element-web/test/unit-tests/utils/iterables-test.ts

/*
Copyright 2024 New Vector Ltd.
Copyright 2021 The Matrix.org Foundation C.I.C.

SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/

import { iterableDiff, iterableIntersection } from "../../../src/utils/iterables";

describe("iterables", () => {
    describe("iterableIntersection", () => {
        it("should return the intersection", () => {
            const a = [1, 2, 3];
            const b = [1, 2, 4]; // note diff
            const result = iterableIntersection(a, b);
            expect(result).toBeDefined();
            expect(result).toHaveLength(2);
            expect(result).toEqual([1, 2]);
        });

        it("should return an empty array on no matches", () => {
            const a = [1, 2, 3];
            const b = [4, 5, 6];
            const result = iterableIntersection(a, b);
            expect(result).toBeDefined();
            expect(result).toHaveLength(0);
        });
    });

    describe("iterableDiff", () => {
        it("should see added from A->B", () => {
            const a = [1, 2, 3];
            const b = [1, 2, 3, 4];
            const result = iterableDiff(a, b);
            expect(result).toBeDefined();
            expect(result.added).toBeDefined();
            expect(result.removed).toBeDefined();
            expect(result.added).toHaveLength(1);
            expect(result.removed).toHaveLength(0);
            expect(result.added).toEqual([4]);
        });

        it("should see removed from A->B", () => {
            const a = [1, 2, 3];
            const b = [1, 2];
            const result = iterableDiff(a, b);
            expect(result).toBeDefined();
            expect(result.added).toBeDefined();
            expect(result.removed).toBeDefined();
            expect(result.added).toHaveLength(0);
            expect(result.removed).toHaveLength(1);
            expect(result.removed).toEqual([3]);
        });

        it("should see added and removed in the same set", () => {
            const a = [1, 2, 3];
            const b = [1, 2, 4]; // note diff
            const result = iterableDiff(a, b);
            expect(result).toBeDefined();
            expect(result.added).toBeDefined();
            expect(result.removed).toBeDefined();
            expect(result.added).toHaveLength(1);
            expect(result.removed).toHaveLength(1);
            expect(result.added).toEqual([4]);
            expect(result.removed).toEqual([3]);
        });
    });
});