How to create a mock response

If you need a server-side resource or service which doesn't yet exist or is out of reach, the goal of mocks is to enable you to quickly create one.

If you have lws-mock-response present in your stack (included by default) you will have the option to set --mocks.

$ ws --mocks my-mocks-module.js

Here is the minimum code required for a mock module, you can use this as a boilerplate template. Replace MyMockModule with a more useful name.

module.exports = MockBase => class MyMockModule extends MockBase {
  mocks () {
  }
}

The mocks method must return an object with two properties - route and responses. The route value can use any Express-style routing syntax, described here in the "Route paths" and "Route parameters" sections.

module.exports = MockBase => class MyMockModule extends MockBase {
  mocks () {
    return {
      route: '/pizzas/:id',
      responses: []
    }
  }
}

The responses property must contain one or more objects, each with a response property. The response property value will be written directly to the Koa ctx object, meaning on this object you can set any of the standard ctx response values. The properties you will set must commonly are body, status and type.

This example will respond with 200 (the default statusCode) and the body Margerita to any request for /pizzas/:id, e.g. /pizzas/1.

module.exports = MockBase => class MyMockModule extends MockBase {
  mocks () {
    return {
      route: '/pizzas/:id',
      responses: [
        {
          response: {
            body: 'Margerita'
          }
        }
      ]
    }
  }
}