fix(validation): correct CustomValidator and strutils.Parser handling, add tests

internal/serialization/validation_struct_test.go

@@ -0,0 +1,66 @@
+package serialization
+
+import (
+	"reflect"
+	"testing"
+
+	gperr "github.com/yusing/goutils/errs"
+)
+
+type CustomValidatingStruct struct {
+	Value string
+}
+
+func (c CustomValidatingStruct) Validate() gperr.Error {
+	if c.Value == "" {
+		return gperr.New("value cannot be empty")
+	}
+	if len(c.Value) < 3 {
+		return gperr.New("value must be at least 3 characters")
+	}
+	return nil
+}
+
+func TestValidateWithCustomValidator_Struct(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   CustomValidatingStruct
+		wantErr bool
+	}{
+		{"valid custom validating struct", CustomValidatingStruct{Value: "hello"}, false},
+		{"invalid custom validating struct - empty", CustomValidatingStruct{Value: ""}, true},
+		{"invalid custom validating struct - too short", CustomValidatingStruct{Value: "hi"}, true},
+		{"valid custom validating struct - minimum length", CustomValidatingStruct{Value: "abc"}, false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := ValidateWithCustomValidator(reflect.ValueOf(tt.input))
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ValidateWithCustomValidator() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestValidateWithCustomValidator_CustomValidatingStructPointer(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   *CustomValidatingStruct
+		wantErr bool
+	}{
+		{"valid custom validating struct pointer", &CustomValidatingStruct{Value: "hello"}, false},
+		{"nil custom validating struct pointer", nil, true},
+		{"invalid custom validating struct pointer - empty", &CustomValidatingStruct{Value: ""}, true},
+		{"invalid custom validating struct pointer - too short", &CustomValidatingStruct{Value: "hi"}, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := ValidateWithCustomValidator(reflect.ValueOf(tt.input))
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ValidateWithCustomValidator() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}