math-operations-e2e

Note: math-operations-e2e has been created as part of a practical demonstration for the blog post on Cross-Repo Triggers in GitHub Actions. The purpose of this repository is to showcase a real-world application of how to set up and utilize cross-repository triggers within GitHub Actions.

math-operations-e2e repository is dedicated to conducting comprehensive end-to-end (E2E) tests on the 'math-operations-dev' backend application. It is designed to be automatically triggered following the successful completion of unit tests in the parent repository, ensuring that new changes are verified in a scenario that closely emulates a production environment.

Repository Directory Structure

- .github/workflows       # Contains GitHub Actions E2E testing workflows
- node_modules            # Node.js project dependencies
- src                     # Source code for E2E testing
  - app.js                # Main entry point for the E2E testing application
  - math.operations.js    # Contains the mathematical operations to be tested
- tests                   # E2E test scripts for the application
  - math.operations.e2e.test.js
- .gitignore              # Lists files and directories to ignore in the repository
- package-lock.json       # Auto-generated file to lock down dependency versions
- package.json            # Project metadata and dependency manifest
- README.md               # Documentation for the repository

Workflow Activation

The E2E testing workflow, contained within math_operations_e2e.yml, is meticulously crafted to be initiated by a repository_dispatch event, sent from the math-operations-dev repository. The workflow includes steps to set up the testing environment, run the E2E tests.

Let's decipher the workflow file for the math-operations-e2e repository that defines the end-to-end (E2E) testing pipeline:

Workflow Breakdown

1. Workflow Trigger:

   on:
       repository_dispatch:
           types: [trigger-e2e-tests-event]

   This section sets the workflow to trigger on a repository_dispatch event specifically named trigger-e2e-tests-event. This event is dispatched by the parent repository, math-operations-dev, after the unit tests pass and the deployment step is echoed.

2. E2E Tests Job:

   jobs:
       e2e-tests:
           runs-on: ubuntu-latest

   The job e2e-tests is configured to run on the latest version of Ubuntu available in GitHub Actions. This ensures that the E2E tests are executed in a clean and updated environment.

   • Checkout Code:

     - name: Checkout E2E Test Repository Code
       uses: actions/checkout@v3

     This step uses the actions/checkout@v3 action to clone the math-operations-e2e repository code into the GitHub Actions runner, making it available for subsequent steps.

   • Set Up Node.js Environment:

     - name: Set Up Node.js Environment
       uses: actions/setup-node@v4
       with:
           node-version: "18"

     Here, the actions/setup-node@v4 action is used to set up a Node.js environment with version 18, which is required for running Node.js applications and their tests.

   • Install Dependencies:

     - name: Install E2E Testing Dependencies
       run: npm ci

     This command, npm ci, installs the dependencies defined in package-lock.json. It ensures a clean install of all the required packages for E2E testing, mirroring the exact versions as per the lock file.

   • Execute E2E Tests:

     - name: Execute End-to-End Tests
       run: npm run test

     The actual E2E tests are executed with the npm run test command. This script is defined in package.json and is responsible for running the test suite that validates the application's entire flow from end to end.

   • E2E Test Completion Notification:

     - name: E2E Test Completion Notification
       run: |
           echo "End-to-end testing has successfully completed. These tests validate the integrated functionality of the math operations backend in real-world scenarios, ensuring that the application performs as expected from start to finish."

     After the tests have completed, this step outputs a notification in the workflow logs. It serves as a confirmation that the E2E tests have run successfully, asserting that the application's workflow is functioning correctly in a simulated real-world environment.