JS/TS APIs

On startup TrailBase will automatically load any JavaScript and TypeScript files in traildepot/scripts. This can be used to implement arbitrary HTTP APIs using custom handlers.

Example HTTP Endpoint

The following example illustrates a few things:

How to register a parameterized route with {table}.
How to implement a handler that returns text/plain content. There is also jsonHandler and htmlHandler.
How to query the database.
How to return an error.

import {
  addRoute,
  query,
  stringHandler,
  HttpError,
  StatusCodes
} from "../trailbase.js";

addRoute("GET", "/test/{table}", stringHandler(async (req) => {
  const table = req.params["table"];
  if (table) {
    const rows = await query(`SELECT COUNT(*) FROM ${table}`, [])
    return `entries: ${rows[0][0]}`;
  }

  throw new HttpError(
      StatusCodes.BAD_REQUEST, "Missing '?table=' search query param");
}));

More examples can be found in the repository in client/testfixture/scripts/index.ts.

Runtime Details

At its heart, TrailBase’s runtime is a pool of V8 worker threads - called isolates - alongside a runtime that supports basic tasks such as file I/O, web requests, timers, etc. While it uses Deno’s V8-integration under the hood, it is not a full Node.js runtime, at least for now.