Rename function for isolated database connection

Other ways to clean the database in tests will be added soon, so the
tests are being moved to a separate file.

README.md

@@ -76,8 +76,7 @@ total:	(statements)	100.0%
 - Example of test database connection management
   in [testingpg](https://github.com/xorcare/testing-go-code-with-postgres/tree/main/testingpg)
   package.
-- Example of
-  integration [tests](https://github.com/xorcare/testing-go-code-with-postgres/blob/main/user_repository_test.go).
+- [Example of integration testing with isolated database for each testcase](https://github.com/xorcare/testing-go-code-with-postgres/blob/main/user_repository_with_isolated_database_test.go).
 - And example
   of [GitHub Actions](https://github.com/xorcare/testing-go-code-with-postgres/blob/main/.github/workflows/go.yml)
   and [Gitlab CI](https://github.com/xorcare/testing-go-code-with-postgres/blob/main/.gitlab-ci.yml).

testingpg/testingpg.go

@@ -31,7 +31,7 @@ type TestingT interface {
 	Failed() bool
 }
 
-func New(t TestingT) *Postgres {
+func NewWithIsolatedDatabase(t TestingT) *Postgres {
 	return newPostgres(t).cloneFromReference()
 }
 

testingpg/testingpg_test.go

@@ -25,7 +25,7 @@ func TestNewPostgres(t *testing.T) {
 		t.Parallel()
 
 		// Arrange
-		postgres := testingpg.New(t)
+		postgres := testingpg.NewWithIsolatedDatabase(t)
 
 		ctx := context.Background()
 		dbPool, err := pgxpool.New(ctx, postgres.URL())
@@ -45,7 +45,7 @@ func TestNewPostgres(t *testing.T) {
 		t.Parallel()
 
 		// Arrange
-		postgres := testingpg.New(t)
+		postgres := testingpg.NewWithIsolatedDatabase(t)
 		ctx := context.Background()
 
 		// Act
@@ -63,8 +63,8 @@ func TestNewPostgres(t *testing.T) {
 		t.Parallel()
 
 		// Arrange
-		postgres1 := testingpg.New(t)
-		postgres2 := testingpg.New(t)
+		postgres1 := testingpg.NewWithIsolatedDatabase(t)
+		postgres2 := testingpg.NewWithIsolatedDatabase(t)
 
 		ctx := context.Background()
 
@@ -82,8 +82,8 @@ func TestNewPostgres(t *testing.T) {
 		t.Parallel()
 
 		// Arrange
-		postgres1 := testingpg.New(t)
-		postgres2 := testingpg.New(t)
+		postgres1 := testingpg.NewWithIsolatedDatabase(t)
+		postgres2 := testingpg.NewWithIsolatedDatabase(t)
 
 		// Act
 		url1 := postgres1.URL()

user_repository_test.go

@@ -4,93 +4,7 @@
 
 package testing_go_code_with_postgres_test
 
-import (
-	"context"
-	"testing"
-	"time"
-
-	"github.com/google/uuid"
-	"github.com/stretchr/testify/require"
-
-	rootpkg "github.com/xorcare/testing-go-code-with-postgres"
-	"github.com/xorcare/testing-go-code-with-postgres/testingpg"
-)
-
-func TestUserRepository_CreateUser(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test in short mode")
-	}
-
-	t.Parallel()
-
-	newFullyFiledUser := func() rootpkg.User {
-		return rootpkg.User{
-			ID:        uuid.New(),
-			Username:  "gopher",
-			CreatedAt: time.Now().Truncate(time.Microsecond),
-		}
-	}
-
-	t.Run("Successfully created a User", func(t *testing.T) {
-		t.Parallel()
-
-		// Arrange
-		postgres := testingpg.New(t)
-		repo := rootpkg.NewUserRepository(postgres.DB())
-
-		user := newFullyFiledUser()
-
-		// Act
-		err := repo.CreateUser(context.Background(), user)
-
-		// Assert
-		require.NoError(t, err)
-
-		gotUser, err := repo.ReadUser(context.Background(), user.ID)
-		require.NoError(t, err)
-
-		require.Equal(t, user, gotUser)
-	})
-
-	t.Run("Cannot create a user with the same ID", func(t *testing.T) {
-		t.Parallel()
-
-		// Arrange
-		postgres := testingpg.New(t)
-		repo := rootpkg.NewUserRepository(postgres.DB())
-
-		user := newFullyFiledUser()
-
-		err := repo.CreateUser(context.Background(), user)
-		require.NoError(t, err)
-
-		// Act
-		err = repo.CreateUser(context.Background(), user)
-
-		// Assert
-		require.Error(t, err)
-		require.Contains(t, err.Error(), "duplicate key value violates unique constraint")
-	})
-}
-
-func TestUserRepository_ReadUser(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test in short mode")
-	}
-
-	t.Parallel()
-
-	t.Run("Get an error if the user does not exist", func(t *testing.T) {
-		t.Parallel()
-
-		// Arrange
-		postgres := testingpg.New(t)
-		repo := rootpkg.NewUserRepository(postgres.DB())
-
-		// Act
-		_, err := repo.ReadUser(context.Background(), uuid.New())
-
-		// Assert
-		require.Error(t, err)
-	})
-}
+// Since the repository contains examples of different approaches to
+// database cleanup, this file is empty. The specific tests can be found
+// in the following files:
+// - user_repository_with_isolated_database_test.go

user_repository_with_isolated_database_test.go

@@ -0,0 +1,96 @@
+// Copyright (c) 2023 Vasiliy Vasilyuk. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testing_go_code_with_postgres_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+
+	rootpkg "github.com/xorcare/testing-go-code-with-postgres"
+	"github.com/xorcare/testing-go-code-with-postgres/testingpg"
+)
+
+func TestUserRepository_CreateUser(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
+	t.Parallel()
+
+	newFullyFiledUser := func() rootpkg.User {
+		return rootpkg.User{
+			ID:        uuid.New(),
+			Username:  "gopher",
+			CreatedAt: time.Now().Truncate(time.Microsecond),
+		}
+	}
+
+	t.Run("Successfully created a User", func(t *testing.T) {
+		t.Parallel()
+
+		// Arrange
+		postgres := testingpg.NewWithIsolatedDatabase(t)
+		repo := rootpkg.NewUserRepository(postgres.DB())
+
+		user := newFullyFiledUser()
+
+		// Act
+		err := repo.CreateUser(context.Background(), user)
+
+		// Assert
+		require.NoError(t, err)
+
+		gotUser, err := repo.ReadUser(context.Background(), user.ID)
+		require.NoError(t, err)
+
+		require.Equal(t, user, gotUser)
+	})
+
+	t.Run("Cannot create a user with the same ID", func(t *testing.T) {
+		t.Parallel()
+
+		// Arrange
+		postgres := testingpg.NewWithIsolatedDatabase(t)
+		repo := rootpkg.NewUserRepository(postgres.DB())
+
+		user := newFullyFiledUser()
+
+		err := repo.CreateUser(context.Background(), user)
+		require.NoError(t, err)
+
+		// Act
+		err = repo.CreateUser(context.Background(), user)
+
+		// Assert
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "duplicate key value violates unique constraint")
+	})
+}
+
+func TestUserRepository_ReadUser(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
+	t.Parallel()
+
+	t.Run("Get an error if the user does not exist", func(t *testing.T) {
+		t.Parallel()
+
+		// Arrange
+		postgres := testingpg.NewWithIsolatedDatabase(t)
+		repo := rootpkg.NewUserRepository(postgres.DB())
+
+		// Act
+		_, err := repo.ReadUser(context.Background(), uuid.New())
+
+		// Assert
+		require.Error(t, err)
+	})
+}