GoMock is a mocking framework for the Go programming language. It integrates well with Go's built-in
testing package, but can be used in other contexts too.
Once you have installed Go, run these commands to install the
gomock package and the
go get github.com/golang/mock/gomock go install github.com/golang/mock/mockgen
After installing, you can use
go doc to get documentation:
go doc github.com/golang/mock/gomock
Alternatively, there is an online reference for the package hosted on GoPkgDoc here.
mockgen has two modes of operation: source and reflect. Source mode generates mock interfaces from a source file. It is enabled by using the -source flag. Other flags that may be useful in this mode are -imports and -aux_files.
mockgen -source=foo.go [other options]
Reflect mode generates mock interfaces by building a program that uses reflection to understand interfaces. It is enabled by passing two non-flag arguments: an import path, and a comma-separated list of symbols.
mockgen database/sql/driver Conn,Driver
mockgen command is used to generate source code for a mock class given a Go source file containing interfaces to be mocked. It supports the following flags:
-source: A file containing interfaces to be mocked.
-destination: A file to which to write the resulting source code. If you don't set this, the code is printed to standard output.
-package: The package to use for the resulting mock class source code. If you don't set this, the package name is
mock_ concatenated with the package of the input file.
-imports: A list of explicit imports that should be used in the resulting source code, specified as a comma-separated list of elements of the form
bar/baz is the package being imported and
foo is the identifier to use for the package in the generated source code.
-aux_files: A list of additional files that should be consulted to resolve e.g. embedded interfaces defined in a different file. This is specified as a comma-separated list of elements of the form
bar/baz.go is the source file and
foo is the package name of that file used by the -source file.
-build_flags: (reflect mode only) Flags passed verbatim to
-mock_names: A list of custom names for generated mocks. This is specified as a comma-separated list of elements of the form
Repository is the interface name and
MockSensorRepository is the desired mock name (mock factory method and mock recorder will be named after the mock). If one of the interfaces has no custom name specified, then default naming convention will be used.
For an example of the use of
mockgen, see the
sample/ directory. In simple cases, you will need only the
TODO: Brief overview of how to create mock objects and set up expectations, and an example.