Pretend-Boot

Typically I write tests to make sure my API is sane, and I write tests to make sure my JS behaves appropriately given the API is sane. But I end up writing feature tests that seem redundant, based on fear that I'm going to break the contract on either the server side or the client side.

My intention with this library is to be able to easily capture actual behavior of my API for me to run my js tests against, without having to spin up an entire server. Every time I change my java code I can know whether or not I've broken an assumption my JS code makes, and vise versa.

Usage

1. Capture some requests

Add a BehaviorRecordingResultHandler to an existing API test that you'd like to treat as a fixture on the javascript side.

@Test
public void someExistingApiTestIWantToExposeToJavascript() {
    this.mockMvc.perform(
                MockMvcRequestBuilders.get("/something"))
                    .andDo(saveFixture("js/spec/behavior"))
                .andExpect(...);
}

(see src/test/java/RecordingTest.java)

You can do this to as many tests as you want.

2. Make those request fixtures available to tests

const loadApiBehavior = require('./loadApiBehavior');

module.exports = {
    ...,
    plugins: [new webpack.DefinePlugin({
        API_BEHAVIOR: JSON.stringify(loadApiBehavior("./spec/behavior"))
    })]
};

(see js/webpack.config.js)

3. Activate your fixtures in your integration tests

    let pretendBoot = new PretendBoot();

    beforeEach(() => {
        pretendBoot.start(API_BEHAVIOR);
    });

    afterEach(() => {
        pretendBoot.stop();
    });
    
    it("can now act as though our API is running!", () => {
        /* if I make a request to one of the endpoints specified in spec/behavior,
           I should get the response I captured earlier */
    });    

(see js/spec/integration_spec.js)

4. Write fewer feature tests!

While pretend-boot is activated your JS tests can pretend your real server is running, without many of the costs associated with feature tests!

TODO

• try it from an application
• Publish to npm
• Publish to maven
• Probably other stuff too