Code completion and IntelliSense

IntelliSense in Visual Studio Code can significantly enhance your scripting experience with Browsertime and by providing code completions, parameter info, quick info, and member lists. Here's how to set it up.


Before starting, ensure that you have NodeJS and npm installed on your system. You can download them from NodeJS official website.

Step 1: Create a New Project

  1. Create a new directory for your project.
  2. Open a terminal and navigate to your project directory.
  3. Run the following command to initialize a new npm project: npm init
  4. Follow the prompts to set up your project.

Step 2: Install Browsertime

To install Browsertime and its types, use npm. In your project directory, run:

npm install browsertime --save-dev

This command installs Browsertime as a developer dependency.

Step 3: Configure Visual Studio Code

  1. In Visual Studio Code, open your project.
  2. Go to Settings (use Ctrl + , or Cmd + , on Mac).
  3. Search for JavaScript › Suggest: Names.
  4. Disable this setting. This helps in ensuring that IntelliSense only suggests existing properties and functions related to Browsertime objects.

Step 4: Reload Visual Studio Code

After making these changes, reload Visual Studio Code to apply the new settings.

Step 5: Start Scripting

Now, as you write your Browsertime scripts, IntelliSense will assist you as long as you add the correct parameters. It automatically suggests relevant methods and properties. Here's a template to get you started:

 * @param {import('browsertime').BrowsertimeContext} context
 * @param {import('browsertime').BrowsertimeCommands} commands
export default async function (context, commands) { 


Bonus Tip: Create Custom Snippets

You can further streamline your workflow by creating custom snippets in Visual Studio Code. Learn how to create them at User Defined Snippets in Visual Studio Code.

Here's an example on how to create a snippet for basic script:

  1. Open VS Code Command Palette: Press Ctrl + Shift + P (or Cmd + Shift + P on Mac) to open the Command Palette.
  2. Open Snippets File: Type Configure User Snippets and select it. Then, choose New Global Snippets file or select an existing language-specific snippets file if you prefer the snippet to be language-specific.
  3. Define Your Snippet: In the opened JSON file, define your snippet as follows:
  " script template": {
    "prefix": "sitespeed.ioScripting",
    "body": [
      " *",
      " * @param {import('browsertime').BrowsertimeContext} context",
      " * @param {import('browsertime').BrowsertimeCommands} commands",
      " */",
      "export default async function (context, commands) {",
      "    // Your code here",
    "description": " scripting"

Replace "sitespeed.ioScripting" with your preferred prefix that will trigger the snippet.

  1. Save the Snippets File: Save the file (Ctrl + S or Cmd + S).