Testing

Testing Backed in From the Get-Go

• ✅ Unit - all packages come with unit testing abilities
• ⏳ Integration - helpers to make your integration tests easier
• 💤 E2E
• 💤 UI
• Manual - always left to you

Convention

All packages provide helpers to make testing easy

• Constructors for regular logic start with New
• Constructors for tests start with Test. Returning objects that assist your code in being tested well.

Semantic Assertions

Many packages come with specialised test helpers and assertions. These can be used in combination with the assertions from stretchr/testify and the Go standard library.

Repository	Queue	Logger	Renderer	Database
Empty ✅	Empty ✅	Empty ✅
NotEmpty ✅	NotEmpty ✅	NotEmpty ✅
Total ✅	Total ✅	Total ✅
Contains	Contains ✅	Contains ✅
NotContains	NotContains ✅	NotContains ✅
HasEntity (?)	HasJob (?)	HasLine (?)
HasNotEntity (?)	HasNotJob (?)	NasNotLine (?)
	Jobs ✅	Lines ✅
	GetFirst ✅	String ✅
	Get ✅
	GetFirstOf✅
	GetOf ✅
	Reset (?)

Integration Testing

Sometimes you just don't want to test against an in memory implementation and need to see if your application behaves correctly against the real database.

This pattern spins up a postgres database inside a docker container and removes the container after the test has finished automatically. The NewTestDatabase method will ensure you can safely run all tests in parallel by:

• Creating a new randomly named database for each test case
• Performing schema migration
• Seeding the database with test data

The testdata is seeded with the project testfixtures and if an file testdata/fixtures/_common.yaml exists it is automatically loaded. For additional data per test case take a look at multiple tables in one file

//go:build integration

package yourpackage_test

var pgHandler *tests.PostgresDocker

func TestMain(m *testing.M) {
	pgHandler = tests.GetPostgresDockerForIntegrationTestingInstance()

	//
	// Run tests
	code := m.Run()

	pgHandler.Cleanup()
	os.Exit(code)
}

func TestSomething(t *testing.T) {
	t.Parallel()

	pg := pgHandler.NewTestDatabase()

	// use pg to initialise your test dependencies like a postgres repository 
}

func TestSomethingOther(t *testing.T) {
	t.Parallel()

	// load multiple additional test fixture files to seed the database
	pg := pgHandler.NewTestDatabase([]string{
		"testdata/fixtures/something-other-user.yaml",
		"testdata/fixtures/something-other-posts.yaml",
    })
	
	_ = pg.PGx() // direct access to the pgx connection pool 
}

The PrepareDatabase method is similar to NewTestDatabase but does not create a new database but cleans the existing database!

• All data is truncated
• It cannot be used in parallel

If you depend on other services for your testing use the tests.StartDockerContainer helper to start any service inside a docker container. Check out the tests.GetPostgresDockerForIntegrationTestingInstance to see it in action for the testing against a postgres database as shown above.

Docker Images for Integration Testing

Arrower ships all images you would need to operate and test a setup. See Alternatives on how to use the postgres image with a preinstalled pg_cron extension already