'use strict'; const common = require('../common'); const { describe, it, test } = require('node:test'); const assert = require('assert'); describe('Concurrency option (boolean) = true ', { concurrency: true }, () => { let isFirstTestOver = false; it('should start the first test', () => new Promise((resolve) => { setImmediate(() => { isFirstTestOver = true; resolve(); }); })); it('should start before the previous test ends', () => { // Should work even on single core CPUs assert.strictEqual(isFirstTestOver, false); }); }); describe( 'Concurrency option (boolean) = false ', { concurrency: false }, () => { let isFirstTestOver = false; it('should start the first test', () => new Promise((resolve) => { setImmediate(() => { isFirstTestOver = true; resolve(); }); })); it('should start after the previous test ends', () => { assert.strictEqual(isFirstTestOver, true); }); } ); { // Make sure tests run in order when root concurrency is 1 (default) const tree = []; const expectedTestTree = common.mustCall(() => { assert.deepStrictEqual(tree, [ 'suite 1', 'nested', 'suite 2', '1', '2', 'nested 1', 'nested 2', 'test', 'test 1', 'test 2', ]); }); describe('suite 1', () => { tree.push('suite 1'); it('1', () => tree.push('1')); it('2', () => tree.push('2')); describe('nested', () => { tree.push('nested'); it('nested 1', () => tree.push('nested 1')); it('nested 2', () => tree.push('nested 2')); }); }); test('test', async (t) => { tree.push('test'); await t.test('test1', () => tree.push('test 1')); await t.test('test 2', () => tree.push('test 2')); }); describe('suite 2', () => { tree.push('suite 2'); it('should run after other suites', expectedTestTree); }); }