Cypress installation (npm install cypress) - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What does the command npm install cypress do?

When you run npm install cypress in your project folder, what happens?

A It downloads and installs the Cypress testing tool and adds it to your project's dependencies.

B It runs all Cypress tests in your project automatically.

C It updates the Node.js version on your computer to support Cypress.

D It creates a new Cypress project with default test files.

💡 Hint

Think about what npm install generally does for packages.

The command npm install cypress downloads the Cypress package from the npm registry and installs it into your project's node_modules folder. It also adds Cypress as a dependency in your package.json file.

❓ Predict Output

intermediate

What is the output after running npm install cypress successfully?

After running npm install cypress in a new project, what message will you see indicating success?

A Error: Cannot find module 'cypress'

B added 257 packages, and audited 258 packages in 12s

C Cypress tests executed successfully

D npm: command not found

💡 Hint

Look for a message that confirms package installation, not test execution.

When npm install completes successfully, it shows a message like added 257 packages, and audited 258 packages in 12s. It does not run tests or show errors.

❓ locator

advanced

Where does Cypress get installed after running npm install cypress?

After installing Cypress with npm, where can you find the Cypress executable files in your project?

A Inside the <code>node_modules/cypress</code> folder within your project directory.

B In the root folder of your project, as a standalone <code>cypress</code> folder.

C In the global npm folder outside your project directory.

D Inside the <code>tests/cypress</code> folder created automatically.

💡 Hint

Think about where npm installs packages locally by default.

npm installs packages inside the node_modules folder in your project. Cypress files will be under node_modules/cypress.

❓ assertion

advanced

Which assertion correctly verifies Cypress is installed in a Node.js project?

Given the following Node.js code snippet, which assertion correctly checks that Cypress is listed as a dependency in package.json?

Cypress

const fs = require('fs');
const packageJson = JSON.parse(fs.readFileSync('package.json', 'utf-8'));
// Which assertion below is correct?

A assert(packageJson.scripts.cypress === 'install')

B assert(packageJson.devDependencies.includes('cypress'))

C assert(packageJson.dependencies.cypress === undefined)

D assert(packageJson.dependencies.hasOwnProperty('cypress'))

💡 Hint

Check how dependencies are stored in package.json as objects, not arrays.

Dependencies in package.json are objects with package names as keys. Using hasOwnProperty('cypress') checks if Cypress is listed.

🔧 Debug

expert

Why does npm install cypress fail with ERR! code E404?

You run npm install cypress but get this error: npm ERR! 404 Not Found - GET https://registry.npmjs.org/cypress - Not found. What is the most likely cause?

A Your internet connection is down or npm registry is unreachable.

B You need to run <code>npm init</code> before installing any package.

C You typed the package name incorrectly or it does not exist in npm registry.

D Your Node.js version is too old to support Cypress installation.

💡 Hint

Check the error message carefully for clues about the package name or registry.

An ERR! 404 Not Found means npm cannot find the package in its registry. This usually happens if the package name is misspelled or does not exist.

Practice

1. What is the correct command to install Cypress as a development dependency using npm?

easy

A. npm install cypress --global

B. npm install cypress --save-dev

C. npm install cypress --save

D. npm install cypress --production

Solution

1. Step 1: Understand npm install flags

   The --save-dev flag installs the package as a development dependency, which is correct for Cypress.

2. Step 2: Compare options

   Options A, C, and D use incorrect flags for Cypress installation as a dev dependency.

3. Final Answer:

   npm install cypress --save-dev -> Option B

4. Quick Check:

   Install Cypress as dev dependency = npm install cypress --save-dev [OK]

Hint: Use --save-dev to install testing tools like Cypress [OK]

Common Mistakes:

• Using --global installs globally, not per project
• Using --save installs as production dependency
• Omitting --save-dev installs but not saved in devDependencies

2. Which folder should you be in before running npm install cypress --save-dev?

easy

A. The folder containing your package.json

B. The global npm modules folder

C. Any folder on your computer

D. The Cypress installation folder

Solution

1. Step 1: Identify project root folder

   npm installs packages into the current project, so you must be in the folder with package.json.

2. Step 2: Eliminate other options

   Installing anywhere else won't link Cypress to your project correctly.

3. Final Answer:

   The folder containing your package.json -> Option A

4. Quick Check:

   Install inside project folder with package.json [OK]

Hint: Always run npm install where package.json lives [OK]

Common Mistakes:

• Running npm install in random folders
• Trying to install inside global npm folder
• Assuming Cypress folder exists before install

3. After running npm install cypress --save-dev, what command do you use to open the Cypress Test Runner?

medium

A. npx cypress open

B. cypress start

C. npm run cypress

D. npm start cypress

Solution

1. Step 1: Recall Cypress start command

   The correct command to open Cypress Test Runner is npx cypress open.

2. Step 2: Check other options

   Options A, B, and C are not valid commands to open Cypress.

3. Final Answer:

   npx cypress open -> Option A

4. Quick Check:

   Open Cypress with npx cypress open [OK]

Hint: Use npx to run Cypress without global install [OK]

Common Mistakes:

• Trying npm start or npm run without scripts
• Typing cypress start instead of npx cypress open
• Not using npx after local install

4. You ran npm install cypress --save-dev but get an error saying command not found: cypress when typing cypress open. What is the likely fix?

medium

A. Restart your computer

B. Reinstall Cypress globally with npm install -g cypress

C. Delete node_modules and reinstall

D. Run npx cypress open instead

Solution

1. Step 1: Understand local vs global commands

   Cypress installed locally is not available as a global command, so cypress open fails.

2. Step 2: Use npx to run local binaries

   Using npx cypress open runs the local Cypress binary correctly.

3. Final Answer:

   Run npx cypress open instead -> Option D

4. Quick Check:

   Use npx for local binaries to avoid command not found [OK]

Hint: Use npx to run local packages without global install [OK]

Common Mistakes:

• Trying to run cypress without npx after local install
• Installing Cypress globally unnecessarily
• Ignoring error and assuming install failed

5. You want to add Cypress to your project and ensure it is only used during development. Which sequence of commands correctly installs Cypress and opens the test runner?

hard

A. npm install cypress --global && npx cypress open

B. npm install cypress && cypress open

C. npm install cypress --save-dev && npx cypress open

D. npm install cypress --save && npm start cypress

Solution

1. Step 1: Install Cypress as a development dependency

   Use npm install cypress --save-dev to add Cypress only for development.

2. Step 2: Open Cypress Test Runner correctly

   Use npx cypress open to run Cypress without global install.

3. Final Answer:

   npm install cypress --save-dev && npx cypress open -> Option C

4. Quick Check:

   Dev install + npx open = correct Cypress setup [OK]

Hint: Install with --save-dev then open with npx cypress open [OK]

Common Mistakes:

• Installing Cypress globally when not needed
• Running cypress open without npx after local install
• Using npm start without proper scripts