Objective

A repository at /home/interview/repo contains a Node.js application with a test suite that needs to be tested across multiple Node.js versions (18, 20, and 22). The repository has the upload-artifact action available locally at .github/actions/upload-artifact.

Task

Complete the workflow at .github/workflows/pr-tests.yml that runs the test suite across Node.js versions 18, 20, and 22 using a matrix strategy with container images (node:${{ matrix.node-version }}-slim). Each matrix job should create a node-version.txt file containing its Node.js version number and upload it as an artifact named node-<version>-version (e.g., node-18-version) using the local upload-artifact action. The workflow should trigger on pull requests.

File Path

• Workflow: /home/interview/repo/.github/workflows/pr-tests.yml
• Test suite: /home/interview/repo/run-tests.sh

name: Matrix Test

on:
  pull_request:

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: [18, 20, 22]
    container:
      image: node:${{ matrix.node-version }}-slim

    steps:
      - uses: actions/checkout@v4

      - name: Run tests
        run: ./run-tests.sh

      - name: Create version artifact
        run: echo "${{ matrix.node-version }}" > node-version.txt

      - name: Upload artifact
        uses: ./.github/actions/upload-artifact
        with:
          name: node-${{ matrix.node-version }}-version
          path: node-version.txt

Explanation

Step 1: Matrix Strategy

strategy:
  matrix:
    node-version: [18, 20, 22]

This tells GitHub Actions to run the same job three times, once for each value in the array. Each run gets its own matrix.node-version variable (18, 20, or 22). The jobs run in parallel by default.

Step 2: Container Image

container:
  image: node:${{ matrix.node-version }}-slim

Instead of installing Node.js on the runner, we run the entire job inside a Docker container with Node.js pre-installed. node:18-slim, node:20-slim, and node:22-slim are official Node.js images. This is faster and more reliable than using setup actions.

Step 3: Per-Version Artifacts

- name: Create version artifact
  run: echo "${{ matrix.node-version }}" > node-version.txt

- name: Upload artifact
  uses: ./.github/actions/upload-artifact
  with:
    name: node-${{ matrix.node-version }}-version
    path: node-version.txt

Each matrix job writes its version number to node-version.txt and uploads it with a unique name (node-18-version, node-20-version, node-22-version). The unique name prevents matrix jobs from overwriting each other's artifacts.