Testify require and assert

External

• https://pkg.go.dev/github.com/stretchr/testify#readme-assert-package

Internal

• Testify

Equality and Non-Equality

In case the result is failure, Equal() and NotEqual() delegate to Fail().

package somepkg

import (
	"testing"

	testifyassert "github.com/stretchr/testify/assert"
)

func TestSomething(t *testing.T) {
	assert := testifyassert.New(t)
	assert.Equal(123, 123, "this message is displayed when the test fails %s", "because of inequality")
	assert.NotEqual(123, 321, "this message is displayed when the test fails %s", "because of equality")
}

Nil and Non-Nil

In case the result is failure, Nil() and NotNil() delegate to Fail().

package somepkg

import (
	"testing"

	testifyassert "github.com/stretchr/testify/assert"
)

func TestSomething(t *testing.T) {
	assert := testifyassert.New(t)
	someObj := &struct{}{}
	assert.NotNil(someObj, "someObj should not have been nil but it is %v", someObj)
	someObj = nil
	assert.Nil(someObj, "someObj should have been nil but it is %v", someObj)
}

Failing the Test

Failing a Test from a Goroutine

package yours

import (
  "testing"
  tassert "github.com/stretchr/testify/assert"
)

func TestSomething(t *testing.T) {

  assert := tassert.New(t)

  // assert equality
  assert.Equal(123, 123, "they should be equal")

  // assert inequality
  assert.NotEqual(123, 456, "they should not be equal")

  // assert for nil (good for errors)
  assert.Nil(object)

  // assert for not nil (good when you expect something)
  if assert.NotNil(object) {

    // now we know that object isn't nil, we are safe to make
    // further assertions without causing any errors
    assert.Equal("Something", object.Value)
  }
}

To check that an error has the expected message:

err := ...
assert.NotNil(err)
assert.Equal(err.Error(), "expected message")