A simple OKHttp client mock, using a programmable request interceptor

Import

On your build.gradle add:

dependencies {
    testImplementation 'com.github.gmazzo.okhttp.mock:mock-client:<version>'
}

Usage

Create an OkHttp request interceptor and record some rules, for instance:

val interceptor = MockInterceptor().apply {

    rule(get or post or put, url eq "https://testserver/api/login") {
        respond(HTTP_401_UNAUTHORIZED).header("WWW-Authenticate", "Basic")
    }

    rule(url eq "https://testserver/api/json") {
        respond("{succeed:true}", MEDIATYPE_JSON)
    }

    rule(url eq "https://testserver/api/json") {
        respond(resource("sample.json"), MEDIATYPE_JSON)
    }

    rule(path matches "/aPath/(\\w+)".toRegex(), times = anyTimes) {
        respond { body("Path was " + it.url().encodedPath()) }
    }

    rule(delete) {
        respond(code = HTTP_405_METHOD_NOT_ALLOWED) {
            body("{succeed:false}", MEDIATYPE_JSON)
        }
    }

    // throw an exception
    rule(get) {
        respond { throw IllegalStateException("an IO error") }
    }

}

Or in Java:

MockInterceptor interceptor = new MockInterceptor();

interceptor.addRule()
        .get().or().post().or().put()
        .url("https://testserver/api/login")
        .respond(HTTP_401_UNAUTHORIZED)
        .header("WWW-Authenticate", "Basic");

interceptor.addRule()
        .get("https://testserver/api/json")
        .respond("{succeed:true}", MEDIATYPE_JSON);

interceptor.addRule()
        .get("https://testserver/api/json")
        .respond(resource("sample.json"), MEDIATYPE_JSON);

interceptor.addRule()
        .pathMatches(Pattern.compile("/aPath/(\\w+)"))
        .anyTimes()
        .answer(request -> new Response.Builder()
            .code(200)
            .body(ResponseBody.create(null, "Path was " + request.url().encodedPath())));

Then add the interceptor to your OkHttpClient client and use it as usual:

OkHttpClient client = new OkHttpClient.Builder()
                .addInterceptor(interceptor)
                .build();

Check an example Integration Test with mocked HTTP responses

You can use the following helper classes to provide mock responses from resources:

• ClasspathResources.resource to load content from classpath
• AndroidResources.asset to load content from an Android's asset
• AndroidResources.rawRes to load content from an Android's raw resource
• RoboResources.asset and RoboResources.rawRes if you are running Roboelectric tests