ctx_ufunc->uf_class != cl)))
 	    {
 		char *msg = (m->ocm_access == VIM_ACCESS_PRIVATE)
 				? e_cannot_access_private_member_str
diff --git a/src/vim9execute.c b/src/vim9execute.c
index f8e267641..7c61ff418 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -2172,8 +2172,7 @@ execute_storeindex(isn_T *iptr, ectx_T *ectx)
 	    {
 		if (*member == '_')
 		{
-		    semsg(_(e_cannot_access_private_member_str),
-			    m->ocm_name);
+		    semsg(_(e_cannot_access_private_member_str), m->ocm_name);
 		    status = FAIL;
 		}
 
@@ -2181,8 +2180,7 @@ execute_storeindex(isn_T *iptr, ectx_T *ectx)
 	    }
 	    else
 	    {
-		semsg(_(e_member_not_found_on_object_str_str),
-						       cl->class_name, member);
+		member_not_found_msg(cl, VAR_OBJECT, member, 0);
 		status = FAIL;
 	    }
 	}
diff --git a/src/vim9expr.c b/src/vim9expr.c
index 120a60627..a158f31ae 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -367,12 +367,19 @@ compile_class_object_index(cctx_T *cctx, char_u **arg, type_T *type)
 	}
 	if (ufunc == NULL)
 	{
-	    // TODO: different error for object method?
-	    semsg(_(e_method_not_found_on_class_str_str), cl->class_name, name);
+	    method_not_found_msg(cl, type->tt_type, name, len);
 	    return FAIL;
 	}
 
-	if (*ufunc->uf_name == '_' && !inside_class_hierarchy(cctx, cl))
+	// A private object method can be used only inside the class where it
+	// is defined or in one of the child classes.
+	// A private class method can be used only in the class where it is
+	// defined.
+	if (*ufunc->uf_name == '_' &&
+		((type->tt_type == VAR_OBJECT
+		  && !inside_class_hierarchy(cctx, cl))
+		 || (type->tt_type == VAR_CLASS
+		     && cctx->ctx_ufunc->uf_class != cl)))
 	{
 	    semsg(_(e_cannot_access_private_method_str), name);
 	    return FAIL;
@@ -422,7 +429,7 @@ compile_class_object_index(cctx_T *cctx, char_u **arg, type_T *type)
 	    return generate_FUNCREF(cctx, fp, NULL, 0, NULL);
 	}
 
-	semsg(_(e_member_not_found_on_object_str_str), cl->class_name, name);
+	member_not_found_msg(cl, VAR_OBJECT, name, len);
     }
     else
     {
@@ -438,7 +445,9 @@ compile_class_object_index(cctx_T *cctx, char_u **arg, type_T *type)
 			cl->class_name, m->ocm_name);
 		return FAIL;
 	    }
-	    if (*name == '_' && !inside_class(cctx, cl))
+	    // A private class variable can be accessed only in the class where
+	    // it is defined.
+	    if (*name == '_' && cctx->ctx_ufunc->uf_class != cl)
 	    {
 		semsg(_(e_cannot_access_private_member_str), m->ocm_name);
 		return FAIL;
@@ -447,7 +456,7 @@ compile_class_object_index(cctx_T *cctx, char_u **arg, type_T *type)
 	    *arg = name_end;
 	    return generate_CLASSMEMBER(cctx, TRUE, cl, idx);
 	}
-	semsg(_(e_class_member_not_found_str), name);
+	member_not_found_msg(cl, VAR_CLASS, name, len);
     }
 
     return FAIL;
@@ -762,9 +771,17 @@ compile_load(
 	    }
 	    else if ((idx = cctx_class_member_idx(cctx, *arg, len, &cl)) >= 0)
 	    {
-		// Referencing a class member without the class name.  Infer
-		// the class from the def function context.
-		res = generate_CLASSMEMBER(cctx, TRUE, cl, idx);
+		// Referencing a class variable without the class name.
+		// A class variable can be referenced without the class name
+		// only in the class where the function is defined.
+		if (cctx->ctx_ufunc->uf_defclass == cl)
+		    res = generate_CLASSMEMBER(cctx, TRUE, cl, idx);
+		else
+		{
+		    semsg(_(e_class_member_str_accessible_only_inside_class_str),
+			    name, cl->class_name);
+		    res = FAIL;
+		}
 	    }
 	    else
 	    {
@@ -1130,12 +1147,23 @@ compile_call(
 	}
 	else if ((mi = cctx_class_method_idx(cctx, name, varlen, &cl)) >= 0)
 	{
-	    // Class method invocation without the class name.  The
-	    // generate_CALL() function expects the class type at the top of
-	    // the stack.  So push the class type to the stack.
-	    push_type_stack(cctx, &t_class);
-	    res = generate_CALL(cctx, cl->class_class_functions[mi], NULL, 0,
-							type, argcount);
+	    // Class method invocation without the class name.
+	    // A class method can be referenced without the class name only in
+	    // the class where the function is defined.
+	    if (cctx->ctx_ufunc->uf_defclass == cl)
+	    {
+		// The generate_CALL() function expects the class type at the
+		// top of the stack.  So push the class type to the stack.
+		push_type_stack(cctx, &t_class);
+		res = generate_CALL(cctx, cl->class_class_functions[mi], NULL,
+							0, type, argcount);
+	    }
+	    else
+	    {
+		semsg(_(e_class_member_str_accessible_only_inside_class_str),
+			name, cl->class_name);
+		res = FAIL;
+	    }
 	    goto theend;
 	}
     }