patch 9.1.0415: Some functions are not tested

Problem:  Some functions are not tested
Solution: Add a few more tests, fix a few minor problems
          (Yegappan Lakshmanan)

closes: #14789

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_vim9_expr.vim

@@ -309,6 +309,9 @@ def Test_expr2()
         g:vals = [1]
       endif
       assert_equal([1], g:vals)
+
+      # string interpolation with ||
+      assert_equal('true', $"{0 || 1}")
   END
   v9.CheckDefAndScriptSuccess(lines)
 
@@ -415,6 +418,7 @@ def Test_expr2_fails()
   v9.CheckDefExecAndScriptFailure(['var x = 3', 'if x', 'endif'], 'E1023:', 2)
 
   v9.CheckDefAndScriptFailure(["var x = [] || false"], ['E1012: Type mismatch; expected bool but got list<any>', 'E745:'], 1)
+  v9.CheckDefAndScriptFailure(["var x = $'{false || []}'"], ['E1012: Type mismatch; expected bool but got list<any>', 'E745:'], 1)
 
   var lines =<< trim END
     vim9script
@@ -475,6 +479,9 @@ def Test_expr3()
         failed = true
       endif
       assert_false(failed)
+
+      # string interpolation with &&
+      assert_equal('false', $"{1 && 0}")
   END
   v9.CheckDefAndScriptSuccess(lines)
 enddef
@@ -574,6 +581,8 @@ def Test_expr3_fails()
       echo true && s
   END
   v9.CheckDefAndScriptFailure(lines, ['E1012: Type mismatch; expected bool but got string', 'E1135: Using a String as a Bool: "asdf"'])
+
+  v9.CheckDefAndScriptFailure(["var x = $'{true && []}'"], ['E1012: Type mismatch; expected bool but got list<any>', 'E745:'], 1)
 enddef
 
 " global variables to use for tests with the "any" type
@@ -2152,6 +2161,7 @@ def Test_expr9_blob()
   v9.CheckDefAndScriptSuccess(lines)
 
   v9.CheckDefAndScriptFailure(["var x = 0z123"], 'E973:', 1)
+  v9.CheckDefAndScriptFailure(["var x = null_blox"], ['E1001:', 'E121:'], 1)
 enddef
 
 def Test_expr9_string()