golden - Golden test utility for Go

golden is a golden file test utility for Go projects. It's typically used for testing responses with larger data bodies.

The concept is straight forward. Valid response data is stored in a "golden file". The actual response data will be byte compared with the golden file and the test will fail if there is a difference. Updating the golden file can be done by running go test -update ./....

See the GoDoc for API reference and configuration options. This project is forked from github.com/sebdah/goldie. Original project (== goldie) is not support windows. Also, there is deprecated function and not enough unit tests. So, I forked it over with the goal is improved reliability and stability.

Support OS

• Windows
• Mac
• Linux

Example usage

Basic assertions

The below example fetches data from a REST API. The last line in the test is the actual usage of golden. It takes the HTTP response body and asserts that it's what is present in the golden test file.

func TestExample(t *testing.T) {
    recorder := httptest.NewRecorder()

    req, err := http.NewRequest("GET", "/example", nil)
    assert.Nil(t, err)

    handler := http.HandlerFunc(ExampleHandler)
    handler.ServeHTTP()

    g := golden.New(t)
    // Compare testdata/example.golden and recorder.Body.Bytes()
    g.Assert(t, "example", recorder.Body.Bytes())
}

Assertions using templates

If some values in the golden file can change depending on the test, you can use golang template in the golden file and pass the data to AssertWithTemplate.

example.golden

This is a {{ .Type }} file.

Test

func TestTemplateExample(t *testing.T) {
    recorder := httptest.NewRecorder()

    req, err := http.NewRequest("POST", "/example/Golden", nil)
    assert.Nil(t, err)

    handler := http.HandlerFunc(ExampleHandler)
    handler.ServeHTTP()

    data := struct {
        Type	string
    }{
        Type:	"Golden",
    }

    g := golden.New(t)
    g.AssertWithTemplate(t, "example", data, recorder.Body.Bytes())
}

Then run your test with the -update flag the first time to store the result.

go test -update ./...

For any consecutive runs where you actually want to compare the data, simply drop the -update flag.

go test ./...

Validating JSON and XML output

If you are asserting JSON and XML data, you can use the handy AssertJson and AssertXml functions that will nicely indent the golden validation files for better readability.

Flags

Clean output directory

Using -update along with -clean flag will clear the fixture directory before updating golden files.

go test -update -clean ./...

Options

golden supports a number of configuration options that will alter the behavior of the library. These options should be passed into the golden.New() method.

func TestNewExample(t *testing.T) {
    g := golden.New(
        t,
        golden.WithFixtureDir("test-fixtures"),
        golden.WithNameSuffix(".golden.json"),
        golden.WithDiffEngine(golden.ColoredDiff),
        golden.WithTestNameForDir(true),
    )

    g.Assert(t, "example", []byte("my example data"))
}

Available options

Option	Comment	Default
WithFixtureDir	Set fixture dir name	testdata
WithNameSuffix	Suffix for fixture files.	.golden
WithDirPerms	Directory permissions for fixtures	0755
WithFilePerms	File permissions for fixtures	0644
WithDiffEngine	Diff engine to use for diff output	ClassicDiff
WithDiffFn	Custom diff logic to be used	None
WithIgnoreTemplateErrors	Ignore errors from templates	false
WithTestNameForDir	Create a folder with the tests name for the fixtures	false
WithSubTestNameForDir	Create a folder with the sub tests name for the fixtures	false

Diff output

golden has three output modes; classic diff (default), colored diffs and simple mode.

You can select your preferred output using the WithDiffEngine option:

g.New(
    t,
    golden.WithDiffEngine(golden.ColoredDiff), // Simple, ColoredDiff, ClassicDiff
)

New default fixture directory

There is a new default directory for fixtures, testdata. This directory is a better default as it is more widely used in the Go community (including the standard library).

New way to initialize golden

With the introduction of the functional options we also introduced golden.New, which is initializing golden. Assert* and other methods are now accessed like:

g := golden.New(t)
g.Assert(t, ...)

Contributing

First off, thanks for taking the time to contribute! Contributions are not only related to development. For example, GitHub Star motivates me to develop!

License

The golden project is licensed under the terms of MIT LICENSE. Original author is Sebastian Dahlgren.