big updates: tests, bug fixed, documentation. oh my

encoding/xml/xml_test.go

@@ -0,0 +1,113 @@
+package xml
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+type testStruct struct {
+	XMLName struct{} `xml:"root"`
+	Name    string   `xml:"name"`
+	Value   int      `xml:"value"`
+}
+
+func TestEncoder(t *testing.T) {
+	t.Run("successful encode", func(t *testing.T) {
+		var buf bytes.Buffer
+		data := testStruct{Name: "test", Value: 42}
+
+		err := Encoder(&buf, data)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+
+		result := buf.String()
+		if !strings.Contains(result, "<name>test</name>") {
+			t.Errorf("expected result to contain '<name>test</name>', got %q", result)
+		}
+		if !strings.Contains(result, "<value>42</value>") {
+			t.Errorf("expected result to contain '<value>42</value>', got %q", result)
+		}
+	})
+
+	t.Run("encode slice", func(t *testing.T) {
+		type Item struct {
+			Value int `xml:"value"`
+		}
+		var buf bytes.Buffer
+		data := []Item{{Value: 1}, {Value: 2}}
+
+		err := Encoder(&buf, data)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+
+		result := buf.String()
+		if !strings.Contains(result, "<value>1</value>") {
+			t.Error("expected result to contain first item")
+		}
+		if !strings.Contains(result, "<value>2</value>") {
+			t.Error("expected result to contain second item")
+		}
+	})
+}
+
+func TestDecoder(t *testing.T) {
+	t.Run("successful decode", func(t *testing.T) {
+		input := `<root><name>test</name><value>42</value></root>`
+		reader := strings.NewReader(input)
+
+		var result testStruct
+		err := Decoder(reader, &result)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+
+		if result.Name != "test" {
+			t.Errorf("expected name 'test', got %q", result.Name)
+		}
+		if result.Value != 42 {
+			t.Errorf("expected value 42, got %d", result.Value)
+		}
+	})
+
+	t.Run("decode empty XML", func(t *testing.T) {
+		input := `<root></root>`
+		reader := strings.NewReader(input)
+
+		var result testStruct
+		err := Decoder(reader, &result)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+
+		if result.Name != "" {
+			t.Errorf("expected empty name, got %q", result.Name)
+		}
+		if result.Value != 0 {
+			t.Errorf("expected zero value, got %d", result.Value)
+		}
+	})
+
+	t.Run("decode invalid XML", func(t *testing.T) {
+		input := `<invalid><unclosed>`
+		reader := strings.NewReader(input)
+
+		var result testStruct
+		err := Decoder(reader, &result)
+		if err == nil {
+			t.Fatal("expected error for invalid XML, got nil")
+		}
+	})
+
+	t.Run("decode empty input", func(t *testing.T) {
+		reader := strings.NewReader("")
+
+		var result testStruct
+		err := Decoder(reader, &result)
+		if err == nil {
+			t.Fatal("expected error for empty input, got nil")
+		}
+	})
+}