×
Alex Knight

Orchestrating Web Server Integration Tests Using npm

Written by Ken Dale
2
This post is days old.

It can be tricky to run integration tests targeting a web server using the command line. Essentially, we need to:

  • Start the application
  • Wait for the application to be ready (begin responding to requests)
  • Run integration tests
  • Terminate the server after test run is complete

We can do all of this with a simple npm script:

package.json

{
  "scripts": {
    "integration-tests": "concurrently -k -s first \"npm start\" \"wait-on http://localhost:8081/ && COMMAND_TO_RUN_HERE\""
  }
}

And run the script:

> npm run integration-tests

Let’s break down how it works

The concurrently npm package uses these arguments:

  • -k (or --kill-others): kill other processes if one exits or dies
    • After the test run concludes we terminate the web server too.
  • -s first (or --success first): Return exit code of zero or one based on the success or failure of the “first” child to terminate, the “last child”, or succeed only if “all” child processes succeed. [choices: “first”, “last”, “all”] [default: “all”]
    • Since the tests will terminate before the web server the exit code of the tests will be returned.
  • List each item to execute – the commands for starting the web server and running the integration tests. Since we are inside a JSON string we can escape the inner double quotes with \".
    • We want the tests to run after the web server has started up and is responding to requests. We can use the wait-on npm package to wait for a url to start working. Adjust the http://localhost:8081/ in the script as needed.

Final note

Lastly, don’t forget to npm install concurrently wait-on --save-dev into your project! Happy testing!

Ken Dale
Ken Dale
Senior Application Developer
JavaScript
npm
Suggested reading

Vue Group Transitions

JavaScript
Simple transitions Vue.js has an extremely helpful was to handle animations ...
Read now

Vue CLI Environment Variables

JavaScript
In development it is common to not want to share everything in our code. Thin...
Read now

Computed Side Effects in Vue.js

JavaScript
In Vue computed properties are a life saver when it comes to being able to ad...
Read now

Global State versus Component State

JavaScript
State management, Redux, Vuex… whatever you want to call it or whatever flavo...
Read now

The Key to the Vue v-for

JavaScript
If you’re familiar with Vue at all, you’re probably familiar with the v-for. ...
Read now

Using Environment Variables with Jekyll, Vue.js, and Netlify

JavaScript
We operate in a typical QA -> Production workflow on both our front-end an...
Read now

Comments

Stay fresh! The brighter green, the fresher the article!