How to easily fix the "Command not found" error in VS Code

Tari Ibaba
Last updated on November 13, 2023
How to easily fix the "Command not found" error in VS Code

Are you developing a Visual Studio Code extension and experiencing the "Command not found" error? Let's learn how to fix it in this article.

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1. Register command in package.json contributes

To fix the "Command not found" error in a VS Code extension, make sure your extension registers the command under the contributed field in your package.json file:

{
  ...
  "contributes": {
    "commands": [ ... ]
  }
  ...
}

2. Register command in package.json activationEvents

To fix the "Command not found" error in a VS Code extension, make sure you're added the command to the activationEvents array in your package.json file:

{
    ...
    "activationEvents": [
        "onCommand:extension.showMyExtension",
        "onCommand:extension.callMyExtension"
    ]
    ...
}

3. Check console logs for any errors

One common cause of "Command not found" error in a VS Code extension is an undetected JavaScript error. You may find such errors when you examine the VS Code console logs.

Head to the Help menu and select Toggle Developer Tools and inspect the console for potential errors.

4. Register command in extension.ts registerCommand()

To fix the "Command not found" error in a VS Code extension, make sure you're registered the command in extension.ts using vscode.commands.registerCommand():

// ...

export async function activate(context: vscode.ExtensionContext) {
  // ...
  
  // commandAction is a callback function
  context.subscriptions.push(
    vscode.commands.registerCommand('command_name', commandAction)
  );
  
  // ...
}

5. Compile TypeScript source manually

The "Command not found" error happens in a VS Code extension if the TypeScript source wasn't compiled to the out folder before launch or build.

This typically indicates a problem with your VS Code debug configuration, for example, preLaunchTask may be missing from launch.json:

launch.json should have a preLaunchTask which builds the VS Code extension's TypeScript files automatically.
launch.json should have a preLaunchTask which builds the TypeScript files automatically.

Or there may be a problem with the build script in package.json.

{
  ...
  "scripts": {
    ...
    "vscode:prepublish": "npm run esbuild-base -- --minify && npm run build",
    "esbuild-base": "rimraf out && esbuild ./ext-src/extension.ts --bundle --outfile=out/extension.js --external:vscode --format=cjs --platform=node",
    "build": "webpack && tsc -p tsconfig.extension.json",
    ...
  }
  ...
}

While you figure out what's preventing the automatic TypeScript compilation, you can do it yourself with the tsc command:

# NPM
npx tsc -p .

# Yarn
yarn tsc -p .

# PNPM
pnpm tsc -p .

6. Upgrade VS Code to match extension version

To fix the "Command not found" error in an extension, update VS Code to a version higher that what is specified in the engines.vscode field of your package.json file.

Or, downgrade engines.vscode to a version equal to or lower than the VS Code version you're using to run the extension.

{
  ...  
  "engines": {
    "vscode": "^1.80.0"
  },
  ...
}

Every Crazy Thing JavaScript Does

Every Crazy Thing JavaScript Does
Avoid painful bugs and save valuable time with Every Crazy Thing JavaScript Does, a captivating guide to the subtle caveats and lesser-known parts of JavaScript.

See also