A no-bullshit-stupid-simple-test-runner for node

stupid-test-runner.js

/*
// USAGE:

const { describe, it, run, assert } = require('./stupid-test-runner.js'); 

describe('Philosophers and Their Unlikely Assertions', () => {
  
  describe('Socrates', () => {
    it('should know that he knows nothing', async () => {
      const url = 'https://socratic.com/paradox/knowledge';
      const result = await fetch(url).then(x => x.text());
          
      assert(!result, 'Socrates claims to know something!');
    });
  });
  
  describe('Descartes', () => {
    it('should think, therefore he is', () => {
      const thinking = true;
      assert(thinking === true, 'Descartes is not thinking?');
    });
  });
});

run();
*/

const A_DOUBLE_LINE = '========================================';
const A_SINGLE_LINE = '----------------------------------------';

const root = {
  name: 'root',
  tests: [],
  children: [],
};

const stack = [root];

function create(name) {
  return {
    name,
    tests: [],
    children: [],
    failures: 0,
  };
}

function push(context) {
  stack[stack.length - 1].children.push(context);
  stack.push(context);
}

function pop() {
  stack.pop();
}

function currentContext() {
  return stack[stack.length - 1];
}

async function runContext(context) {
  let failures = 0;

  console.log(A_DOUBLE_LINE);
  console.log(`${context.name}`);

  for (const test of context.tests) {
    console.log(A_SINGLE_LINE);
    console.log(`${test.name}`);
    try {
      await test.fn();
    } catch (error) {
      console.error(error);
      failures++;
    }
  }

  for (const child of context.children) {
    failures += await runContext(child);
  }

  context.failures = failures;

  return failures;
}

async function describe(name, fn) {
  const context = create(name);
  push(context);
  await fn();
  pop();
}

async function it(name, fn) {
  const context = currentContext();
  context.tests.push({ name, fn });
}

async function run() {
  let current = root;
  await runContext(current);

  console.log();
  console.log(A_SINGLE_LINE);
  console.log(`Failures: ${current.failures}`);
  console.log(A_SINGLE_LINE);
}

function assert(test, msg = 'Assertion failed') {
  if (!test) {
    throw new Error(msg);
  }
}

module.exports = {
  describe,
  it,
  run,
  assert,
};