element-web/test/unit-tests/theme-test.ts

/*
Copyright 2024 New Vector Ltd.
Copyright 2022 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 SettingsStore from "../../src/settings/SettingsStore";
import { enumerateThemes, getOrderedThemes, setTheme } from "../../src/theme";

describe("theme", () => {
    afterEach(() => {
        jest.restoreAllMocks();
    });

    describe("setTheme", () => {
        let lightTheme: HTMLStyleElement;
        let darkTheme: HTMLStyleElement;
        let lightCustomTheme: HTMLStyleElement;

        let spyQuerySelectorAll: jest.MockInstance<NodeListOf<Element>, [selectors: string]>;
        let spyClassList: jest.SpyInstance<void, string[], any>;

        beforeEach(() => {
            const styles = ["light", "dark", "light-custom", "dark-custom"].map(
                (theme) =>
                    ({
                        dataset: {
                            mxTheme: theme,
                        },
                        disabled: true,
                        href: "fake URL",
                        onload: (): void => void 0,
                    }) as unknown as HTMLStyleElement,
            );
            lightTheme = styles[0];
            darkTheme = styles[1];
            lightCustomTheme = styles[2];

            jest.spyOn(document.body, "style", "get").mockReturnValue([] as any);
            spyQuerySelectorAll = jest.spyOn(document, "querySelectorAll").mockReturnValue(styles as any);
            spyClassList = jest.spyOn(document.body.classList, "add");
        });

        afterEach(() => {
            jest.useRealTimers();
        });

        it("should switch theme on onload call", async () => {
            // When
            await new Promise((resolve) => {
                setTheme("light").then(resolve);
                lightTheme.onload!({} as Event);
            });

            // Then
            expect(spyQuerySelectorAll).toHaveBeenCalledWith("[data-mx-theme]");
            expect(spyQuerySelectorAll).toHaveBeenCalledTimes(1);
            expect(lightTheme.disabled).toBe(false);
            expect(darkTheme.disabled).toBe(true);
            expect(spyClassList).toHaveBeenCalledWith("cpd-theme-light");
        });

        it("should switch to dark", async () => {
            // When
            await new Promise((resolve) => {
                setTheme("dark").then(resolve);
                darkTheme.onload!({} as Event);
            });

            // Then
            expect(spyClassList).toHaveBeenCalledWith("cpd-theme-dark");
        });

        it("should reject promise on onerror call", () => {
            return expect(
                new Promise((resolve) => {
                    setTheme("light").catch((e) => resolve(e));
                    lightTheme.onerror!("call onerror");
                }),
            ).resolves.toBe("call onerror");
        });

        it("should switch theme if CSS are preloaded", async () => {
            // When
            jest.spyOn(document, "styleSheets", "get").mockReturnValue([lightTheme] as any);

            await setTheme("light");

            // Then
            expect(lightTheme.disabled).toBe(false);
            expect(darkTheme.disabled).toBe(true);
        });

        it("should switch theme if CSS is loaded during pooling", async () => {
            // When
            jest.useFakeTimers();
            await new Promise((resolve) => {
                setTheme("light").then(resolve);
                jest.spyOn(document, "styleSheets", "get").mockReturnValue([lightTheme] as any);
                jest.advanceTimersByTime(200);
            });

            // Then
            expect(lightTheme.disabled).toBe(false);
            expect(darkTheme.disabled).toBe(true);
        });

        it("should reject promise if pooling maximum value is reached", () => {
            jest.useFakeTimers();
            return new Promise((resolve) => {
                setTheme("light").catch(resolve);
                jest.advanceTimersByTime(200 * 10);
            });
        });

        it("applies a custom Compound theme", async () => {
            jest.spyOn(SettingsStore, "getValue").mockReturnValue([
                {
                    name: "blue",
                    compound: {
                        "--cpd-color-icon-accent-tertiary": "var(--cpd-color-blue-800)",
                        "--cpd-color-text-action-accent": "var(--cpd-color-blue-900)",
                    },
                },
            ]);

            const spy = jest.spyOn(document.head, "appendChild").mockImplementation();
            await new Promise((resolve) => {
                setTheme("custom-blue").then(resolve);
                lightCustomTheme.onload!({} as Event);
            });
            expect(spy).toHaveBeenCalled();
            expect(spy.mock.calls[0][0].textContent).toMatchSnapshot();
            spy.mockRestore();
        });
    });

    describe("enumerateThemes", () => {
        it("should return a list of themes", () => {
            jest.spyOn(SettingsStore, "getValue").mockReturnValue([{ name: "pink" }]);
            expect(enumerateThemes()).toEqual({
                "light": "Light",
                "light-high-contrast": "Light high contrast",
                "dark": "Dark",
                "custom-pink": "pink",
            });
        });

        it("should be robust to malformed custom_themes values", () => {
            jest.spyOn(SettingsStore, "getValue").mockReturnValue([23]);
            expect(enumerateThemes()).toEqual({
                "light": "Light",
                "light-high-contrast": "Light high contrast",
                "dark": "Dark",
            });
        });
    });

    describe("getOrderedThemes", () => {
        it("should return a list of themes in the correct order", () => {
            jest.spyOn(SettingsStore, "getValue").mockReturnValue([{ name: "Zebra Striped" }, { name: "Apple Green" }]);
            expect(getOrderedThemes()).toEqual([
                { id: "light", name: "Light" },
                { id: "dark", name: "Dark" },
                { id: "custom-Apple Green", name: "Apple Green" },
                { id: "custom-Zebra Striped", name: "Zebra Striped" },
            ]);
        });
    });
});