gomock
Automatically generates mock code from a Go interface.
Status
This project is actively maintained. Commits are infrequent because it reached
a certain degree of stability and no additional features are needed at this time.
Installation
$ go install github.com/vibridi/gomock/v3@latest
Requirements:
Go 1.22.0
Usage
Type gomock help
for detailed usage tips. Mainly: gomock { help | [options] filename }
In short, it supports the following flags:
-f FILE
allows to specify the input file where your interface is declared. If not provided, it's assumed
the input file is the first argument after other options.
-o FILE
if set, tells the program to write the output to FILE
. Otherwise it just prints to stdout.
You can always capture the output with a pipe. E.g. if you are on MacOS, you could do gomock -f myfile.go | pbcopy
-i IDENTIFIER
if the input file contains more than one interface declaration, you can use the -i
flag to tell the program which one to parse.
If not set, the program defaults to the first encountered interface.
-x
if set, static functions are exported (usually those whose name begins with with
and new
)
-u
if set, allows to output default functions and With*
functions with unnamed arguments.
--local
if set, doesn't qualify output mock types with the package name. It qualifies them by default.
The default behavior is to always output named arguments, as some IDEs reference them in code completion.
--struct
if set, prints the output in struct style, instead of options style (see below for further details).
--name NAME
allows to override the interface name used in output types with NAME
.
--utype MAPPING [ --utype MAPPING ]
allows to manually specify the underlying type of a named type.
--help, -h
prints a help message.
--version, -v
prints the version number.
Breaking changes from version 2.x
- The option
-q
is removed. It's assumed that mocked types are always qualified with their package name.
The option --local
can be used instead to opt out (i.e. to not qualify them).
- The option
--struct-type
has been renamed to --struct
. It has the same effect.
Features
This tool is able to resolve composed interfaces, however all declarations must live
in the same directory or sub-directories relative to the main file. To see this in action, run make example-compose
.
Example (options style)
To try out the tool after cloning the repo:
$ make build
$ ./build/gomock -f _example/_example.go
It will print out the generated mock code, with the options pattern:
type mockTestInterface struct {
options mockTestInterfaceOptions
}
type mockTestInterfaceOptions struct {
funcGet func() string
funcSet func(v string)
}
var defaultMockTestInterfaceOptions = mockTestInterfaceOptions{
funcGet: func() string {
return ""
},
funcSet: func(string) {
return
},
}
type mockTestInterfaceOption func(*mockTestInterfaceOptions)
func withFuncGet(f func() string) mockTestInterfaceOption {
return func(o *mockTestInterfaceOptions) {
o.funcGet = f
}
}
func withFuncSet(f func(string) ) mockTestInterfaceOption {
return func(o *mockTestInterfaceOptions) {
o.funcSet = f
}
}
func (m *mockTestInterface) Get() string {
return m.options.funcGet()
}
func (m *mockTestInterface) Set(v string) {
return
}
func newMockTestInterface(opt ...mockTestInterfaceOption) TestInterface {
opts := defaultMockTestInterfaceOptions
for _, o := range opt {
o(&opts)
}
return &mockTestInterface{
options: opts,
}
}
Then you can use the generated code in your unit tests:
myMock := newMockTestInterface(
withFuncGet(f func() string {
return "test-value"
}),
)
myMock.Get() // "test-value"
objectThatUsesTestInterface := NewObject(myMock)
// ...
Example (struct style)
To print the mock code in struct style, run:
$ make build
$ ./build/gomock -f _example/_example.go --struct-style
And it will print:
type mockTestInterface struct {
GetFunc func() string
SetFunc func(v string)
}
func (m *mockTestInterface) Get() string {
if m.GetFunc != nil {
return m.GetFunc()
}
return ""
}
func (m *mockTestInterface) Set(v string) {
if m.SetFunc != nil {
m.SetFunc(v)
}
}
Authors
Currently there are no other contributors
TODOs
- Remove extra space between signature and
{
when the function has no return types
License
This project is licensed under the MIT License - see the LICENSE.md file for details