NestJS CLI installation - Step-by-Step Execution

Concept Flow - NestJS CLI installation

Open Terminal

↓

Check Node.js Installed?

No→Install Node.js

Yes↓

Run npm install -g @nestjs/cli

↓

Verify CLI Installation with nest --version

↓

Ready to create NestJS projects

This flow shows the steps to install NestJS CLI: open terminal, ensure Node.js is installed, install CLI globally, verify installation, then start using it.

Execution Sample

NestJS

npm install -g @nestjs/cli
nest --version

Installs NestJS CLI globally and checks the installed version.

Execution Table

Step	Action	Command Run	Result	Next Step
1	Open terminal	N/A	Terminal ready	Check Node.js installed
2	Check Node.js	node -v	v18.15.0	Run npm install -g @nestjs/cli
3	Install NestJS CLI globally	npm install -g @nestjs/cli	CLI installed successfully	Verify CLI installation
4	Verify CLI installation	nest --version	9.0.0	Ready to create projects
5	End	N/A	NestJS CLI ready to use	N/A

💡 NestJS CLI installed and verified, ready for project creation.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
Node.js Version	Not checked	v18.15.0	v18.15.0	v18.15.0	v18.15.0
NestJS CLI Installed	No	No	Yes	Yes	Yes
NestJS CLI Version	N/A	N/A	N/A	9.0.0	9.0.0

Key Moments - 3 Insights

What if 'node -v' command fails at step 2?

If 'node -v' fails, Node.js is not installed or not in PATH. You must install Node.js first before installing NestJS CLI. See step 2 in execution_table.

Why do we use '-g' in 'npm install -g @nestjs/cli'?

The '-g' flag installs the CLI globally so you can run 'nest' command anywhere in the terminal. This is shown in step 3 of execution_table.

What does 'nest --version' confirm?

'nest --version' confirms the CLI installed correctly and shows its version. This verification is step 4 in execution_table.

Visual Quiz - 3 Questions

Look at the execution table, what is the Node.js version after step 2?

A v18.15.0

B v16.0.0

C Not installed

D v20.0.0

💡 Hint

Check the 'Result' column in row for step 2 in execution_table.

At which step does the NestJS CLI become installed?

A Step 2

B Step 4

C Step 3

D Step 1

💡 Hint

Look at the 'NestJS CLI Installed' variable in variable_tracker after each step.

If 'nest --version' shows an error, what should you check first?

A If Node.js is installed

B If NestJS CLI was installed globally

C If terminal is open

D If npm is updated

💡 Hint

Refer to key_moments about the '-g' flag and step 4 verification.

Concept Snapshot

NestJS CLI Installation:
1. Open terminal
2. Ensure Node.js installed (node -v)
3. Run npm install -g @nestjs/cli to install CLI globally
4. Verify with nest --version
5. CLI ready to create projects

Full Transcript

To install the NestJS CLI, first open your terminal. Check if Node.js is installed by running 'node -v'. If Node.js is not installed, install it first. Then run 'npm install -g @nestjs/cli' to install the CLI globally. After installation, verify it by running 'nest --version' which should show the CLI version. Once verified, you can start creating NestJS projects using the CLI commands.

Practice

1. What is the main purpose of the NestJS CLI?

easy

A. To help create and manage NestJS projects easily

B. To run NestJS applications in production

C. To replace Node.js runtime

D. To write CSS styles for NestJS apps

Solution

1. Step 1: Understand what CLI tools do

   CLI tools help automate tasks like creating and managing projects.

2. Step 2: Match NestJS CLI purpose

   NestJS CLI specifically helps start and manage NestJS projects quickly.

3. Final Answer:

   To help create and manage NestJS projects easily -> Option A

4. Quick Check:

   NestJS CLI = project management tool [OK]

Hint: CLI means command line helper for projects [OK]

Common Mistakes:

• Thinking CLI runs the app in production
• Confusing CLI with runtime environment
• Assuming CLI styles the app

2. Which command correctly installs the NestJS CLI globally using npm?

easy

A. npm install nestjs-cli

B. npm install -g @nestjs/cli

C. npm global add nestjs

D. npm install @nestjs/cli

Solution

1. Step 1: Identify npm global install syntax

   Global install uses npm install -g package-name.

2. Step 2: Match correct package name

   The official NestJS CLI package is @nestjs/cli.

3. Final Answer:

   npm install -g @nestjs/cli -> Option B

4. Quick Check:

   Global install = npm install -g @nestjs/cli [OK]

Hint: Global npm installs use -g flag [OK]

Common Mistakes:

• Omitting the -g flag for global install
• Using wrong package name
• Using npm global add instead of install -g

3. After installing NestJS CLI globally, what happens when you run nest new my-app?

medium

A. It deletes the 'my-app' folder if it exists

B. It runs the NestJS server immediately

C. It creates a new NestJS project folder named 'my-app'

D. It updates the NestJS CLI to the latest version

Solution

1. Step 1: Understand the nest new command

   This command creates a new project folder with starter files.

2. Step 2: Analyze the argument 'my-app'

   The argument specifies the folder name for the new project.

3. Final Answer:

   It creates a new NestJS project folder named 'my-app' -> Option C

4. Quick Check:

   nest new = create project folder [OK]

Hint: nest new always creates a new project folder [OK]

Common Mistakes:

• Thinking it runs the server immediately
• Assuming it updates CLI version
• Believing it deletes folders

4. You run npm install -g nestjs/cli but get an error. What is the likely problem?

medium

A. You must use yarn instead of npm

B. You forgot to add the -g flag for global install

C. You need to run the command inside a NestJS project folder

D. The package name is incorrect; it should be '@nestjs/cli'

Solution

1. Step 1: Check the package name format

   Correct package name uses the scope '@nestjs/cli', not 'nestjs/cli'.

2. Step 2: Understand npm package naming

   Scoped packages start with '@' and are required for correct install.

3. Final Answer:

   The package name is incorrect; it should be '@nestjs/cli' -> Option D

4. Quick Check:

   Correct package name = @nestjs/cli [OK]

Hint: Scoped packages start with @ symbol [OK]

Common Mistakes:

• Using slash instead of @ for scoped package
• Forgetting -g flag (but question says it is present)
• Thinking install must be inside project folder

5. You want to install NestJS CLI globally but only for your current user without admin rights. Which command should you use?

hard

A. npm install -g @nestjs/cli --prefix ~/.npm-global

B. npm install @nestjs/cli

C. npm install -g @nestjs/cli

D. npm install --save @nestjs/cli

Solution

1. Step 1: Understand global install without admin rights

   Global install usually needs admin rights; using --prefix installs globally in user folder.

2. Step 2: Match command with user-level global install

   Using npm install -g @nestjs/cli --prefix ~/.npm-global installs CLI globally for current user only.

3. Final Answer:

   npm install -g @nestjs/cli --prefix ~/.npm-global -> Option A

4. Quick Check:

   User-level global install = npm install -g with --prefix [OK]

Hint: Use --prefix to install global packages without admin rights [OK]

Common Mistakes:

• Using normal install without -g for global tools
• Trying to install globally without admin rights and no prefix
• Confusing --save with global install