Solve - mocha: command not found error

Solve - mocha: command not found error #

Use npx to solve the error "mocha: command not found", e.g. npx mocha or install the package globally by running npm install -g mocha to be able to use the command without the npx prefix.

The fastest way to solve the error is to use the npx command.

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npx mocha

npx mocha --version

If the error is not resolved, you can force the command to use the latest version of mocha.

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npx mocha@latest

npx mocha@latest --version

The commands above use the latest version of mocha.

Alternatively, you can install mocha globally or as a development dependency.

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# 👇️ installs mocha globally (can run from any directory)
npm install -g mocha

# 👇️ installs mocha locally to the project (must be ran from root directory)
npm install --save-dev mocha

The benefit of installing mocha as a development dependency is that you can control the version of the package in your package.json file.

You can also create a test command in the scripts object of your package.json file.

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{
  "scripts": {
      "test": "mocha"
  }
}

Now you would run the command as npm run test and not use mocha directly.

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# 👇️ if you get permissions error
sudo npm install -g mocha

mocha --version

You can link your project to the globally installed mocha package, by opening your terminal in your project's root directory (where your package.json file is) and running the npm link mocha command.

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npm link mocha

The npm link command creates a symbolic link from the globally installed package to the node_modules/ directory of the current folder.

If that doesn't help, run the following command:

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npm config get prefix

The command will show you the path where npm puts your globally installed packages. The global packages will be in the bin directory at the specified path.

Look at the PATH environment variable on your operating system and add the path that the npm config get prefix command outputs, if it's not already there.

If that didn't work, try to add the path to the bin folder (from npm config get prefix) to your PATH environment variable and restart your terminal.

For example, on macOS, you can update your path with the following command:

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# make sure path matches with npm config get prefix
export PATH=/usr/local/share/npm/bin:$PATH

And on Windows, the output of the npm config get prefix command will look something like: C:\Users\Your_User_Name\AppData\Roaming\npm.

Edit the environment variable on your machine and add the specified path (replacing the placeholder with your username).

If you are on linux, you can add the output from the npm config get prefix command to your .bashrc file.

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# 👇️ make sure to update the path with the output
# from the command
export PATH="/usr/local/share/npm/bin:$PATH"

If that doesn't help try to reinstall Node.js on your machine and then install mocha globally by running npm install -g mocha@latest.

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# 👇️ installs mocha globally (can run from any directory)
npm install -g mocha

# 👇️ installs mocha locally to the project (must be ran from root directory)
npm install --save-dev mocha

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# 👇️ if you get permissions error
sudo npm install -g mocha

mocha --version

Alternatively, you can see how you can fix the permissions error on this page in the official npm docs.