AsyncLoad.test.ts

import { describe, test, expect } from '@jest/globals';
import { asyncLoad, resolvePath } from '#js/util/AsyncLoad.js';
import { mathjax } from '#js/mathjax.js';

describe('asyncLoad()', () => {
  test('asyncLoad()', async () => {
    //
    // Throws error if not set in mathjax
    //
    expect(
      asyncLoad('x.js')
        .then(() => false)
        .catch(() => true)
    ).resolves.toBe(true);

    //
    // mathjax.asyncLoad returns value
    //
    mathjax.asyncLoad = (_name: string) => 'success';
    await expect(asyncLoad('x.js')).resolves.toBe('success');

    //
    // mathjax.asyncLoad throws error
    //
    mathjax.asyncLoad = (_name: string) => {
      throw 'fail';
    };
    await expect(asyncLoad('x.js')).rejects.toBe('fail');

    //
    // mathjax.asyncLoad returns promise
    //
    mathjax.asyncLoad = (_name: string) =>
      Promise.resolve().then(() => 'success');
    await expect(asyncLoad('x.js')).resolves.toBe('success');

    //
    // mathjax.asyncLoad returns promise that rejects
    //
    mathjax.asyncLoad = (_name: string) =>
      Promise.reject().catch(() => {
        throw 'fail';
      });
    await expect(asyncLoad('x.js')).rejects.toBe('fail');
  });

  test('resolvePath', () => {
    //
    // Test resolvePath woth Pacakge path resolution
    //
    (global as any).MathJax = {
      _: {
        components: {
          package: {
            Package: {
              resolvePath: (file: string) => 'test:' + file,
            },
          },
        },
      },
    };
    expect(resolvePath('[x]/y.js', (file) => file)).toBe('test:[x]/y.js');

    //
    // Remove MathJax._ and test relative and absolute paths
    //
    (global as any).MathJax = {};
    expect(
      resolvePath(
        './x.js',
        (file) => `rel:${file.substring(2)}`,
        (file) => `abs:${file}`
      )
    ).toBe('rel:x.js');
    expect(
      resolvePath(
        'x.js',
        (file) => `rel:${file.substring(2)}`,
        (file) => `abs:${file}`
      )
    ).toBe('abs:x.js');
  });
});