[![GoDoc](https://godoc.org/github.com/smartystreets/assertions/internal/oglemock?status.svg)](https://godoc.org/github.com/smartystreets/assertions/internal/oglemock)

`oglemock` is a mocking framework for the Go programming language with the
following features:

 *  An extensive and extensible set of matchers for expressing call
    expectations (provided by the [oglematchers][] package).

 *  Clean, readable output that tells you exactly what you need to know.

 *  Style and semantics similar to [Google Mock][googlemock] and
    [Google JS Test][google-js-test].

 *  Seamless integration with the [ogletest][] unit testing framework.

It can be integrated into any testing framework (including Go's `testing`
package), but out of the box support is built in to [ogletest][] and that is the
easiest place to use it.


Installation
------------

First, make sure you have installed Go 1.0.2 or newer. See
[here][golang-install] for instructions.

Use the following command to install `oglemock` and its dependencies, and to
keep them up to date:

    go get -u github.com/smartystreets/assertions/internal/oglemock
    go get -u github.com/smartystreets/assertions/internal/oglemock/createmock

Those commands will install the `oglemock` package itself, along with the
`createmock` tool that is used to auto-generate mock types.


Generating and using mock types
-------------------------------

Automatically generating a mock implementation of an interface is easy. If you
want to mock interfaces `Bar` and `Baz` from package `foo`, simply run the
following:

    createmock foo Bar Baz

That will print source code that can be saved to a file and used in your tests.
For example, to create a `mock_io` package containing mock implementations of
`io.Reader` and `io.Writer`:

    mkdir mock_io
    createmock io Reader Writer > mock_io/mock_io.go

The new package will be named `mock_io`, and contain types called `MockReader`
and `MockWriter`, which implement `io.Reader` and `io.Writer` respectively.

For each generated mock type, there is a corresponding function for creating an
instance of that type given a `Controller` object (see below). For example, to
create a mock reader:

```go
someController := [...]  // See next section.
someReader := mock_io.NewMockReader(someController, "Mock file reader")
```

The snippet above creates a mock `io.Reader` that reports failures to
`someController`. The reader can subsequently have expectations set up and be
passed to your code under test that uses an `io.Reader`.


Getting ahold of a controller
-----------------------------

[oglemock.Controller][controller-ref] is used to create mock objects, and to set
up and verify expectations for them. You can create one by calling
`NewController` with an `ErrorReporter`, which is the basic type used to
interface between `oglemock` and the testing framework within which it is being
used.

If you are using [ogletest][] you don't need to worry about any of this, since
the `TestInfo` struct provided to your test's `SetUp` function already contains
a working `Controller` that you can use to create mock object, and you can use
the built-in `ExpectCall` function for setting expectations. (See the
[ogletest documentation][ogletest-docs] for more info.) Otherwise, you will need
to implement the simple [ErrorReporter interface][reporter-ref] for your test
environment.


Documentation
-------------

For thorough documentation, including information on how to set up expectations,
see [here][oglemock-docs].


[controller-ref]: http://godoc.org/github.com/smartystreets/assertions/internal/oglemock#Controller
[reporter-ref]: http://godoc.org/github.com/smartystreets/assertions/internal/oglemock#ErrorReporter
[golang-install]: http://golang.org/doc/install.html
[google-js-test]: http://code.google.com/p/google-js-test/
[googlemock]: http://code.google.com/p/googlemock/
[oglematchers]: https://github.com/smartystreets/assertions/internal/oglematchers
[oglemock-docs]: http://godoc.org/github.com/smartystreets/assertions/internal/oglemock
[ogletest]: https://github.com/smartystreets/assertions/internal/ogletest
[ogletest-docs]: http://godoc.org/github.com/smartystreets/assertions/internal/ogletest
