Add test for error-translator-test.go (#73)

* Add test for error-translator-test.go

Author: Harshit-Khasnis

tests/error_translator_test.go

@@ -145,3 +145,161 @@ func TestSupportedDialectorWithErrForeignKeyViolated(t *testing.T) {
 		t.Fatalf("expected err: %v got err: %v", gorm.ErrForeignKeyViolated, err)
 	}
 }
+
+func TestDialectorWithErrorTranslatorNegativeCases(t *testing.T) {
+	translatedErr := errors.New("translated error")
+	untranslatedErr := errors.New("some random error")
+
+	db, _ := gorm.Open(tests.DummyDialector{TranslatedErr: translatedErr})
+	err := db.AddError(nil)
+	if err != nil {
+		t.Fatalf("expected nil, got %v", err)
+	}
+
+	db, _ = gorm.Open(tests.DummyDialector{TranslatedErr: nil}, &gorm.Config{TranslateError: true})
+	err = db.AddError(untranslatedErr)
+	if err != nil {
+    	t.Fatalf("expected nil when TranslatedErr is nil, got %v", err)
+	}	
+
+	db, _ = gorm.Open(tests.DummyDialector{TranslatedErr: translatedErr}, &gorm.Config{TranslateError: true})
+	err = db.AddError(translatedErr)
+	if !errors.Is(err, translatedErr) {
+		t.Fatalf("expected translatedErr unchanged, got %v", err)
+	}
+}
+
+func TestSupportedDialectorWithErrDuplicatedKeyNegative(t *testing.T) {
+	type City struct {
+		gorm.Model
+		Name string `gorm:"unique"`
+		Code string `gorm:"unique"`
+	}
+
+	db, err := OpenTestConnection(&gorm.Config{TranslateError: false})
+	if err != nil {
+		t.Fatalf("failed to connect database, got error %v", err)
+	}
+
+	dialectors := map[string]bool{"sqlite": true, "postgres": true, "mysql": true, "sqlserver": true}
+	if supported, found := dialectors[db.Dialector.Name()]; !(found && supported) {
+		t.Logf("skipping test for unsupported dialector: %s", db.Dialector.Name())
+		return
+	}
+
+	DB.Migrator().DropTable(&City{})
+	if err = db.AutoMigrate(&City{}); err != nil {
+		t.Fatalf("failed to migrate cities table, got error: %v", err)
+	}
+
+	if err := db.Create(&City{Name: "Kabul", Code: "KB"}).Error; err != nil {
+		t.Fatalf("failed to create record: %v", err)
+	}
+
+	err = db.Create(&City{Name: "Kabul", Code: "KB"}).Error
+	if errors.Is(err, gorm.ErrDuplicatedKey) {
+		t.Fatalf("expected raw db error (no translation), got: %v", err)
+	}
+
+	db, err = OpenTestConnection(&gorm.Config{TranslateError: true})
+	if err != nil {
+		t.Fatalf("failed to connect database, got error %v", err)
+	}
+	DB.Migrator().DropTable(&City{})
+	if err = db.AutoMigrate(&City{}); err != nil {
+		t.Fatalf("failed to migrate cities table, got error: %v", err)
+	}
+
+	if err := db.Create(&City{Name: "Paris", Code: "P1"}).Error; err != nil {
+		t.Fatalf("failed to create record: %v", err)
+	}
+
+	err = db.Create(&City{Name: "London", Code: "P1"}).Error
+	if !errors.Is(err, gorm.ErrDuplicatedKey) {
+		t.Errorf("expected ErrDuplicatedKey on unique Code, got: %v", err)
+	}
+
+	var cities []City
+	if err := db.Find(&cities, "code = ?", "P1").Error; err != nil {
+		t.Fatalf("failed to fetch cities: %v", err)
+	}
+	if len(cities) != 1 {
+		t.Fatalf("expected 1 city with code 'P1', found %d", len(cities))
+	}
+	if cities[0].Name != "Paris" {
+		t.Errorf("expected city name 'Paris', got '%s'", cities[0].Name)
+	}
+
+	if err := db.Create(&City{Name: "NullCodeCity", Code: ""}).Error; err != nil {
+		t.Fatalf("failed to create record with empty Code: %v", err)
+	}
+	if err := db.Create(&City{Name: "NullCodeCity2"}).Error; err != nil {
+		t.Fatalf("failed to create second record with NULL Code: %v", err)
+	}
+}
+
+func TestSupportedDialectorWithErrForeignKeyViolatedNegative(t *testing.T) {
+	type City struct {
+		gorm.Model
+		Name string `gorm:"unique"`
+	}
+
+	type Museum struct {
+		gorm.Model
+		Name   string `gorm:"unique"`
+		CityID uint
+		City   City `gorm:"Constraint:OnUpdate:CASCADE,OnDelete:CASCADE;FOREIGNKEY:CityID;References:ID"`
+	}
+
+	db, err := OpenTestConnection(&gorm.Config{TranslateError: false})
+	if err != nil {
+		t.Fatalf("failed to connect database, got error %v", err)
+	}
+
+	dialectors := map[string]bool{"sqlite": true, "postgres": true, "mysql": true, "sqlserver": true}
+	if supported, found := dialectors[db.Dialector.Name()]; !(found && supported) {
+		t.Logf("skipping test for unsupported dialector: %s", db.Dialector.Name())
+		return
+	}
+
+	DB.Migrator().DropTable(&Museum{}, &City{})
+	if err = db.AutoMigrate(&City{}, &Museum{}); err != nil {
+		t.Fatalf("failed to migrate tables, got error: %v", err)
+	}
+
+	city := City{Name: "Berlin"}
+	if err := db.Create(&city).Error; err != nil {
+		t.Fatalf("failed to create city: %v", err)
+	}
+
+	err = db.Create(&Museum{Name: "Invalid FK Museum", CityID: 99999}).Error
+	if errors.Is(err, gorm.ErrForeignKeyViolated) {
+		t.Fatalf("expected raw DB error without translation, got: %v", err)
+	}
+
+	db, err = OpenTestConnection(&gorm.Config{TranslateError: true})
+	if err != nil {
+		t.Fatalf("failed to connect database, got error %v", err)
+	}
+	DB.Migrator().DropTable(&Museum{}, &City{})
+	if err = db.AutoMigrate(&City{}, &Museum{}); err != nil {
+		t.Fatalf("failed to migrate tables, got error: %v", err)
+	}
+
+	city2 := City{Name: "Vienna"}
+	if err := db.Create(&city2).Error; err != nil {
+		t.Fatalf("failed to create city: %v", err)
+	}
+	museum := Museum{Name: "Vienna Museum", CityID: city2.ID}
+	if err := db.Create(&museum).Error; err != nil {
+		t.Fatalf("failed to create museum: %v", err)
+	}
+
+	if err := db.Delete(&city2).Error; err != nil {
+		t.Fatalf("expected cascade delete success, got error: %v", err)
+	}
+
+	if err := db.Create(&Museum{Name: "Orphan Museum"}).Error; err != nil {
+		t.Fatalf("expected orphan museum insert to succeed, got: %v", err)
+	}
+}