How to use the command npm-check (with examples)

The npm-check command is a useful tool for checking and managing npm package dependencies. It allows developers to easily identify outdated, incorrect, and unused dependencies in their project and provides options for updating packages interactively or automatically. The command can be run from the command line and provides detailed reports on the status of the dependencies.

Use case 1: Display a report of outdated, incorrect, and unused dependencies

Code:

npm-check

Motivation: By running the npm-check command without any additional arguments, you can quickly generate a report that displays information about all the outdated, incorrect, and unused dependencies in your project. This report can help you identify potential vulnerabilities or performance issues associated with the outdated dependencies or dependencies that are no longer needed.

Explanation: The npm-check command is used without any arguments to initiate the check for outdated, incorrect, and unused dependencies. It scans the project’s package.json file and compares the listed dependencies with the latest versions available in the npm registry.

Example output:

# npm-check Report
Outdated dependencies:
Package               Current  Wanted  Latest  Location
--------------------- -------- ------- ------- --------
react                 16.8.0   16.8.0  17.0.2  package.json
react-dom             16.8.0   16.8.0  17.0.2  package.json

Incorrect versions:
Package               Current  Expected  Location
--------------------- -------- --------- ---------
express               4.17.1   >=4.16.1  package.json

Unused dependencies:
Package               Location
--------------------- -----------
redux                 package.json

In this example, the report identifies two outdated dependencies (react and react-dom), one incorrect version (express), and one unused dependency (redux).

Use case 2: Interactively update out-of-date packages

Code:

npm-check --update

Motivation: When you want to update specific out-of-date packages manually, you can use the --update option with the npm-check command. This will present you with an interactive menu where you can select the packages that you want to update.

Explanation: By using the --update option, the npm-check command allows you to interactively update out-of-date packages. When this option is specified, a menu is displayed listing all the out-of-date packages detected during the check. You can select individual packages or choose to update all the packages at once.

Example output:

Interactive update:

? Choose which packages to update (Press <space> to select, <a> to toggle all, <i> to invert selection)
❯◯ react (16.8.0) → 17.0.2
 ◯ react-dom (16.8.0) → 17.0.2

In this example, the command prompts you to select the packages that you want to update interactively. You can use the spacebar to toggle the selection, and then press Enter to proceed with the update.

Use case 3: Update everything without prompting

Code:

npm-check --update-all

Motivation: When you want to update all the out-of-date packages without manually selecting them, you can use the --update-all option with the npm-check command. This allows you to update all the packages in one go, without having to go through the interactive menu.

Explanation: The --update-all option, when used with the npm-check command, updates all the out-of-date packages without displaying an interactive menu. It automatically updates all packages to their latest versions.

Example output:

All packages were successfully updated.

Outdated Packages:
Package               Updated To
--------------------- ----------
react                 17.0.2
react-dom             17.0.2

In this example, the command automatically updates all the out-of-date packages to their latest versions without requiring any manual intervention.

Use case 4: Don’t check for unused packages

Code:

npm-check --skip-unused

Motivation: In some cases, you may not be interested in checking for unused packages, as they may not pose any significant issues to your project. By using the --skip-unused option with the npm-check command, you can exclude the check for unused packages, making the process faster.

Explanation: The --skip-unused option, when used with the npm-check command, skips the check for unused packages. It only focuses on identifying and reporting outdated and incorrect dependencies.

Example output:

# npm-check Report
Outdated dependencies:
Package               Current  Wanted  Latest  Location
--------------------- -------- ------- ------- --------
react                 16.8.0   16.8.0  17.0.2  package.json
react-dom             16.8.0   16.8.0  17.0.2  package.json

Incorrect versions:
Package               Current  Expected  Location
--------------------- -------- --------- ---------
express               4.17.1   >=4.16.1  package.json

In this example, the report excludes the section for unused dependencies and only includes information about outdated and incorrect dependencies. This can be useful when you want to focus solely on updating outdated and incorrect dependencies.