Let each test file be executable on its own.

Usage no npm install needed!

<script type="module">
  import selfageTestRunner from 'https://cdn.skypack.dev/@selfage/test_runner';




npm install @selfage/test_runner


Written in TypeScript and compiled to ES6 with inline source map & source. See @selfage/tsconfig for full compiler options. Provides a simple test runner that makes each test file itself an exectuable file and is capable to be combined into one large test suite file.

Test runner for Node environment

Simple test

// math.ts
export function add(a: number, b: number): number {
  return a + b;

// math_test.ts
import { add } from './math';
import { NODE_TEST_RUNNER, Environment } from "@selfage/test_runner";

class ComplicatedEnv implements Environment {
  public setUp(): Promise<void> {
    // ...
  public tearDown(): Promise<void> {
    // ...

  // The name of this test set.
  name: "MathTest",
  // If you need to set up an environment for the entire test set, you can add
  // it like this.
  // environment: new ComplicatedEnv(),
  // Or define it inline.
  // environment: { setUp: () => {...}, tearDown: () => {...} },
  cases: [
      // The name of each test case.
      name: "UnderTen",
      // It can also be an async function.
      execute: () => {
        // Execute
        let res = add(1, 2);

        // Verify
        if (res !== 3) {
          throw new Error('Expect to be 3.');

After compiled with tsc, you can execute the test file via node math_test.js, which executes all test cases in this file and outputs success or failure of each case to console.

math_test.js is a executable file taking two command line arguments: --set-name or -s, and --case-name or -c. (node math_test.js -h brings up help menu.)

node math_test.js -c UnderTen would only execute the test case UnderTen.

node math_test.js -s MathTest would only execute the test set MathTest which is helpful in a test suite.

Test suite

Suppose we have 3 test files: math_test.ts, handler_test.ts, element_test.ts. The test_suite.ts contains the following.

import './math_test';
import './handler_test';
import './element_test';
// That's it!

After compiled with tsc, you can execute it via node test_suite.js, which executes all test sets in all test files and outputs success or failure of each case to console. It's helpful to include all tests in a project that needs to pass before, e.g., commiting or releasing.

test_suite.js is a executable file that takes -s and -c, just like math_test.js.

node test_suite.js -s MathTest makes more sense in that it only executes the test set MathTest.

node test_suite.js -s MathTest -c UnderTen would only execute the test case UnderTen from the test set MathTest.

Test runner for Puppeteer executor environment

Puppeteer executor environment

See @selfage/bundler_cli#puppeteer-executor-environment. TLDR, it's a headless Chrome environment but with some additional API provided by @selfage/bundler_cli.

Add and run tests

API-wise, the only difference from above is import PUPPETEER_TEST_RUNNER.

import { PUPPETEER_TEST_RUNNER } from "@selfage/test_runner";

  // ...

Then run the test file with @selfage/bundler_cli, e.g. $ bundage prun math_test -- -c UnderTen. It will close the browser/page automatically, upon all tests finished. See @selfage/bundler_cli#run-in-puppeteer for CLI explanation. And see @selfage/puppeteer_executor_api for how to control browser behavior for testing purpose, such as screenshot and set viewport.

Stack trace from TypeScript source file

Based on the amazing source-map-support package, stack traces from errors, especially when assertion failed, will be mapped back to TypeScript source files.