serverless-offline-http-mock

Overview

This is a plugin for the serverless framework that provides the ability to create mock responses to HTTP(S) requests. This is useful when developing integration against an API spec that doesn't yet exist. This plugin uses nock to provide mock responses. It supports mock requests for:

• Local Invoke Lambda calls
• Serverless Offline API Gateway Lambda calls
• Serverless Appsync Offline data sources

Requirements

A serverless framework project that uses useInProcess to run Lambda handlers.

Running handlers in worker threads or Docker containers is not supported.

In order to intercept HTTP calls when using serverless-offline worker threads or Docker containers, you must go the old-school route and manually return mock data in your code.

Installation

npm install serverless-offline-http-mock

OR

yarn add serverless-offline-http-mock

Upgrade to v1.0.0

Please note that if you installed a version of this prior to v1.0.0, you will need to follow step #2 below and add a truthy serverless-offline-http-mock-enabled value in order for your mocks to be loaded.

Usage

1. Within the serverless.yml file, enable the plugin by placing an serverless-offline-http-mock entry in the plugins section. If using Serverless Offline, make sure it is placed above the serverless-offline plugin

2. Create a serverless-offline-http-mock-enabled entry in the custom section with a truthy (true, 1, etc) or falsy value (false, 0, etc). You can also use environment variables (for example, ${env:MOCK_ENABLED}).

3. Create a serverless-offline-http-mock entry in the custom section.

4. For each host, create an entry containing hostname, a list of JS files to load, and an optional directory. See serverless.yml example below.

5. In each JS file, export a function that accepts the nock library and hostname as arguments. Within that function, implement nock to handle the HTTP(S) requests. See example.js example below.

Example

serverless.yml:

...
custom:
  serverless-offline-http-mock-enabled: 1
  serverless-offline-http-mock:
    - hostname: http://www.example.com
      directory: 'mocks' # Optional
      mocks:
        - example.js

plugins:
  - serverless-offline-http-mock # Note how this comes before serverless-offline
  - serverless-offline

mocks/example.js:

const mocks = (nock, hostname) =>
  nock(hostname)
    .persist()
    .get('/')
    .reply(200, 'success!');
module.exports = mocks;

Development

yarn test