npm run watch

Compiling your TypeScript code

Since TypeScript sources need to be compiled to JavaScript, every time we make a modification to our source files, we would want them to be compiled to .js.

This is an important step. Make sure you leave the “watch” terminal session open at the end of this step.

Your project is already configured with a nice little npm script called watch.

Open new terminal window

Open a new terminal session (or tab). You will keep this window open in the background for the duration of the workshop.

Start watching for changes

From your project directory run:

cd cdk-workshop


npm run watch

Then, screen will be cleared and you’ll see:

Starting compilation in watch mode...
Found 0 errors. Watching for file changes.

This will start the TypeScript compiler (tsc) in “watch” mode, which will monitor your project directory and will automatically compile any changes to your .ts files to .js.

‼️ Keep this terminal window open with watch running for the duration of the workshop.