Refactor repository tests to be more DRY and maintainable.

Introduced a new testing strategy for the data access layer to avoid redundant testing of generic repository methods.

- Created a comprehensive test suite for the generic `BaseRepository` using a dedicated `TestEntity`. This suite covers all common CRUD operations, including transactions and error handling, in a single location.
- Added a new, focused test suite for `CategoryRepository` that only tests its repository-specific methods, relying on the base repository tests for generic functionality.
- Refactored the existing `AuthorRepository` test suite to remove redundant CRUD tests, aligning it with the new, cleaner pattern.
- Updated the test utilities to support the new testing strategy.

This change significantly improves the maintainability and efficiency of the test suite and provides a clear, future-proof pattern for testing all repositories.

internal/data/sql/author_repository_test.go

@@ -17,93 +17,30 @@ func (s *AuthorRepositoryTestSuite) SetupSuite() {
 	s.IntegrationTestSuite.SetupSuite(testutil.DefaultTestConfig())
 }
 
-func (s *AuthorRepositoryTestSuite) TestCreateAuthor() {
-	s.Run("should create a new author", func() {
-		// Arrange
-		author := &domain.Author{
-			Name: "New Test Author",
-			TranslatableModel: domain.TranslatableModel{
-				Language: "en",
-			},
-		}
-
-		// Act
-		err := s.AuthorRepo.Create(context.Background(), author)
-
-		// Assert
-		s.Require().NoError(err)
-		s.NotZero(author.ID)
-
-		// Verify that the author was actually created in the database
-		var foundAuthor domain.Author
-		err = s.DB.First(&foundAuthor, author.ID).Error
-		s.Require().NoError(err)
-		s.Equal("New Test Author", foundAuthor.Name)
-		s.Equal("en", foundAuthor.Language)
-	})
+func (s *AuthorRepositoryTestSuite) SetupTest() {
+	s.DB.Exec("DELETE FROM work_authors")
+	s.DB.Exec("DELETE FROM authors")
+	s.DB.Exec("DELETE FROM works")
 }
 
-func (s *AuthorRepositoryTestSuite) TestGetAuthorByID() {
-	s.Run("should return an author by ID", func() {
-		// Arrange
-		author := &domain.Author{Name: "Test Author"}
-		s.Require().NoError(s.AuthorRepo.Create(context.Background(), author))
-
-		// Act
-		foundAuthor, err := s.AuthorRepo.GetByID(context.Background(), author.ID)
-
-		// Assert
-		s.Require().NoError(err)
-		s.Require().NotNil(foundAuthor)
-		s.Equal(author.ID, foundAuthor.ID)
-		s.Equal("Test Author", foundAuthor.Name)
-	})
-}
-
-func (s *AuthorRepositoryTestSuite) TestUpdateAuthor() {
-	s.Run("should update an existing author", func() {
-		// Arrange
-		author := &domain.Author{Name: "Original Name"}
-		s.Require().NoError(s.AuthorRepo.Create(context.Background(), author))
-		author.Name = "Updated Name"
-
-		// Act
-		err := s.AuthorRepo.Update(context.Background(), author)
-
-		// Assert
-		s.Require().NoError(err)
-		var foundAuthor domain.Author
-		err = s.DB.First(&foundAuthor, author.ID).Error
-		s.Require().NoError(err)
-		s.Equal("Updated Name", foundAuthor.Name)
-	})
-}
-
-func (s *AuthorRepositoryTestSuite) TestDeleteAuthor() {
-	s.Run("should delete an existing author", func() {
-		// Arrange
-		author := &domain.Author{Name: "To Be Deleted"}
-		s.Require().NoError(s.AuthorRepo.Create(context.Background(), author))
-
-		// Act
-		err := s.AuthorRepo.Delete(context.Background(), author.ID)
-
-		// Assert
-		s.Require().NoError(err)
-		var foundAuthor domain.Author
-		err = s.DB.First(&foundAuthor, author.ID).Error
-		s.Require().Error(err)
-	})
+func (s *AuthorRepositoryTestSuite) createAuthor(name string) *domain.Author {
+	author := &domain.Author{
+		Name: name,
+		TranslatableModel: domain.TranslatableModel{
+			Language: "en",
+		},
+	}
+	err := s.AuthorRepo.Create(context.Background(), author)
+	s.Require().NoError(err)
+	return author
 }
 
 func (s *AuthorRepositoryTestSuite) TestListByWorkID() {
 	s.Run("should return all authors for a given work", func() {
 		// Arrange
 		work := s.CreateTestWork("Test Work", "en", "Test content")
-		author1 := &domain.Author{Name: "Author 1"}
-		author2 := &domain.Author{Name: "Author 2"}
-		s.Require().NoError(s.AuthorRepo.Create(context.Background(), author1))
-		s.Require().NoError(s.AuthorRepo.Create(context.Background(), author2))
+		author1 := s.createAuthor("Author 1")
+		author2 := s.createAuthor("Author 2")
 		s.Require().NoError(s.DB.Model(&work).Association("Authors").Append([]*domain.Author{author1, author2}))
 
 		// Act
@@ -112,6 +49,7 @@ func (s *AuthorRepositoryTestSuite) TestListByWorkID() {
 		// Assert
 		s.Require().NoError(err)
 		s.Len(authors, 2)
+		s.ElementsMatch([]string{"Author 1", "Author 2"}, []string{authors[0].Name, authors[1].Name})
 	})
 }
 

internal/data/sql/base_repository_test.go

@@ -0,0 +1,259 @@
+package sql_test
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"tercul/internal/data/sql"
+	"tercul/internal/domain"
+	"tercul/internal/testutil"
+
+	"github.com/stretchr/testify/suite"
+	"gorm.io/gorm"
+)
+
+// BaseRepositoryTestSuite tests the generic BaseRepository implementation.
+type BaseRepositoryTestSuite struct {
+	testutil.IntegrationTestSuite
+	repo domain.BaseRepository[testutil.TestEntity]
+}
+
+// SetupSuite initializes the test suite, database, and repository.
+func (s *BaseRepositoryTestSuite) SetupSuite() {
+	s.IntegrationTestSuite.SetupSuite(testutil.DefaultTestConfig())
+	s.repo = sql.NewBaseRepositoryImpl[testutil.TestEntity](s.DB)
+}
+
+// SetupTest cleans the database before each test.
+func (s *BaseRepositoryTestSuite) SetupTest() {
+	s.DB.Exec("DELETE FROM test_entities")
+}
+
+// TearDownSuite drops the test table after the suite finishes.
+func (s *BaseRepositoryTestSuite) TearDownSuite() {
+	s.DB.Migrator().DropTable(&testutil.TestEntity{})
+}
+
+// TestBaseRepository runs the entire test suite.
+func TestBaseRepository(t *testing.T) {
+	suite.Run(t, new(BaseRepositoryTestSuite))
+}
+
+// createTestEntity is a helper to create a test entity.
+func (s *BaseRepositoryTestSuite) createTestEntity(name string) *testutil.TestEntity {
+	entity := &testutil.TestEntity{Name: name}
+	err := s.repo.Create(context.Background(), entity)
+	s.Require().NoError(err)
+	s.Require().NotZero(entity.ID)
+	return entity
+}
+
+func (s *BaseRepositoryTestSuite) TestCreate() {
+	s.Run("should create a new entity", func() {
+		// Arrange
+		ctx := context.Background()
+		entity := &testutil.TestEntity{Name: "Test Create"}
+
+		// Act
+		err := s.repo.Create(ctx, entity)
+
+		// Assert
+		s.Require().NoError(err)
+		s.NotZero(entity.ID)
+
+		// Verify in DB
+		var foundEntity testutil.TestEntity
+		err = s.DB.First(&foundEntity, entity.ID).Error
+		s.Require().NoError(err)
+		s.Equal("Test Create", foundEntity.Name)
+	})
+
+	s.Run("should return error for nil entity", func() {
+		err := s.repo.Create(context.Background(), nil)
+		s.ErrorIs(err, sql.ErrInvalidInput)
+	})
+
+	s.Run("should return error for nil context", func() {
+		err := s.repo.Create(nil, &testutil.TestEntity{Name: "Test Context"})
+		s.ErrorIs(err, sql.ErrContextRequired)
+	})
+}
+
+func (s *BaseRepositoryTestSuite) TestGetByID() {
+	s.Run("should return an entity by ID", func() {
+		// Arrange
+		created := s.createTestEntity("Test GetByID")
+
+		// Act
+		found, err := s.repo.GetByID(context.Background(), created.ID)
+
+		// Assert
+		s.Require().NoError(err)
+		s.Require().NotNil(found)
+		s.Equal(created.ID, found.ID)
+		s.Equal(created.Name, found.Name)
+	})
+
+	s.Run("should return ErrEntityNotFound for non-existent ID", func() {
+		_, err := s.repo.GetByID(context.Background(), 99999)
+		s.ErrorIs(err, sql.ErrEntityNotFound)
+	})
+
+	s.Run("should return ErrInvalidID for zero ID", func() {
+		_, err := s.repo.GetByID(context.Background(), 0)
+		s.ErrorIs(err, sql.ErrInvalidID)
+	})
+}
+
+func (s *BaseRepositoryTestSuite) TestUpdate() {
+	s.Run("should update an existing entity", func() {
+		// Arrange
+		created := s.createTestEntity("Original Name")
+		created.Name = "Updated Name"
+
+		// Act
+		err := s.repo.Update(context.Background(), created)
+
+		// Assert
+		s.Require().NoError(err)
+		found, getErr := s.repo.GetByID(context.Background(), created.ID)
+		s.Require().NoError(getErr)
+		s.Equal("Updated Name", found.Name)
+	})
+}
+
+func (s *BaseRepositoryTestSuite) TestDelete() {
+	s.Run("should delete an existing entity", func() {
+		// Arrange
+		created := s.createTestEntity("To Be Deleted")
+
+		// Act
+		err := s.repo.Delete(context.Background(), created.ID)
+
+		// Assert
+		s.Require().NoError(err)
+		_, getErr := s.repo.GetByID(context.Background(), created.ID)
+		s.ErrorIs(getErr, sql.ErrEntityNotFound)
+	})
+
+	s.Run("should return ErrEntityNotFound when deleting non-existent entity", func() {
+		err := s.repo.Delete(context.Background(), 99999)
+		s.ErrorIs(err, sql.ErrEntityNotFound)
+	})
+}
+
+func (s *BaseRepositoryTestSuite) TestList() {
+	// Arrange
+	s.createTestEntity("Entity 1")
+	s.createTestEntity("Entity 2")
+	s.createTestEntity("Entity 3")
+
+	s.Run("should return a paginated list of entities", func() {
+		// Act
+		result, err := s.repo.List(context.Background(), 1, 2)
+
+		// Assert
+		s.Require().NoError(err)
+		s.Equal(int64(3), result.TotalCount)
+		s.Equal(2, result.TotalPages)
+		s.Equal(1, result.Page)
+		s.Equal(2, result.PageSize)
+		s.True(result.HasNext)
+		s.False(result.HasPrev)
+		s.Len(result.Items, 2)
+	})
+}
+
+func (s *BaseRepositoryTestSuite) TestListWithOptions() {
+	// Arrange
+	s.createTestEntity("Apple")
+	s.createTestEntity("Banana")
+	s.createTestEntity("Avocado")
+
+	s.Run("should filter with Where clause", func() {
+		// Act
+		options := &domain.QueryOptions{
+			Where: map[string]interface{}{"name LIKE ?": "A%"},
+		}
+		results, err := s.repo.ListWithOptions(context.Background(), options)
+
+		// Assert
+		s.Require().NoError(err)
+		s.Len(results, 2)
+	})
+
+	s.Run("should order results", func() {
+		// Act
+		options := &domain.QueryOptions{OrderBy: "name desc"}
+		results, err := s.repo.ListWithOptions(context.Background(), options)
+
+		// Assert
+		s.Require().NoError(err)
+		s.Len(results, 3)
+		s.Equal("Banana", results[0].Name)
+		s.Equal("Avocado", results[1].Name)
+		s.Equal("Apple", results[2].Name)
+	})
+}
+
+func (s *BaseRepositoryTestSuite) TestCount() {
+	// Arrange
+	s.createTestEntity("Entity 1")
+	s.createTestEntity("Entity 2")
+
+	s.Run("should return the total count of entities", func() {
+		// Act
+		count, err := s.repo.Count(context.Background())
+
+		// Assert
+		s.Require().NoError(err)
+		s.Equal(int64(2), count)
+	})
+}
+
+func (s *BaseRepositoryTestSuite) TestWithTx() {
+	s.Run("should commit transaction on success", func() {
+		// Arrange
+		var createdID uint
+
+		// Act
+		err := s.repo.WithTx(context.Background(), func(tx *gorm.DB) error {
+			entity := &testutil.TestEntity{Name: "TX Commit"}
+			repoInTx := sql.NewBaseRepositoryImpl[testutil.TestEntity](tx)
+			if err := repoInTx.Create(context.Background(), entity); err != nil {
+				return err
+			}
+			createdID = entity.ID
+			return nil
+		})
+
+		// Assert
+		s.Require().NoError(err)
+		_, getErr := s.repo.GetByID(context.Background(), createdID)
+		s.NoError(getErr, "Entity should exist after commit")
+	})
+
+	s.Run("should rollback transaction on error", func() {
+		// Arrange
+		var createdID uint
+		simulatedErr := errors.New("simulated error")
+
+		// Act
+		err := s.repo.WithTx(context.Background(), func(tx *gorm.DB) error {
+			entity := &testutil.TestEntity{Name: "TX Rollback"}
+			repoInTx := sql.NewBaseRepositoryImpl[testutil.TestEntity](tx)
+			if err := repoInTx.Create(context.Background(), entity); err != nil {
+				return err
+			}
+			createdID = entity.ID
+			return simulatedErr // Force a rollback
+		})
+
+		// Assert
+		s.Require().Error(err)
+		s.ErrorIs(err, simulatedErr)
+
+		_, getErr := s.repo.GetByID(context.Background(), createdID)
+		s.ErrorIs(getErr, sql.ErrEntityNotFound, "Entity should not exist after rollback")
+	})
+}

internal/data/sql/category_repository_test.go

@@ -0,0 +1,111 @@
+package sql_test
+
+import (
+	"context"
+	"testing"
+	"tercul/internal/domain"
+	"tercul/internal/testutil"
+
+	"github.com/stretchr/testify/suite"
+)
+
+type CategoryRepositoryTestSuite struct {
+	testutil.IntegrationTestSuite
+}
+
+func (s *CategoryRepositoryTestSuite) SetupSuite() {
+	s.IntegrationTestSuite.SetupSuite(testutil.DefaultTestConfig())
+}
+
+func (s *CategoryRepositoryTestSuite) SetupTest() {
+	s.DB.Exec("DELETE FROM work_categories")
+	s.DB.Exec("DELETE FROM categories")
+	s.DB.Exec("DELETE FROM works")
+}
+
+func TestCategoryRepository(t *testing.T) {
+	suite.Run(t, new(CategoryRepositoryTestSuite))
+}
+
+func (s *CategoryRepositoryTestSuite) createCategory(name string, parentID *uint) *domain.Category {
+	category := &domain.Category{Name: name, ParentID: parentID}
+	err := s.CategoryRepo.Create(context.Background(), category)
+	s.Require().NoError(err)
+	s.Require().NotZero(category.ID)
+	return category
+}
+
+func (s *CategoryRepositoryTestSuite) TestFindByName() {
+	s.Run("should find a category by its name", func() {
+		// Arrange
+		s.createCategory("Fiction", nil)
+
+		// Act
+		found, err := s.CategoryRepo.FindByName(context.Background(), "Fiction")
+
+		// Assert
+		s.Require().NoError(err)
+		s.Require().NotNil(found)
+		s.Equal("Fiction", found.Name)
+	})
+
+	s.Run("should return error if not found", func() {
+		_, err := s.CategoryRepo.FindByName(context.Background(), "NonExistent")
+		s.Require().Error(err)
+	})
+}
+
+func (s *CategoryRepositoryTestSuite) TestListByWorkID() {
+	s.Run("should return all categories for a given work", func() {
+		// Arrange
+		work := s.CreateTestWork("Test Work", "en", "Test content")
+		cat1 := s.createCategory("Science Fiction", nil)
+		cat2 := s.createCategory("Cyberpunk", &cat1.ID)
+
+		err := s.DB.Model(&work).Association("Categories").Append([]*domain.Category{cat1, cat2})
+		s.Require().NoError(err)
+
+		// Act
+		categories, err := s.CategoryRepo.ListByWorkID(context.Background(), work.ID)
+
+		// Assert
+		s.Require().NoError(err)
+		s.Len(categories, 2)
+		s.ElementsMatch([]string{"Science Fiction", "Cyberpunk"}, []string{categories[0].Name, categories[1].Name})
+	})
+}
+
+func (s *CategoryRepositoryTestSuite) TestListByParentID() {
+	s.Run("should return top-level categories when parent ID is nil", func() {
+		// Arrange
+		s.createCategory("Root 1", nil)
+		s.createCategory("Root 2", nil)
+		child := s.createCategory("Child 1", &[]uint{1}[0]) // Create a child to ensure it's not returned
+
+		// Act
+		categories, err := s.CategoryRepo.ListByParentID(context.Background(), nil)
+
+		// Assert
+		s.Require().NoError(err)
+		s.Len(categories, 2)
+		s.NotContains(categories, child)
+	})
+
+	s.Run("should return child categories for a given parent ID", func() {
+		// Arrange
+		parent := s.createCategory("Parent", nil)
+		s.createCategory("Sub-Child 1", &parent.ID)
+		s.createCategory("Sub-Child 2", &parent.ID)
+		s.createCategory("Another Parent", nil)
+
+		// Act
+		categories, err := s.CategoryRepo.ListByParentID(context.Background(), &parent.ID)
+
+		// Assert
+		s.Require().NoError(err)
+		s.Len(categories, 2)
+		for _, cat := range categories {
+			s.Equal(parent.ID, *cat.ParentID)
+		}
+	})
+}

internal/testutil/integration_test_utils.go

@@ -171,6 +171,7 @@ func (s *IntegrationTestSuite) setupInMemoryDB(config *TestConfig) {
 		&domain.TextMetadata{},
 		&domain.PoeticAnalysis{},
 		&domain.TranslationField{},
+		&TestEntity{}, // Add TestEntity for generic repository tests
 	); err != nil {
 		s.T().Fatalf("Failed to run migrations: %v", err)
 	}

internal/testutil/test_entity.go

@@ -0,0 +1,10 @@
+package testutil
+
+import "gorm.io/gorm"
+
+// TestEntity is a simple struct used for testing the generic BaseRepository.
+// It is not used in the main application.
+type TestEntity struct {
+	gorm.Model
+	Name string
+}