Test a module

Run shared code as TypeScript

Vitest

vitest.config.ts

import { createRequire } from "node:module";
import { defineConfig } from "vitest/config";

const require = createRequire(import.meta.url);

export default defineConfig({
  resolve: { alias: { "lucent:core": require.resolve("@lucent-lang/lucent/core") } },
});

Jest

jest.config.js

module.exports = {
  moduleNameMapper: { "^lucent:core$": "@lucent-lang/lucent/core" },
};

trip.test.ts

import { expect, it } from "vitest";
import { Trip } from "./src/trip.lucent";

it("rejects a fix that arrives late", () => {
  const trip = new Trip();
  trip.add({ latitude: 48.85, longitude: 2.29, time: 1000 });
  expect(() => trip.add({ latitude: 48.86, longitude: 2.3, time: 0 })).toThrow(
    expect.objectContaining({ code: "E_OUT_OF_ORDER" }),
  );
});

A module is TypeScript, so your test runner can run it as is. @lucent-lang/lucent/core is the JavaScript version of lucent:core, for delay, error and the rest. Modules with platform code can't run this way: their SDK calls need the app.

Compare native and JavaScript

terminal

npx lucent bench

lucent bench runs each case of your *.bench.ts files as the compiled module and as JavaScript, and fails when the results differ. It needs a desktop Hermes, at ~/hermes or in HERMES_DIR.

Test platform code's neighbors

terminal

npx lucent build --platforms host --out .lucent/host

A host build compiles for your computer. Platform code there throws this code runs only on iOS and Android, so the shared code around it can run in tests.

Run on devices

SDK calls run only in the app. Build it for the simulator and the emulator, and check each platform's branch there.