@maplibre/maplibre-gl-style-spec/src/group_by_layout.test.ts

a specification for maplibre styles

import {groupByLayout} from './group_by_layout';
import {describe, test, expect} from 'vitest';
import type {LayerSpecification} from './types.g';

describe('group by layout', () => {
    test('group layers whose ref properties are identical', () => {
        const a = {
            id: 'parent',
            type: 'line'
        } as LayerSpecification;
        const b = {
            id: 'child',
            type: 'line'
        } as LayerSpecification;
        expect(groupByLayout([a, b], {})).toEqual([[a, b]]);
        expect(groupByLayout([a, b], {})[0][0]).toBe(a);
        expect(groupByLayout([a, b], {})[0][1]).toBe(b);
    });

    test('group does not group unrelated layers', () => {
        expect(
            groupByLayout(
                [
                    {
                        id: 'parent',
                        type: 'line'
                    } as LayerSpecification,
                    {
                        id: 'child',
                        type: 'fill'
                    } as LayerSpecification
                ],
                {}
            )
        ).toEqual([
            [
                {
                    id: 'parent',
                    type: 'line'
                }
            ],
            [
                {
                    id: 'child',
                    type: 'fill'
                }
            ]
        ]);
    });

    test('group works even for differing layout key orders', () => {
        expect(
            groupByLayout(
                [
                    {
                        id: 'parent',
                        type: 'line',
                        layout: {a: 1, b: 2}
                    } as any as LayerSpecification,
                    {
                        id: 'child',
                        type: 'line',
                        layout: {b: 2, a: 1}
                    } as any as LayerSpecification
                ],
                {}
            )
        ).toEqual([
            [
                {
                    id: 'parent',
                    type: 'line',
                    layout: {a: 1, b: 2}
                },
                {
                    id: 'child',
                    type: 'line',
                    layout: {b: 2, a: 1}
                }
            ]
        ]);
    });
});