TST: TypeScript Tester

Simple testing tool to run and test TypeScript code in combination with assertion libraries.

Command Line Arguments

  • [options] : Optional flags explained in the section below.

  • [source] : Source folder with TypeScript tests.

Command Line Options

  • –help, -h : Prints this help text.

  • –only [path] : Runs a single test in [source].

  • –reset : Compiles into an empty TypeScript target.

  • –verbose : Prints test details.

  • –version, -v : Prints the version string.


Install the testing tool.

$ npm install @typescriptlibs/tst

Import the default test function in the following pattern. If you like to use a custom assert library, you can ignore the assert argument.

import test from '@typescriptlibs/tst';

test('Test the answer to the ultimate question.', (assert: test.Assert) => {
        'The answer to the ultimate question should be the cube root of 74088.'

test('Test the timeout function.', async (assert: test.Assert) => {
    const time = Date.now();

    await new Promise((resolve) => setTimeout(resolve, 100));

    const delta = Date.now() - time;

        delta > 100,
        `The timeout should fire after 100 milliseconds. (${delta})`

Compile, load and run assertion tests in the “tests” folder.

$ npx tst tests/