element-web/test/PosthogAnalytics-test.ts

/*
Copyright 2021 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import { mocked } from 'jest-mock';
import { PostHog } from 'posthog-js';

import {
    Anonymity,

    getRedactedCurrentLocation,
    IPosthogEvent,
    PosthogAnalytics,
} from '../src/PosthogAnalytics';
import SdkConfig from '../src/SdkConfig';
import { getMockClientWithEventEmitter } from './test-utils';

const getFakePosthog = (): PostHog => ({
    capture: jest.fn(),
    init: jest.fn(),
    identify: jest.fn(),
    reset: jest.fn(),
    register: jest.fn(),
} as unknown as PostHog);

export interface ITestEvent extends IPosthogEvent {
    eventName: "JestTestEvents";
    foo: string;
}

describe("PosthogAnalytics", () => {
    let fakePosthog: PostHog;
    const shaHashes = {
        "42": "73475cb40a568e8da8a045ced110137e159f890ac4da883b6b17dc651b3a8049",
        "some": "a6b46dd0d1ae5e86cbc8f37e75ceeb6760230c1ca4ffbcb0c97b96dd7d9c464b",
        "pii": "bd75b3e080945674c0351f75e0db33d1e90986fa07b318ea7edf776f5eef38d4",
        "foo": "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae",
    };

    beforeEach(() => {
        fakePosthog = getFakePosthog();

        window.crypto = {
            subtle: {
                digest: async (_, encodedMessage) => {
                    const message = new TextDecoder().decode(encodedMessage);
                    const hexHash = shaHashes[message];
                    const bytes = [];
                    for (let c = 0; c < hexHash.length; c += 2) {
                        bytes.push(parseInt(hexHash.substr(c, 2), 16));
                    }
                    return bytes as unknown as ArrayBuffer;
                },
            } as unknown as SubtleCrypto,
        } as unknown as Crypto;
    });

    afterEach(() => {
        window.crypto = null;
        SdkConfig.unset(); // we touch the config, so clean up
    });

    describe("Initialisation", () => {
        it("Should not be enabled without config being set", () => {
            // force empty/invalid state for posthog options
            SdkConfig.put({ brand: "Testing" });
            const analytics = new PosthogAnalytics(fakePosthog);
            expect(analytics.isEnabled()).toBe(false);
        });

        it("Should be enabled if config is set", () => {
            SdkConfig.put({
                brand: "Testing",
                posthog: {
                    project_api_key: "foo",
                    api_host: "bar",
                },
            });
            const analytics = new PosthogAnalytics(fakePosthog);
            analytics.setAnonymity(Anonymity.Pseudonymous);
            expect(analytics.isEnabled()).toBe(true);
        });
    });

    describe("Tracking", () => {
        let analytics: PosthogAnalytics;

        beforeEach(() => {
            SdkConfig.put({
                brand: "Testing",
                posthog: {
                    project_api_key: "foo",
                    api_host: "bar",
                },
            });

            analytics = new PosthogAnalytics(fakePosthog);
        });

        it("Should pass event to posthog", () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
                foo: "bar",
            });
            expect(mocked(fakePosthog).capture.mock.calls[0][0]).toBe("JestTestEvents");
            expect(mocked(fakePosthog).capture.mock.calls[0][1]["foo"]).toEqual("bar");
        });

        it("Should not track events if anonymous", async () => {
            analytics.setAnonymity(Anonymity.Anonymous);
            await analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
                foo: "bar",
            });
            expect(fakePosthog.capture).not.toHaveBeenCalled();
        });

        it("Should not track any events if disabled", async () => {
            analytics.setAnonymity(Anonymity.Disabled);
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
                foo: "bar",
            });
            expect(fakePosthog.capture).not.toHaveBeenCalled();
        });

        it("Should anonymise location of a known screen", async () => {
            const location = getRedactedCurrentLocation("https://foo.bar", "#/register/some/pii", "/");
            expect(location).toBe("https://foo.bar/#/register/<redacted>");
        });

        it("Should anonymise location of an unknown screen", async () => {
            const location = getRedactedCurrentLocation("https://foo.bar", "#/not_a_screen_name/some/pii", "/");
            expect(location).toBe("https://foo.bar/#/<redacted_screen_name>/<redacted>");
        });

        it("Should handle an empty hash", async () => {
            const location = getRedactedCurrentLocation("https://foo.bar", "", "/");
            expect(location).toBe("https://foo.bar/");
        });

        it("Should identify the user to posthog if pseudonymous", async () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);
            const client = getMockClientWithEventEmitter({
                getAccountDataFromServer: jest.fn().mockResolvedValue(null),
                setAccountData: jest.fn().mockResolvedValue({}),
            });
            await analytics.identifyUser(client, () => "analytics_id");
            expect(mocked(fakePosthog).identify.mock.calls[0][0]).toBe("analytics_id");
        });

        it("Should not identify the user to posthog if anonymous", async () => {
            analytics.setAnonymity(Anonymity.Anonymous);
            const client = getMockClientWithEventEmitter({});
            await analytics.identifyUser(client, () => "analytics_id");
            expect(mocked(fakePosthog).identify.mock.calls.length).toBe(0);
        });

        it("Should identify using the server's analytics id if present", async () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);

            const client = getMockClientWithEventEmitter({
                getAccountDataFromServer: jest.fn().mockResolvedValue({ id: "existing_analytics_id" }),
                setAccountData: jest.fn().mockResolvedValue({}),
            });
            await analytics.identifyUser(client, () => "new_analytics_id");
            expect(mocked(fakePosthog).identify.mock.calls[0][0]).toBe("existing_analytics_id");
        });
    });
});