headers_test.js

import assert from 'assert';
import acceptedLanguages from '../src/accepted_languages';

suite('parse headers', () => {
  test('without quality values', () => {
    assert.deepStrictEqual(
      acceptedLanguages('en-US, fr, pl'), [
        'en-US',
        'fr',
        'pl'
      ]
    );
    assert.deepStrictEqual(
      acceptedLanguages('sr-Latn'), [
        'sr-Latn'
      ]
    );
  });

  test('with quality values', () => {
    assert.deepStrictEqual(
      acceptedLanguages('fr-CH, fr;q=0.9, en;q=0.8, de;q=0.7, *;q=0.5'), [
        'fr-CH',
        'fr',
        'en',
        'de',
        '*'
      ]
    );
  });

  test('with out of order quality values', () => {
    assert.deepStrictEqual(
      acceptedLanguages('en;q=0.8, fr;q=0.9, de;q=0.7, *;q=0.5, fr-CH'), [
        'fr-CH',
        'fr',
        'en',
        'de',
        '*'
      ]
    );
  });

  test('with equal q values', () => {
    assert.deepStrictEqual(
      acceptedLanguages('en;q=0.1, fr;q=0.1, de;q=0.1, *;q=0.1'), [
        'en',
        'fr',
        'de',
        '*'
      ]
    );
  });

  test('with duff q values', () => {
    assert.deepStrictEqual(
      acceptedLanguages('en;q=no, fr;z=0.9, de;q=0.7;q=9, *;q=0.5, fr-CH;q=a=0.1'), [
        'en',
        'fr',
        'fr-CH',
        'de',
        '*'
      ]
    );
  });

  test('with empty entries', () => {
    assert.deepStrictEqual(
      acceptedLanguages('en;q=0.8,,, fr;q=0.9,, de;q=0.7, *;q=0.5, fr-CH'), [
        'fr-CH',
        'fr',
        'en',
        'de',
        '*'
      ]
    );
  });

  test('edge cases', () => {
    const args = [
      null,
      NaN,
      Infinity,
      [],
      {}
    ];

    args.forEach(arg => {
      assert.throws(acceptedLanguages.bind(null, arg), TypeError);
    });
  });
});