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https://github.com/matryer/moq
Interface mocking tool for go generate
https://github.com/matryer/moq
codegen golang mocking testing
Last synced: 3 days ago
JSON representation
Interface mocking tool for go generate
- Host: GitHub
- URL: https://github.com/matryer/moq
- Owner: matryer
- License: mit
- Created: 2016-08-29T10:00:17.000Z (over 8 years ago)
- Default Branch: main
- Last Pushed: 2024-08-24T05:25:26.000Z (4 months ago)
- Last Synced: 2024-10-29T15:40:08.261Z (about 1 month ago)
- Topics: codegen, golang, mocking, testing
- Language: Go
- Homepage: http://bit.ly/meetmoq
- Size: 2.39 MB
- Stars: 1,980
- Watchers: 17
- Forks: 126
- Open Issues: 25
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
- awesome-go - moq - Utility that generates a struct from any interface. The struct can be used in test code as a mock of the interface. (Testing / Mock)
- awesome-go - moq - Utility that generates a struct from any interface. The struct can be used in test code as a mock of the interface. Stars:`2.0K`. (Testing / Mock)
README
 [](https://github.com/matryer/moq/actions?query=branch%3Amaster) [](https://goreportcard.com/report/github.com/matryer/moq)
Interface mocking tool for go generate.
### What is Moq?
Moq is a tool that generates a struct from any interface. The struct can be used in test code as a mock of the interface.
above: Moq generates the code on the right.
You can read more in the [Meet Moq blog post](http://bit.ly/meetmoq).
### Installing
To start using latest released version of Moq, just run:
```
$ go install github.com/matryer/moq@latest
```
Note that Go 1.18+ is needed for installing from source. For using Moq with
older Go versions, use the pre-built binaries published with
[Moq releases](https://github.com/matryer/moq/releases).
### Usage
```
moq [flags] source-dir interface [interface2 [interface3 [...]]]
-fmt string
go pretty-printer: gofmt, goimports or noop (default gofmt)
-out string
output file (default stdout)
-pkg string
package name (default will infer)
-rm
first remove output file, if it exists
-skip-ensure
suppress mock implementation check, avoid import cycle if mocks generated outside of the tested package
-stub
return zero values when no mock implementation is provided, do not panic
-version
show the version for moq
-with-resets
generate functions to facilitate resetting calls made to a mock
Specifying an alias for the mock is also supported with the format 'interface:alias'
Ex: moq -pkg different . MyInterface:MyMock
```
**NOTE:** `source-dir` is the directory where the source code (definition) of the target interface is located.
It needs to be a path to a directory and not the import statement for a Go package.
In a command line:
```
$ moq -out mocks_test.go . MyInterface
```
In code (for go generate):
```go
package my
//go:generate moq -out myinterface_moq_test.go . MyInterface
type MyInterface interface {
Method1() error
Method2(i int)
}
```
Then run `go generate` for your package.
### How to use it
Mocking interfaces is a nice way to write unit tests where you can easily control the behaviour of the mocked object.
Moq creates a struct that has a function field for each method, which you can declare in your test code.
In this example, Moq generated the `EmailSenderMock` type:
```go
func TestCompleteSignup(t *testing.T) {
var sentTo string
mockedEmailSender = &EmailSenderMock{
SendFunc: func(to, subject, body string) error {
sentTo = to
return nil
},
}
CompleteSignUp("[email protected]", mockedEmailSender)
callsToSend := len(mockedEmailSender.SendCalls())
if callsToSend != 1 {
t.Errorf("Send was called %d times", callsToSend)
}
if sentTo != "[email protected]" {
t.Errorf("unexpected recipient: %s", sentTo)
}
}
func CompleteSignUp(to string, sender EmailSender) {
// TODO: this
}
```
The mocked structure implements the interface, where each method calls the associated function field.
## Tips
* Keep mocked logic inside the test that is using it
* Only mock the fields you need
* It will panic if a nil function gets called
* Name arguments in the interface for a better experience
* Use closured variables inside your test function to capture details about the calls to the methods
* Use `.MethodCalls()` to track the calls
* Use `.ResetCalls()` to reset calls within an individual mock's context
* Use `go:generate` to invoke the `moq` command
* If Moq fails with a `go/format` error, it indicates the generated code was not valid.
You can run the same command with `-fmt noop` to print the generated source code without attempting to format it.
This can aid in debugging the root cause.
## License
The Moq project (and all code) is licensed under the [MIT License](LICENSE).
Moq was created by [Mat Ryer](https://twitter.com/matryer) and [David Hernandez](https://github.com/dahernan), with ideas lovingly stolen from [Ernesto Jimenez](https://github.com/ernesto-jimenez). Featuring a major refactor by @sudo-suhas, as well as lots of other contributors.
The Moq logo was created by [Chris Ryer](http://chrisryer.co.uk) and is licensed under the [Creative Commons Attribution 3.0 License](https://creativecommons.org/licenses/by/3.0/).