maplibre-gl/src/geo/projection/projection_factory.test.ts

BSD licensed community fork of mapbox-gl, a WebGL interactive maps library

import {afterEach, beforeEach, describe, test, expect, vi} from 'vitest';
import {createProjectionFromName} from './projection_factory.ts';
import {addProjection, removeProjection} from './projection_crud.ts';
import {MercatorProjection} from './mercator_projection.ts';
import {MercatorTransform} from './mercator_transform.ts';
import {MercatorCameraHelper} from './mercator_camera_helper.ts';

afterEach(() => {
    removeProjection('test:factory');
    vi.restoreAllMocks();
});

describe('createProjectionFromName', () => {
    test('resolves the built-in identity projection to a mercator projection named identity', () => {
        const {projection} = createProjectionFromName('identity', undefined, {});
        expect(projection).toBeInstanceOf(MercatorProjection);
        expect(projection.name).toBe('identity');
    });

    test('runs the identity projection on the mercator transform and camera helper over a non-wrapping world', () => {
        const {transform, cameraHelper} = createProjectionFromName('identity', undefined, {});
        expect(transform).toBeInstanceOf(MercatorTransform);
        expect(transform.worldCoordinateHelper.wraps).toBe(false);
        expect(cameraHelper).toBeInstanceOf(MercatorCameraHelper);
    });

    test('falls back to mercator for a name that only Object.prototype has', () => {
        vi.spyOn(console, 'warn').mockImplementation(() => {});
        const {projection} = createProjectionFromName('constructor', undefined, {});
        expect(projection.name).toBe('mercator');
    });

    test('does not warn for a projection expression of built-in projections', () => {
        const warn = vi.spyOn(console, 'warn').mockImplementation(() => {});
        createProjectionFromName(['interpolate', ['linear'], ['zoom'], 10, 'vertical-perspective', 12, 'mercator'], undefined, {});
        expect(warn).not.toHaveBeenCalled();
    });

    describe('for a registered CRS', () => {
        beforeEach(() => {
            addProjection({
                name: 'test:factory',
                projection: {forward: ([lng, lat]) => [lng * 2, lat * 2], inverse: ([x, y]) => [x / 2, y / 2]},
                tileMatrixSet: {origin: [-180, 180], extentAtZoom0: 360},
            });
        });

        test('resolves its name to a mercator projection under that name over its definition', () => {
            const {projection} = createProjectionFromName('test:factory', undefined, {});
            expect(projection).toBeInstanceOf(MercatorProjection);
            expect(projection.name).toBe('test:factory');
            const world = projection.worldCoordinateHelper.worldFromLngLat(90, 90);
            expect([world.x, world.y]).toEqual([1, 0]);
        });

        test('runs its transform on the projection\'s own mapping', () => {
            const {projection, transform} = createProjectionFromName('test:factory', undefined, {});
            expect(transform.worldCoordinateHelper).toBe(projection.worldCoordinateHelper);
        });

        test('warns that a projection expression naming it falls back to the globe projection', () => {
            const warn = vi.spyOn(console, 'warn').mockImplementation(() => {});
            createProjectionFromName(['step', ['zoom'], 'test:factory', 10, 'mercator'], undefined, {});
            expect(warn).toHaveBeenCalledWith('Projection expressions cannot use the registered projection "test:factory", which only works as a plain name. Falling back to the globe projection.');
        });
    });
});