Faux

Generates fakes for use in testing Go programs.

Usage

faux helps you generate fakes

Usage: faux --file <FILE> --output <FILE> --interface <INTERFACE-TO-FAKE> [--help]

Flags:
  --file, -f, GOFILE  string  the name of the file to parse
  --help, -h          bool    prints the usage
  --interface, -i     string  the name of the interface to fake
  --name, -n          string  the name to give the generated type
  --output, -o        string  the name of the file to write
  --package, -p       string  the name of the package that contains the interface
  --version, -v       bool    prints the version

Example

Say I have an interface in my codebase that I would like to generate a fake for. I can add a go:generate comment like the following to generate a fake.

package main

//go:generate faux -i SomeInterface -o fakes/some_interface.go
type SomeInterface interface {
  SomeMethod(someParam bool) (someResult int)
}

This will output a fakes/some_interface.go file with the following contents.

package fakes

type SomeInterface struct {
  SomeMethodCall struct {
    CallCount int
    Receives  struct {
      SomeParam bool
    }
    Returns struct {
      SomeResult int
    }
  }
}

func (f *SomeInterface) SomeMethod(someParam bool) int {
  f.SomeMethodCall.CallCount++
  f.SomeMethodCall.Receives.SomeParam = someParam
  return f.SomeMethodCall.Returns.SomeResult
}

Installation

To download faux go to Releases.

Alternatively, you can install faux via homebrew

brew tap ryanmoran/tools
brew install faux

You can also build from source.

Building from Source

You'll need at least Go 1.11, as faux uses Go Modules to manage dependencies.

To build from source, after you've cloned the repo, run these commands from the top level of the repo:

GO111MODULE=on go mod download
GO111MODULE=on go build

Go 1.11 uses some heuristics to determine if Go Modules should be used. The process above overrides those herusitics to ensure that Go Modules are always used. If you have cloned this repo outside of your GOPATH, GO111MODULE=on can be excluded from the above steps.