Running Mocha Chai Tests via Gitlab CI

This article demonstrates how we can run Mocha Chai tests in Gitlab CI Pipeline. In this article, I will go through the step-by-step starting with setting up the test project and the pipeline. Before that, it’s great to start by getting a better understanding of Mocha, Chai, and Gitlab.

What is Mocha Chai?

In software testing, Mocha and Chai are actually two separate testing frameworks for JavaScript. Mocha is a JavaScript testing framework that provides a structure for organizing and running tests, while Chai is an assertion library that provides a set of functions for writing more expressive and understandable assertions.

Mocha and Chai can be used to create and run automated tests for JavaScript code. Mocha provides a framework for writing and organizing test suites, while Chai provides the functions for asserting the behavior of the code being tested.

What is GitLab?

GitLab is a web-based Git repository manager that provides source code management, continuous integration and deployment, issue tracking, and more. It is a complete DevOps platform that enables developers to collaborate on code, test and deploy applications, and monitor their performance.

GitLab is built on top of Git, which is a distributed version control system that allows developers to manage and track changes to their code over time. GitLab provides a web-based interface that makes it easy for developers to work with Git and collaborate with other team members.

Some of the features provided by GitLab include:

• Git repository management with support for branching, merging, and versioning
• Issue tracking and project management tools
• Continuous integration and deployment pipelines
• Code review and collaboration tools
• Monitoring and analytics tools for tracking application performance and usage

GitLab can be installed on-premises or used as a cloud-based service, and it is available in both free and paid versions, with the paid versions providing additional features and support.

Pre-requisites

1. Gitlab account
2. Node.js downloaded and installed. Reference: link

Setup Mocha Chai Test

1. Create a new folder for your new project. Within the new folder, using terminal, install dependencies for Mocha, Chai, and Mocha Junit Reporter.

npm install mocha chai mocha-junit-reporter --save-dev

2. Create a simple test file for example called basicOperation.spec.js

const assert = require('assert');

describe('Mathematical Operations - Test Suite', function() {
    this.timeout(500);
    const a = 20;
    const b = 10;

    it('Addition of two variables', function(done) {
        this.timeout(300);
        setTimeout(done,100);
        const c = a+b;
        assert.equal(c,30);
    });
    
    it('Substraction of two variables', function() {
        const c = a-b;
        assert.equal(c,10);
    });

    it('Multiplication of two variables', function() {
        const c = a*b;
        assert.equal(c,200);
    });

    it('Division of two variables', function() {
        const c = a/b;
        assert.equal(c,2);
    });
});

Within the package.json file, add the following configs:

{
  "scripts": {
    "test": "mocha '**/*.spec.js' --reporter mocha-junit-reporter --reporter-options mochaFile=junit.xml"
  },
  "devDependencies": {
    "chai": "^4.3.7",
    "mocha": "^10.2.0",
    "mocha-junit-reporter": "^2.2.0"
  }
}

Setup Pipeline

Create a file called .gitlab-ci.yml and set up test stages. The following config will allow you to use the default Gitlab runner and store the junit.xml report as the pipeline artifact.

image: node:latest

cache:
  paths:
    - node_modules/

stages:
  - test

test:
  stage: test
  script:
    - npm install
    - npm test
  artifacts:
    when: always
    reports:
      junit:
        - junit.xml

Push your project into a Gitlab project. Your test project directory will look something like this once everything has been set up. The project name in this example is called mocha-basic.

Run your pipeline and within the pipelines report, you should be able to see the following test report.

Test summary

Test job log