docusaurus/packages/docusaurus-theme-common/src/utils/__tests__/tocUtils.test.ts

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

import type {TOCItem} from '@docusaurus/types';
import {filterTOC} from '../tocUtils';

describe('filterTOC', () => {
  test('filter a toc with all heading levels', () => {
    const toc: TOCItem[] = [
      {
        id: 'alpha',
        level: 1,
        value: 'alpha',
        children: [
          {
            id: 'bravo',
            level: 2,
            value: 'Bravo',
            children: [
              {
                id: 'charlie',
                level: 3,
                value: 'Charlie',
                children: [
                  {
                    id: 'delta',
                    level: 4,
                    value: 'Delta',
                    children: [
                      {
                        id: 'echo',
                        level: 5,
                        value: 'Echo',
                        children: [
                          {
                            id: 'foxtrot',
                            level: 6,
                            value: 'Foxtrot',
                            children: [],
                          },
                        ],
                      },
                    ],
                  },
                ],
              },
            ],
          },
        ],
      },
    ];

    expect(filterTOC({toc, minHeadingLevel: 2, maxHeadingLevel: 2})).toEqual([
      {
        id: 'bravo',
        level: 2,
        value: 'Bravo',
        children: [],
      },
    ]);

    expect(filterTOC({toc, minHeadingLevel: 3, maxHeadingLevel: 3})).toEqual([
      {
        id: 'charlie',
        level: 3,
        value: 'Charlie',
        children: [],
      },
    ]);

    expect(filterTOC({toc, minHeadingLevel: 2, maxHeadingLevel: 3})).toEqual([
      {
        id: 'bravo',
        level: 2,
        value: 'Bravo',
        children: [
          {
            id: 'charlie',
            level: 3,
            value: 'Charlie',
            children: [],
          },
        ],
      },
    ]);

    expect(filterTOC({toc, minHeadingLevel: 2, maxHeadingLevel: 4})).toEqual([
      {
        id: 'bravo',
        level: 2,
        value: 'Bravo',
        children: [
          {
            id: 'charlie',
            level: 3,
            value: 'Charlie',
            children: [
              {
                id: 'delta',
                level: 4,
                value: 'Delta',
                children: [],
              },
            ],
          },
        ],
      },
    ]);
  });

  // It's not 100% clear exactly how the TOC should behave under weird heading levels provided by the user
  // Adding a test so that behavior stays the same over time
  test('filter invalid heading levels (but possible) TOC', () => {
    const toc: TOCItem[] = [
      {
        id: 'charlie',
        level: 3,
        value: 'Charlie',
        children: [],
      },
      {
        id: 'bravo',
        level: 2,
        value: 'Bravo',
        children: [
          {
            id: 'delta',
            level: 4,
            value: 'Delta',
            children: [],
          },
        ],
      },
    ];

    expect(filterTOC({toc, minHeadingLevel: 2, maxHeadingLevel: 2})).toEqual([
      {
        id: 'bravo',
        level: 2,
        value: 'Bravo',
        children: [],
      },
    ]);

    expect(filterTOC({toc, minHeadingLevel: 3, maxHeadingLevel: 3})).toEqual([
      {
        id: 'charlie',
        level: 3,
        value: 'Charlie',
        children: [],
      },
    ]);

    expect(filterTOC({toc, minHeadingLevel: 4, maxHeadingLevel: 4})).toEqual([
      {
        id: 'delta',
        level: 4,
        value: 'Delta',
        children: [],
      },
    ]);

    expect(filterTOC({toc, minHeadingLevel: 2, maxHeadingLevel: 3})).toEqual([
      {
        id: 'charlie',
        level: 3,
        value: 'Charlie',
        children: [],
      },
      {
        id: 'bravo',
        level: 2,
        value: 'Bravo',
        children: [],
      },
    ]);

    expect(filterTOC({toc, minHeadingLevel: 3, maxHeadingLevel: 4})).toEqual([
      {
        id: 'charlie',
        level: 3,
        value: 'Charlie',
        children: [],
      },
      {
        id: 'delta',
        level: 4,
        value: 'Delta',
        children: [],
      },
    ]);
  });
});