GoMock Generator

gmg is type-safe, fast and handy alternative GoMock generator.

Features

• Up to 4x times faster than mockgen in reflect mode

  • mockgen builds program depending on your interface and analyse it with reflect - that is much extra work!
  • gmg loads ast and type info using go/packages which doesn't require build and run executable .

• Type-safe

  • gomock.Call wrapped so Do, Return and DoAndReturn arguments are concrete types, but just args ...interface{}
  • Autocomplete works perfect!
  • After mock regeneration all type inconsistency in tests are visible in IDE as type check errors.

• Robust

  • Generation usually works, even when compilation is not.

• Easy to use

  • There are sensible defaults for source package (.) and destination (./mocks).

    That is, usually, you need only to specify the interface name to mock.

Install

Go version >= 1.16

go install github.com/skipor/gmg@latest

Go version < 1.16

GO111MODULE=on go get github.com/golang/mock/mockgen@latest

Please fix a specific version, if you use gmg in automation.

Usage

$ gmg --help
gmg is type-safe, fast and handy alternative GoMock generator. See details at: https://github.com/skipor/gmg

Usage: gmg [--src <package path>] [--dst <file path>] [--pkg <package name>] <interface name> [<interface name> ...]

Flags:
      --all          Select all interfaces in package.
                     When called from //go:generate comment then package kind selected automatically: primary - other than *_test.go files; test - *_test.go files; black-box-test - package *_test

      --all-file     Select all interfaces in current file, when called from //go:generate comment .

      --debug        Verbose debug logging.
  -d, --dst string   Destination directory or file relative path or pattern.
                     '{}' in directory path will be replaced with the source package name.
                     '{}' in file name will be replaced with snake case interface name.
                     If no file name pattern specified, then '{}.go' used by default.
                     Examples:
                     	./mocks
                     	./{}mocks
                     	./mocks/{}_gomock.go
                     	./mocks_test.go # All mocks will be put to single file.
                      (default "./mocks")
  -p, --pkg string   Package name in generated files.
                     '{}' will be replaced with source package name.
                     By default, --dst package name used, or 'mocks_{}' if --dst package is not exist.
                     Examples:
                     	mocks_{} # mockgen style
                     	{}mocks # mockery style

  -s, --src string   Source Go package to search for interfaces. Absolute or relative.
                     Maybe third-party or standard library package.
                     Examples:
                     	.
                     	./relative/pkg
                     	github.com/third-party/pkg
                     	io
                      (default ".")
      --version      Show version and exit

Speed measures

• Large interface - 4x faster mockgen --destination ./mocks/interface.go k8s.io/client-go/kubernetes: 3.022 seconds gmg --src k8s.io/client-go/kubernetes Interface: 0.741 seconds
• Small interface - 2x faster mockgen --destination ./mocks/writer.go io Writer: 0.676 seconds gmg --src io Writer: 0.321 seconds

Measured on MacBook Pro (15-inch, 2017) 4 core i7, 16G with warm go build cache.