faket

Are your test helpers correct -- test them with faket.

Introduction

Test helper functions play a crucial role in encapsulating common validation patterns and keeping your tests DRY (Don't Repeat Yourself).

These helpers often accept a testing.TB to report failures but it can be tricky to test failure scenarios.

As these helpers grow in complexity and become widely used, verifying their behaviour becomes important-- your tests' correctness depends upon them!

Failure handling by test helpers is particularly critical:

• Do they indicate all errors, or fail on required checks?
• Is the output formatted correctly and does it include all relevant information?

faket addresses these challenges by providing a fake testing.TB so you can validate correctness of your test helpers and ensure the reported messages are accurate and meaningful.

Let's take an example helper used to verify if a string contains expected substrings in order:

func StrContainsInOrder(t testing.TB, got string, contains ...string)

faket can be used to test that the helper behaves as expected:

func TestStrContainsInOrder(t *testing.T) {
  t.Run("correct order", func(t *testing.T) {
    faket.RunTest(func(t testing.TB) {
      StrContainsInOrder(t, "test helper function", "test", "helper")
    }).MustPass(t)
  })

  t.Run("incorrect order", func(t *testing.T) {
    faket.RunTest(func(t testing.TB) {
      StrContainsInOrder(t, "test helper function", "helper", "test")
    }).MustFail(t, `failed to find "test" in remaining string " function"`)
  })
}

Features

• Fully-featured implementation of testing.TB including Skip, Fatal, and Cleanup.
• Thoroughly tested against the real testing.TB implementations to ensure correct behaviour
  • E.g., ensuring skips within cleanups work the same way.
• Panic handling.

There are still some features to implement, see TODO.

Installation

go get -u github.com/prashantv/faket

faket is only supported and tested against the 2 most recent minor versions of Go.

Development Status: Development

This library is still in development, and is not API stable.