testify
v1.9.0
Note
Testify is being maintained at v1, no breaking changes will be accepted in this repo.
See discussion about v2.
Go code (golang) set of packages that provide many tools for testifying that your code will behave as you intend.
Features include:
Easy assertions
Mocking
Testing suite interfaces and functions
Get started:
Install testify with one line of code, or update it with another
For an introduction to writing test code in Go, see https://go.dev/doc/code#Testing
Check out the API Documentation https://pkg.go.dev/github.com/stretchr/testify
Use testifylint (via golanci-lint) to avoid common mistakes
A little about Test-Driven Development (TDD)
assert packageThe assert package provides some helpful methods that allow you to write better test code in Go.
Prints friendly, easy to read failure descriptions
Allows for very readable code
Optionally annotate each assertion with a message
See it in action:
package yoursimport ( "testing"
"github.com/stretchr/testify/assert")func TestSomething(t *testing.T) { // assert equality
assert.Equal(t, 123, 123, "they should be equal") // assert inequality
assert.NotEqual(t, 123, 456, "they should not be equal") // assert for nil (good for errors)
assert.Nil(t, object) // assert for not nil (good when you expect something)
if assert.NotNil(t, object) {// now we know that object isn't nil, we are safe to make// further assertions without causing any errorsassert.Equal(t, "Something", object.Value)
}
}Every assert func takes the testing.T object as the first argument. This is how it writes the errors out through the normal go test capabilities.
Every assert func returns a bool indicating whether the assertion was successful or not, this is useful for if you want to go on making further assertions under certain conditions.
if you assert many times, use the below:
package yoursimport ( "testing"
"github.com/stretchr/testify/assert")func TestSomething(t *testing.T) { assert := assert.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 errorsassert.Equal("Something", object.Value)
}
}require packageThe require package provides same global functions as the assert package, but instead of returning a boolean result they terminate current test.
These functions must be called from the goroutine running the test or benchmark function, not from other goroutines created during the test.
Otherwise race conditions may occur.
See t.FailNow for details.
mock packageThe mock package provides a mechanism for easily writing mock objects that can be used in place of real objects when writing test code.
An example test function that tests a piece of code that relies on an external object testObj, can set up expectations (testify) and assert that they indeed happened:
package yoursimport ( "testing"
"github.com/stretchr/testify/mock")/* Test objects*/// MyMockedObject is a mocked object that implements an interface// that describes an object that the code I am testing relies on.type MyMockedObject struct{
mock.Mock}// DoSomething is a method on MyMockedObject that implements some interface// and just records the activity, and returns what the Mock object tells it to.//// In the real object, this method would do something useful, but since this// is a mocked object - we're just going to stub it out.//// NOTE: This method is not being tested here, code that uses this object is.func (m *MyMockedObject) DoSomething(number int) (bool, error) { args := m.Called(number) return args.Bool(0), args.Error(1)
}/* Actual test functions*/// TestSomething is an example of how to use our test object to// make assertions about some target code we are testing.func TestSomething(t *testing.T) { // create an instance of our test object
testObj := new(MyMockedObject) // set up expectations
testObj.On("DoSomething", 123).Return(true, nil) // call the code we are testing
targetFuncThatDoesSomethingWithObj(testObj) // assert that the expectations were met
testObj.AssertExpectations(t)
}// TestSomethingWithPlaceholder is a second example of how to use our test object to// make assertions about some target code we are testing.// This time using a placeholder. Placeholders might be used when the// data being passed in is normally dynamically generated and cannot be// predicted beforehand (eg. containing hashes that are time sensitive)func TestSomethingWithPlaceholder(t *testing.T) { // create an instance of our test object
testObj := new(MyMockedObject) // set up expectations with a placeholder in the argument list
testObj.On("DoSomething", mock.Anything).Return(true, nil) // call the code we are testing
targetFuncThatDoesSomethingWithObj(testObj) // assert that the expectations were met
testObj.AssertExpectations(t)
}// TestSomethingElse2 is a third example that shows how you can use// the Unset method to cleanup handlers and then add new ones.func TestSomethingElse2(t *testing.T) { // create an instance of our test object
testObj := new(MyMockedObject) // set up expectations with a placeholder in the argument list
mockCall := testObj.On("DoSomething", mock.Anything).Return(true, nil) // call the code we are testing
targetFuncThatDoesSomethingWithObj(testObj) // assert that the expectations were met
testObj.AssertExpectations(t) // remove the handler now so we can add another one that takes precedence
mockCall.Unset() // return false now instead of true
testObj.On("DoSomething", mock.Anything).Return(false, nil) testObj.AssertExpectations(t)
}For more information on how to write mock code, check out the API documentation for the mock package.
You can use the mockery tool to autogenerate the mock code against an interface as well, making using mocks much quicker.
suite packageWarning
The suite package does not support parallel tests. See #934.
The suite package provides functionality that you might be used to from more common object-oriented languages. With it, you can build a testing suite as a struct, build setup/teardown methods and testing methods on your struct, and run them with 'go test' as per normal.
An example suite is shown below:
// Basic importsimport ("testing""github.com/stretchr/testify/assert""github.com/stretchr/testify/suite")// Define the suite, and absorb the built-in basic suite// functionality from testify - including a T() method which// returns the current testing contexttype ExampleTestSuite struct {
suite.SuiteVariableThatShouldStartAtFive int}// Make sure that VariableThatShouldStartAtFive is set to five// before each testfunc (suite *ExampleTestSuite) SetupTest() {suite.VariableThatShouldStartAtFive = 5}// All methods that begin with "Test" are run as tests within a// suite.func (suite *ExampleTestSuite) TestExample() {assert.Equal(suite.T(), 5, suite.VariableThatShouldStartAtFive)
}// In order for 'go test' to run this suite, we need to create// a normal test function and pass our suite to suite.Runfunc TestExampleTestSuite(t *testing.T) {suite.Run(t, new(ExampleTestSuite))
}For a more complete example, using all of the functionality provided by the suite package, look at our example testing suite
For more information on writing suites, check out the API documentation for the suite package.
Suite object has assertion methods:
// Basic importsimport ("testing""github.com/stretchr/testify/suite")// Define the suite, and absorb the built-in basic suite// functionality from testify - including assertion methods.type ExampleTestSuite struct {
suite.SuiteVariableThatShouldStartAtFive int}// Make sure that VariableThatShouldStartAtFive is set to five// before each testfunc (suite *ExampleTestSuite) SetupTest() {suite.VariableThatShouldStartAtFive = 5}// All methods that begin with "Test" are run as tests within a// suite.func (suite *ExampleTestSuite) TestExample() {suite.Equal(suite.VariableThatShouldStartAtFive, 5)
}// In order for 'go test' to run this suite, we need to create// a normal test function and pass our suite to suite.Runfunc TestExampleTestSuite(t *testing.T) {suite.Run(t, new(ExampleTestSuite))
}To install Testify, use go get:
go get github.com/stretchr/testify
This will then make the following packages available to you:
github.com/stretchr/testify/assert github.com/stretchr/testify/require github.com/stretchr/testify/mock github.com/stretchr/testify/suite github.com/stretchr/testify/http (deprecated)
Import the testify/assert package into your code using this template:
package yoursimport ( "testing"
"github.com/stretchr/testify/assert")func TestSomething(t *testing.T) { assert.True(t, true, "True is true!")
}To update Testify to the latest version, use go get -u github.com/stretchr/testify.
We currently support the most recent major Go versions from 1.19 onward.
Please feel free to submit issues, fork the repository and send pull requests!
When submitting an issue, we ask that you please include a complete test function that demonstrates the issue. Extra credit for those using Testify to write the test code that demonstrates it.
Code generation is used. Look for Code generated with at the top of some files. Run go generate ./... to update generated files.
We also chat on the Gophers Slack group in the #testify and #testify-dev channels.
This project is licensed under the terms of the MIT license.
