mockhttp

Mock HTTP is a library for intercepting and matching requests made by http.Client and returning mock responses.

Like most mocking libraries, this library provides a set of reusable "matchers" that match HTTP requests and respond in a number of ways without involving an actual HTTP server. It's primarily useful for testing client applications as opposed to handlers, and was originally developed while building a REST client SDK.

Unlike a lot of other libraries, mockhttp doesn't ever use global state, nor does it muck around with things like http.DefaultClient. Instead, it works by providing a rule-evaluating http.Transport mocker (MockRoundTripper) which intercepts and processes requests. This design allows for parallel test execution without worrying about global state pollution or concurrency issues.

See the MockRoundTripper example for how to set up http.Client with a few rules. For information on the available matchers, see the Match*() convenience methods, and the matcher package. Responders also have convenience methods in the form RespondWith*() with implementations that live in the responder package.

Getting Started

Add mockhttp to your project:

go get -u http://github.com/esammer/mockhttp

Configure your http.Client with a MockRoundTripper transport:

// Create an http.Client, but use MockRoundTripper as the transport.
client := &http.Client{
    Transport: NewMockRoundTripper(
        // Add as many rules as you'd like. They're evaluated in order.
        // Rules contain a matcher and a responder.
        NewRule(MatchPath("/404"), RespondWithStatus(http.StatusNotFound)),

        NewRule(
            // Matchers can be combined into "all of" and "one of" expressions
            // for complex matching logic.
            MatchAllOf(
                PostMethodMatcher,
                MatchPath("/my-resource"),
            ),
            RespondWithBody(
                http.StatusInternalServerError,
                "application/json",
                `{ "things": [ "a", "b", "c" ] }`,
            ),
        ),
    ),
}

Make HTTP requests as you normally would. You'll get your mocked responses instead.

// Requests that match a rule will produce the mock response.
resp, err := client.Get("/")
if err != nil {
	// ...
}

fmt.Printf("Response: %+v\n", resp)

License

mockhttp is licensed under the Apache License 2.0.

See LICENSE for details.