Run code

skuba lets you interactively run your TypeScript source code during development. The following commands are powered by ts-node and ts-node-dev.

These commands are only intended to serve local development and simple scripting scenarios, as a TypeScript process can present substantial overhead at runtime. In production, we recommend skuba building your project and executing under a regular Node.js runtime.

skuba node

Runs a TypeScript source file:

skuba node src/some-cli-script.ts

# ...

or launches a ts-node REPL if a file is not provided:

skuba node src/some-cli-script.ts

>

skuba node automatically registers your tsconfig.json paths as module aliases for ease of local development. If you use these aliases in your production code, your entry point(s) will need to import a runtime module alias resolver like skuba-dive/register or tsconfig-paths. For example, your src/app.ts may look like:

// This must be imported directly within the `src` directory.
import 'skuba-dive/register';

// You can use the `src` module alias after registration.
import { rootLogger } 'src/framework/logging';

skuba start

Starts a live-reloading server for local development.

skuba start src/app.ts

The entry point is chosen from:

  1. Command line argument: skuba start src/app.ts
  2. Manifest configuration: package.json#/skuba/entryPoint
  3. Default: src/app.ts

skuba start automatically registers your tsconfig.json paths as module aliases for ease of local development. If you use these aliases in your production code, your entry point(s) will need to import a runtime module alias resolver like skuba-dive/register or tsconfig-paths. For example, your src/app.ts may look like:

// This must be imported directly within the `src` directory.
import 'skuba-dive/register';

// You can use the `src` module alias after registration.
import { rootLogger } 'src/framework/logging';

Start an executable script

Your entry point can be a simple module that runs on load:

console.log('Hello world!');

Start a Lambda function handler

Your entry point can target an exported function:

skuba start --port 12345 src/app.ts#handler

export const handler = async (event: unknown, ctx: unknown) => {
  // ...

  return;
};

This starts up a local HTTP server that you can POST arguments to:

curl --data '["event", {"awsRequestId": "123"}]' --include localhost:12345

Start an HTTP server

Your entry point should export:

interface Export {
  // One of these is required.
  callback?: () => http.RequestListener;
  requestListener?: http.RequestListener;
  server?: http.Server;

  // Optional; falls back to an available port.
  port?: number;
}

Koa should work with minimal fuss:

const app = new Koa();

// You can also use `export =` syntax as required by koa-cluster.
export default Object.assign(app, { port });

As should Fastify:

const createApp = async () => {
  const app = fastify();
  await app.ready();
  return app;
};
const app = createApp();

export default app;

As should Express:

const app = express();

export default Object.assign(app, { port });

As should a HTTP Server:

const app = http.createServer();

export default Object.assign(app, { port });

Debugging options

The --inspect and --inspect-brk Node.js options are supported for debugging sessions.

Automatically attaching a debugger

The simplest way to attach a debugger to VS Code is to use its built-in debug terminal.

  1. Hit ⌘ + ⇧ + P to bring up the Command Palette.
  2. Select Debug: JavaScript Debug Terminal
  3. Run any command within the terminal; for example, skuba test, skuba start and VS Code will automatically attach to it.

Manually attaching a debugger

Try this out by starting your project with inspector enabled:

pnpm start:debug

Next, attach VS Code’s debugger to the running process:

  1. Hit ⌘ + ⇧ + P to bring up the Command Palette.
  2. Select Debug: Attach to Node Process
  3. Select the node process that is pointing to pnpm start:debug
Pick the node.js process to attach to

...

node /Users/seeker/.nvm/versions/node/vX.Y.Z/bin/pnpm start --inspect-brk
process id: 1000 (SIGUSR1)

If all goes well, the Status Bar will turn orange. We can progress past the initial breakpoint by pressing the ▶️ button, then test out a custom breakpoint.

For example, you could set one in your health check handler if you’re working on an API:

// src/api/healthCheck.ts

🔴 6  ctx.body = '';

Then try cURLing your health check endpoint:

curl --include localhost:<port>/health

Execution should pause on the breakpoint until we hit F5 or the ▶️ button.