Mocking API services in development and testing with Wiremock

This repo contains the sample application for Mocking API services in development and testing with Wiremock guide on Docker Docs. This project first demonstrates how to integrate the AccuWeather API with a Node.js server to fetch and display weather data for a given city. To simulate the weather API, you'll use WireMock that enables you to mock API responses during development and testing.

Project Overview

This project is divided into two main steps:

1. AccuWeather API Integration:

• Test the integration between your Node.js server and the AccuWeather API to ensure that your server correctly makes requests to the AccuWeather API and handles the responses.

2. Mocking with WireMock:

• Use WireMock to mock the AccuWeather API by creating a stub response. This allows you to test your Node.js server without making actual requests to the AccuWeather API.

Notice: This sample repo is intended to support the guide mentioned above. As such, the application code is purposely kept simple to keep the focus on the guide's content and should not be considered production-ready.

Tech Stack

• Node.js: A JavaScript runtime environment for building server-side applications.
• Express: A popular web application framework for Node.js.
• Axios: A promise-based HTTP client for making requests to external APIs.
• Dotenv: A zero-dependency module that loads environment variables from a .env file.
• WireMock: A tool for stubbing and mocking HTTP requests during testing.

Prerequisite

• Docker Desktop
• Node (LTS version)
• AccuWeather API Key - You will need to create a free account and download it from here.

Scenario 1: A Real AccuWeather API Integration

Follow the below step to set up a Node.js application to fetch the weather data from the real AccuWeather API.

1. Clone the repository:

git clone https://github.com/ajeetraina/wiremock-node-docker

2. Navigate to the accuweather-api directory:

cd accuweather-api

3. Set the Environment Variable:

To use AccuWeather API, set the following envrionment variable:

export USE_WIREMOCK=false

4. Create a .env file

Create a .env file in the root directory of the project and add your AccuWeather API key:

ACCUWEATHER_API_KEY=2gzXXXXXXXBWnZU

5. Run the project

npm install
npm run start

You should see the following output:

> [email protected] start
> node src/index.js

Listening: http://localhost:5000
Stub created successfully!

Keep this terminal window open.

6. Testing the application

Open a new terminal and run the following curl command to test the application:

curl "http://localhost:5000/api/v1/getWeather?city=Bengaluru"

The response should look like this:

{"city":"Bengaluru","temperature":27.1,"conditions":"Mostly cloudy","forecasts":[{"date":"2024-09-02T07:00:00+05:30","temperature":83,"conditions":"Partly sunny w/ t-storms"},{"date":"2024-09-03T07:00:00+05:30","temperature":83,"conditions":"Thunderstorms"},{"date":"2024-09-04T07:00:00+05:30","temperature":83,"conditions":"Intermittent clouds"},{"date":"2024-09-05T07:00:00+05:30","temperature":82,"conditions":"Dreary"},{"date":"2024-09-06T07:00:00+05:30","temperature":82,"conditions":"Dreary"}]}%

Switch back to the terminal where you ran npm run start and you will see the following output:

Location Response: [
  {
    Version: 1,
    Key: '204108',
    Type: 'City',
    Rank: 11,
    LocalizedName: 'Bengaluru',
    EnglishName: 'Bengaluru',
    PrimaryPostalCode: '',
    Region: { ID: 'ASI', LocalizedName: 'Asia', EnglishName: 'Asia' },
    Country: { ID: 'IN', LocalizedName: 'India', EnglishName: 'India' },
    AdministrativeArea: {
      ID: 'KA',
      LocalizedName: 'Karnataka',
      EnglishName: 'Karnataka',
      Level: 1,
      LocalizedType: 'State',
      EnglishType: 'State',
      CountryID: 'IN'
    },
    TimeZone: {
      Code: 'IST',
      Name: 'Asia/Kolkata',
      GmtOffset: 5.5,
      IsDaylightSaving: false,
      NextOffsetChange: null
    },
    GeoPosition: { Latitude: 12.991, Longitude: 77.579, Elevation: [Object] },
    IsAlias: false,
    SupplementalAdminAreas: [ [Object] ],
    DataSets: [
      'AirQualityCurrentConditions',
      'AirQualityForecasts',
      'Alerts',
      'FutureRadar',
      'MinuteCast',
      'PremiumAirQuality'
    ]
  }
]
GET /api/v1/getWeather?city=Bengaluru 200 1690.639 ms - 500

Scenario 2: Running Wiremock in a Docker container

WireMock acts as the mock API that your backend will communicate with to retrieve data. The mock API responses have already been created for you in the mappings directory.

1. Navigate to the wiremock-endpoint directory:

cd wiremock-endpoint

2. Run the Wiremock service:

docker compose up -d

Verify if the WireMock container is running via Docker Dashboard.

3. Check the logs using the Docker Dashboard

4. Testing the mock APIs

curl http://localhost:8080/api/v1/getWeather\?city\=Bengaluru

The response should be:

{"city":"Bengaluru","temperature":25,"conditions":"Clear Sky"}

Scenario 3: Connecting non-containerised Nodejs to a containerised Wiremock

Based on your getWeather.js file, here's how you can adjust your Node.js server to toggle between fetching data from the real AccuWeather API and using the mocked responses provided by WireMock.

1. Navigate back to accuweather-api directory and run the following command to switch to Wiremock.

export USE_WIREMOCK=true

2. Start the Node application

npm run start

3. Testing the Mock API

curl "http://localhost:8080/api/v1/getWeather?city=Bengaluru"

You will see the following result:

{"city":"Bengaluru","temperature":25,"conditions":"Clear Sky"}%