What tools and approaches do you use for integration testing in your projects?

For integration tests in Go projects, I usually apply the following approaches and tools:

• Test frameworks: the standard testing package along with libraries like testify for convenient assertions.

• Environment isolation: using Docker containers to set up dependencies (databases, cache, external services) in the test environment.

• Test data: preparing fixtures or using migrations to create the necessary database state before tests.

• Mock and stub: for external services, if integration with them is not mandatory or too costly.

• CI/CD integration: running integration tests in pipelines for automatic verification.

Example of a simple integration test using testing and connecting to a test database:

func TestCreateUserIntegration(t *testing.T) {
    db, err := sql.Open("postgres", "connection_string_to_test_db")
    if err != nil {
        t.Fatal(err)
    }
    defer db.Close()

    userRepo := NewUserRepository(db)
    user := User{Name: "Test User", Email: "test@example.com"}

    err = userRepo.Create(user)
    if err != nil {
        t.Errorf("failed to create user: %v", err)
    }

    // Check that the user was actually created
    savedUser, err := userRepo.FindByEmail(user.Email)
    if err != nil || savedUser == nil {
        t.Errorf("user not found after creation")
    }
}

Thus, integration tests verify the interaction of multiple system components together.