CI/CD pipeline basics in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a basic GitHub Actions workflow that triggers on push.

Node.js

name: Node.js CI
on: [1]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3

Drag options to blanks, or click blank then click option'

Arelease

Bschedule

Cpush

Dpull_request

Attempts:

3 left

💡 Hint

Common Mistakes

Using pull_request instead of push triggers workflow on PRs, not pushes.

The push event triggers the workflow when code is pushed to the repository.

2fill in blank

medium

Complete the code to add a step that installs Node.js dependencies using npm.

Node.js

    steps:
      - uses: actions/checkout@v3
      - name: Install dependencies
        run: npm [1]

Drag options to blanks, or click blank then click option'

Astart

Binstall

Cbuild

Dtest

Attempts:

3 left

💡 Hint

Common Mistakes

Using npm start runs the app instead of installing packages.

The npm install command installs all dependencies listed in package.json.

3fill in blank

hard

Fix the error in the step that runs tests by completing the command.

Node.js

      - name: Run tests
        run: npm [1]

Drag options to blanks, or click blank then click option'

Atest

Bbuild

Cinstall

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using npm build or npm start does not run tests.

The npm test command runs the test scripts defined in package.json.

4fill in blank

hard

Fill both blanks to create a job that runs on Ubuntu and caches npm dependencies.

Node.js

jobs:
  build:
    runs-on: [1]
    steps:
      - uses: actions/checkout@v3
      - name: Cache npm dependencies
        uses: actions/cache@v3
        with:
          path: ~/.npm
          key: ${{ runner.os }}-node-[2]

Drag options to blanks, or click blank then click option'

Aubuntu-latest

Bwindows-latest

C14

D18

Attempts:

3 left

💡 Hint

Common Mistakes

Using Windows runner when Linux is expected.

Using wrong Node.js version in cache key.

The job runs on Ubuntu latest version. The cache key includes Node.js version 18 to separate caches by version.

5fill in blank

hard

Fill all three blanks to define a workflow that triggers on pull requests, installs dependencies, and runs tests.

Node.js

name: CI
on: [1]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Install dependencies
        run: npm [2]
      - name: Run tests
        run: npm [3]

Drag options to blanks, or click blank then click option'

Apull_request

Binstall

Ctest

Dpush

Attempts:

3 left

💡 Hint

Common Mistakes

Using push instead of pull_request for trigger.

Mixing up install and test commands.

The workflow triggers on pull requests, installs dependencies with npm install, and runs tests with npm test.

Practice

1. What is the main purpose of a CI/CD pipeline in Node.js projects?

easy

A. To automate building, testing, and deploying code

B. To manually review code changes before deployment

C. To write code faster without testing

D. To store code backups only

Solution

1. Step 1: Understand CI/CD pipeline purpose

   A CI/CD pipeline automates repetitive tasks like building, testing, and deploying code to save time and reduce errors.

2. Step 2: Compare options against CI/CD definition

   To automate building, testing, and deploying code correctly states this automation purpose, while others describe manual or unrelated tasks.

3. Final Answer:

   To automate building, testing, and deploying code -> Option A

4. Quick Check:

   CI/CD pipeline purpose = automation [OK]

Hint: CI/CD means automate build, test, deploy [OK]

Common Mistakes:

• Thinking CI/CD is only for code backup
• Believing CI/CD replaces manual code review
• Assuming CI/CD skips testing

2. Which of the following is the correct syntax to define a simple GitHub Actions workflow file for Node.js that runs tests on push?

easy

A. name: Node.js CI
on: push
jobs:
build:
run-on: windows-latest
steps:
- uses: actions/checkout@v3
- uses: actions/setup-node@v3
with:
node-version: '18'
- run: npm install
- run: npm test

B. workflow: Node.js CI
trigger: push
steps:
- checkout
- setup-node 18
- run npm install
- run npm test

C. name: Node.js CI
on: push
jobs:
build:
runs-on: ubuntu-latest
steps:
- checkout
- setup-node
- run: npm install
- run: npm test

D. name: Node.js CI
on: push
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Use Node.js
uses: actions/setup-node@v3
with:
node-version: '18'
- run: npm install
- run: npm test

Solution

1. Step 1: Check GitHub Actions syntax

   The correct syntax uses 'name', 'on', 'jobs', 'runs-on', and 'steps' with proper indentation and action versions.

2. Step 2: Validate Node.js setup and OS

   name: Node.js CI on: push jobs: build: runs-on: ubuntu-latest steps: - uses: actions/checkout@v3 - name: Use Node.js uses: actions/setup-node@v3 with: node-version: '18' - run: npm install - run: npm test uses 'ubuntu-latest', correct action versions, and specifies node-version properly. name: Node.js CI on: push jobs: build: run-on: windows-latest steps: - uses: actions/checkout@v3 - uses: actions/setup-node@v3 with: node-version: '18' - run: npm install - run: npm test uses 'run-on: windows-latest' which is invalid key (should be 'runs-on'). Options B and C have syntax errors or missing versions.

3. Final Answer:

   Correct syntax and setup for Node.js CI workflow -> Option D

4. Quick Check:

   Correct GitHub Actions syntax = name: Node.js CI on: push jobs: build: runs-on: ubuntu-latest steps: - uses: actions/checkout@v3 - name: Use Node.js uses: actions/setup-node@v3 with: node-version: '18' - run: npm install - run: npm test [OK]

Hint: Look for correct YAML keys and action versions [OK]

Common Mistakes:

• Missing 'uses:' keyword before actions
• Incorrect indentation breaking YAML
• Not specifying node version properly

3. Given this GitHub Actions step in a Node.js CI pipeline:

      - run: npm test
        env:
          CI: true

What is the expected effect of setting CI=true in this context?

medium

A. It disables all tests to speed up the pipeline

B. It runs tests in continuous integration mode, causing failures on warnings

C. It installs dependencies before running tests

D. It deploys the app automatically after tests

Solution

1. Step 1: Understand CI environment variable

   Setting CI=true tells test runners to run in continuous integration mode, often making warnings cause test failures.

2. Step 2: Match effect to options

   It runs tests in continuous integration mode, causing failures on warnings correctly describes this behavior. Options A, C, and D describe unrelated or incorrect effects.

3. Final Answer:

   Runs tests in CI mode, causing failures on warnings -> Option B

4. Quick Check:

   CI=true means strict test mode [OK]

Hint: CI=true makes tests fail on warnings [OK]

Common Mistakes:

• Thinking CI=true skips tests
• Assuming CI=true installs dependencies
• Believing CI=true triggers deployment

4. You have this GitHub Actions workflow snippet for Node.js:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup Node
        uses: actions/setup-node@v3
        with:
          node-version: '16'
      - run: npm install
      - run: npm test
      - run: npm run deploy

The pipeline fails at the deploy step with "command not found" error. What is the likely cause?

medium

A. The deploy script is missing in package.json

B. Node.js version 16 does not support deploy commands

C. The checkout action is missing

D. npm install was not run before deploy

Solution

1. Step 1: Analyze error cause

   "command not found" during 'npm run deploy' usually means the deploy script is not defined in package.json.

2. Step 2: Check other steps

   Checkout and npm install steps exist, so code and dependencies are present. Node.js version 16 supports scripts. So missing deploy script is the cause.

3. Final Answer:

   The deploy script is missing in package.json -> Option A

4. Quick Check:

   Missing npm script causes command not found [OK]

Hint: Check package.json scripts for deploy command [OK]

Common Mistakes:

• Blaming Node.js version for script errors
• Ignoring missing npm scripts
• Assuming checkout or install steps are missing

5. You want to create a CI/CD pipeline for a Node.js app that builds, tests, and deploys only when code is pushed to the main branch. Which YAML snippet correctly restricts the pipeline to run only on pushes to main?

hard

A. on:
pull_request:
branches:
- main

B. on:
push:
tags:
- main

C. on:
push:
branches:
- main

D. on:
push:
branches-ignore:
- main

Solution

1. Step 1: Understand GitHub Actions triggers

   To run on pushes to main branch only, use 'on: push' with 'branches: [main]'.

2. Step 2: Analyze each trigger configuration

   on: push: branches: - main correctly uses branches filter. on: push: tags: - main filters tags, not branches. on: pull_request: branches: - main triggers on pull requests, not pushes. on: push: branches-ignore: - main ignores main branch pushes.

3. Final Answer:

   on push to main branch only -> Option C

4. Quick Check:

   Push to main branch = on.push.branches [OK]

Hint: Use 'on: push' with 'branches: main' to restrict runs [OK]

Common Mistakes:

• Confusing tags with branches
• Using pull_request instead of push
• Ignoring branches filter