index.test.ts

import { FetchMock } from 'jest-fetch-mock';
import 'jest-localstorage-mock';
import * as data from './test/testdata.json';
import IStorageProvider from './storage-provider';
import {
    EVENTS,
    IConfig,
    IMutableContext,
    IToggle,
    InMemoryStorageProvider,
    UnleashClient,
    lastUpdateKey,
} from './index';
import { getTypeSafeRequest, getTypeSafeRequestUrl } from './test';
import Metrics from './metrics';

jest.useFakeTimers();

const fetchMock = fetch as FetchMock;

afterEach(() => {
    fetchMock.resetMocks();
    jest.clearAllTimers();
});

test('Should initialize unleash-client', () => {
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    new UnleashClient(config);
    expect(config.url).toBe('http://localhost/test');
});

test('Should perform an initial fetch', async () => {
    fetchMock.mockResponseOnce(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    await client.start();
    const isEnabled = client.isEnabled('simpleToggle');
    client.stop();
    expect(isEnabled).toBe(true);
});

test('Should perform an initial fetch as POST', async () => {
    fetchMock.mockResponseOnce(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'webAsPOST',
        usePOSTrequests: true,
    };
    const client = new UnleashClient(config);
    await client.start();

    const request = getTypeSafeRequest(fetchMock, 0);
    const body = JSON.parse(request.body as string);

    expect(request.method).toBe('POST');
    expect(body.context.appName).toBe('webAsPOST');
    expect(request.headers).toMatchObject({
        'content-type': 'application/json',
    });
});

test('Should perform an initial fetch as GET', async () => {
    fetchMock.mockResponseOnce(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'webAsGET',
    };
    const client = new UnleashClient(config);
    await client.start();

    const request = getTypeSafeRequest(fetchMock, 0);

    expect(request.method).toBe('GET');
    expect(request.headers).not.toMatchObject({
        'Content-Type': 'application/json',
    });
});

test('Should have correct variant', async () => {
    fetchMock.mockResponseOnce(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    await client.start();
    const variant = client.getVariant('variantToggle');
    const payload = variant.payload || { type: 'undef', value: '' };
    client.stop();
    expect(variant.name).toBe('green');
    expect(variant.enabled).toBe(true);
    expect(variant.feature_enabled).toBe(true);
    expect(payload.type).toBe('string');
    expect(payload.value).toBe('some-text');
});

test('Should return default variant if not found', async () => {
    fetchMock.mockResponseOnce(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    await client.start();
    const variant = client.getVariant('missingToggle');
    const payload = variant.payload || { type: 'undef', value: '' };
    client.stop();
    expect(variant.name).toBe('disabled');
    expect(variant.enabled).toBe(false);
    expect(variant.feature_enabled).toBe(false);
    expect(payload.type).toBe('undef');
    expect(payload.value).toBe('');
});

test('Should handle error and return false for isEnabled', async () => {
    jest.spyOn(global.console, 'error').mockImplementation(() => jest.fn());
    fetchMock.mockReject();

    class Store implements IStorageProvider {
        public async save() {
            return Promise.resolve();
        }

        public async get() {
            return Promise.resolve([]);
        }
    }

    const storageProvider = new Store();
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        storageProvider,
    };
    const client = new UnleashClient(config);
    await client.start();
    const isEnabled = client.isEnabled('simpleToggle');
    client.stop();
    expect(isEnabled).toBe(false);
});

test('Should read session id from localStorage', async () => {
    const sessionId = '123';
    fetchMock.mockReject();

    class Store implements IStorageProvider {
        public async save() {
            return Promise.resolve();
        }

        public async get(name: string) {
            if (name === 'sessionId') {
                return sessionId;
            }
            return Promise.resolve([]);
        }
    }

    const storageProvider = new Store();
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        storageProvider,
    };
    const client = new UnleashClient(config);
    await client.start();
    const context = client.getContext();
    expect(context.sessionId).toBe(sessionId);
});

test('Should send sessionId as string, even if it was saved a number', async () => {
    const sessionId = 123;
    fetchMock.mockReject();

    class Store implements IStorageProvider {
        public async save() {
            return Promise.resolve();
        }

        public async get(name: string) {
            if (name === 'sessionId') {
                return sessionId;
            }
            return Promise.resolve([]);
        }
    }

    const storageProvider = new Store();
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        storageProvider,
    };
    const client = new UnleashClient(config);
    await client.start();
    const context = client.getContext();
    expect(context.sessionId).toBe('123');
});
test('Should read toggles from localStorage', async () => {
    jest.spyOn(global.console, 'error').mockImplementation(() => jest.fn());
    const toggles = [
        {
            name: 'featureToggleBackup',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
        },
    ];
    fetchMock.mockReject();

    class Store implements IStorageProvider {
        public async save() {
            return Promise.resolve();
        }

        public async get(name: string) {
            if (name === 'repo') {
                return Promise.resolve(toggles);
            } else {
                return Promise.resolve(undefined);
            }
        }
    }

    const storageProvider = new Store();
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        storageProvider,
    };
    const client = new UnleashClient(config);
    await client.start();
    expect(client.isEnabled('featureToggleBackup')).toBe(true);
    expect(client.isEnabled('featureUnknown')).toBe(false);
});

test('Should bootstrap data when bootstrap is provided', async () => {
    localStorage.clear();
    const storeKey = 'unleash:repository:repo';
    const bootstrap = [
        {
            name: 'toggles',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'algo',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];
    const initialData = [
        {
            name: 'initialData',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'test initial',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    localStorage.setItem(storeKey, JSON.stringify(initialData));
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(initialData));

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
    };
    const client = new UnleashClient(config);
    await client.start();

    expect(client.getAllToggles()).toStrictEqual(bootstrap);
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(bootstrap));
});

test('Should set internal toggle state when bootstrap is set, before client is started', async () => {
    localStorage.clear();
    const storeKey = 'unleash:repository:repo';
    const bootstrap = [
        {
            name: 'toggles',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'algo',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];
    const initialData = [
        {
            name: 'initialData',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'test initial',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    localStorage.setItem(storeKey, JSON.stringify(initialData));
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(initialData));

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
    };
    const client = new UnleashClient(config);
    expect(client.getAllToggles()).toStrictEqual(bootstrap);
    await client.start();
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(bootstrap));
});

test('Should not bootstrap data when bootstrapOverride is false and localStorage is not empty', async () => {
    localStorage.clear();
    const storeKey = 'unleash:repository:repo';
    const bootstrap = [
        {
            name: 'toggles',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'algo',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];
    const initialData = [
        {
            name: 'initialData',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'test initial',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    localStorage.setItem(storeKey, JSON.stringify(initialData));
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(initialData));

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
        bootstrapOverride: false,
    };
    const client = new UnleashClient(config);
    await client.start();

    expect(client.getAllToggles()).toStrictEqual(initialData);
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(initialData));
});

test('Should bootstrap when bootstrapOverride is false and local storage is empty', async () => {
    localStorage.clear();
    const storeKey = 'unleash:repository:repo';
    const bootstrap = [
        {
            name: 'toggles',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'algo',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    localStorage.setItem(storeKey, JSON.stringify([]));
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify([]));

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
        bootstrapOverride: false,
    };
    const client = new UnleashClient(config);
    await client.start();

    expect(client.getAllToggles()).toStrictEqual(bootstrap);
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(bootstrap));
});

test('Should not bootstrap data when bootstrap is []', async () => {
    localStorage.clear();
    const storeKey = 'unleash:repository:repo';
    const initialData = [
        {
            name: 'initialData',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
        },
        {
            name: 'test initial',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
        },
    ];

    localStorage.setItem(storeKey, JSON.stringify(initialData));
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(initialData));

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap: [],
        bootstrapOverride: true,
    };
    const client = new UnleashClient(config);
    await client.start();

    expect(client.getAllToggles()).toStrictEqual(initialData);
    expect(localStorage.getItem(storeKey)).toBe(JSON.stringify(initialData));
});

test('Should publish ready event when bootstrap is provided, before client is started', async () => {
    localStorage.clear();
    const bootstrap = [
        {
            name: 'toggles',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
        {
            name: 'algo',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
    };
    const client = new UnleashClient(config);
    expect(client.getAllToggles()).toStrictEqual(bootstrap);
    client.on(EVENTS.READY, () => {
        expect(client.isEnabled('algo')).toBe(true);
    });
});

test('Should publish ready when initial fetch completed', (done) => {
    fetchMock.mockResponseOnce(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.start();
    client.on(EVENTS.READY, () => {
        const isEnabled = client.isEnabled('simpleToggle');
        client.stop();
        expect(isEnabled).toBe(true);
        done();
    });
});

test('Should publish error when initial init fails', (done) => {
    const givenError = 'Error';

    class Store implements IStorageProvider {
        public async save(): Promise<void> {
            return Promise.reject(givenError);
        }

        public async get(): Promise<any> {
            return Promise.reject(givenError);
        }
    }

    jest.spyOn(global.console, 'error').mockImplementation(() => jest.fn());
    fetchMock.mockResponseOnce(JSON.stringify(data));

    const storageProvider = new Store();
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        storageProvider,
    };
    const client = new UnleashClient(config);
    client.start();
    client.on(EVENTS.ERROR, (e: any) => {
        expect(e).toBe(givenError);
        done();
    });
});

test('Should publish error when fetch fails', (done) => {
    const givenError = new Error('Error');

    jest.spyOn(global.console, 'error').mockImplementation(() => jest.fn());
    fetchMock.mockReject(givenError);

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.start();
    client.on(EVENTS.ERROR, (e: any) => {
        expect(e).toBe(givenError);
        done();
    });
});

test('Should abort previous request', async () => {
    fetchMock.mockResponse(JSON.stringify(data));
    const abortSpy = jest.spyOn(AbortController.prototype, 'abort');

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);

    await client.start();
    client.updateContext({ userId: '123' }); // abort 1
    client.updateContext({ userId: '456' }); // abort 2
    await client.updateContext({ userId: '789' });

    expect(abortSpy).toHaveBeenCalledTimes(2);
    abortSpy.mockRestore();
});

test('Should not trigger error on abort', async () => {
    fetchMock.mockResponse(JSON.stringify(data));

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.on(EVENTS.ERROR, () => {
        throw new Error('abort should not trigger error');
    });

    await client.start();

    fetchMock.mockAbort();
    await client.updateContext({ userId: '789' });
});

test('Should run without abort controller', async () => {
    fetchMock.mockResponse(JSON.stringify(data));
    const abortSpy = jest.spyOn(AbortController.prototype, 'abort');

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        createAbortController: () => null,
    };
    const client = new UnleashClient(config);

    await client.start();
    client.updateContext({ userId: '123' });
    client.updateContext({ userId: '456' });
    await client.updateContext({ userId: '789' });

    expect(abortSpy).toHaveBeenCalledTimes(0);
    abortSpy.mockRestore();
});

test.each([400, 401, 403, 404, 429, 500, 502, 503])(
    'Should publish error when fetch receives a %d error',
    async (errorCode) => {
        expect.assertions(1);
        jest.spyOn(global.console, 'error').mockImplementation(() => jest.fn());
        fetchMock.mockResponseOnce('{}', { status: errorCode });

        const config: IConfig = {
            url: 'http://localhost/test',
            clientKey: '12',
            appName: 'web',
        };
        const client = new UnleashClient(config);
        client.on(EVENTS.ERROR, (e: any) => {
            expect(e).toStrictEqual({ type: 'HttpError', code: errorCode });
        });
        await client.start();
    }
);

test('Should publish update when state changes after refreshInterval', async () => {
    expect.assertions(1);
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        refreshInterval: 1,
        appName: 'web',
    };
    const client = new UnleashClient(config);

    let counts = 0;
    client.on(EVENTS.UPDATE, () => {
        counts++;
        if (counts === 2) {
            expect(fetchMock.mock.calls.length).toEqual(2);
            client.stop();
        }
    });

    await client.start();

    jest.advanceTimersByTime(1001);
});

test(`If refresh is disabled should not fetch`, async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const config: IConfig = {
        disableRefresh: true,
        url: 'http://localhost/test',
        clientKey: '12',
        refreshInterval: 1,
        appName: 'web',
    };
    const client = new UnleashClient(config);
    await client.start();
    jest.advanceTimersByTime(100000);
    expect(fetchMock.mock.calls.length).toEqual(1); // Never called again
});

test('Should include etag in second request', async () => {
    const etag = '123a';
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200, headers: { ETag: etag } }],
        [JSON.stringify(data), { status: 304, headers: { ETag: etag } }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        refreshInterval: 1,
        appName: 'web',
    };
    const client = new UnleashClient(config);

    await client.start();

    jest.advanceTimersByTime(1001);

    const firstRequest = getTypeSafeRequest(fetchMock, 0);
    const secondRequest = getTypeSafeRequest(fetchMock, 1);

    expect(firstRequest.headers).toMatchObject({});
    expect(secondRequest.headers).toMatchObject({
        'if-none-match': etag,
    });
});

test('Should add clientKey as Authorization header', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: 'some123key',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    await client.start();

    jest.advanceTimersByTime(1001);

    const request = getTypeSafeRequest(fetchMock);

    expect(request.headers).toMatchObject({
        authorization: 'some123key',
    });
});

test('Should require appName', () => {
    expect(() => {
        new UnleashClient({
            url: 'http://localhost/test',
            clientKey: '12',
            appName: '',
        });
    }).toThrow();
});

test('Should require url', () => {
    expect(() => {
        new UnleashClient({ url: '', clientKey: '12', appName: 'web' });
    }).toThrow();
});

test('Should require valid url', () => {
    expect(() => {
        new UnleashClient({
            url: 'not-a-url',
            clientKey: '12',
            appName: 'web',
        });
    }).toThrow();
});

test('Should require valid clientKey', () => {
    expect(() => {
        new UnleashClient({
            url: 'http://localhost/test',
            clientKey: '',
            appName: 'web',
        });
    }).toThrow();
});

test('Should stop fetching when stop is called', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        refreshInterval: 1,
        appName: 'web',
    };
    const client = new UnleashClient(config);

    await client.start();

    jest.advanceTimersByTime(1001);

    client.stop();

    jest.advanceTimersByTime(1001);
    jest.advanceTimersByTime(1001);
    jest.advanceTimersByTime(1001);

    expect(fetchMock.mock.calls.length).toEqual(2);
});

test('Should include context fields on request', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 304 }]
    );
    const context: IMutableContext = {
        userId: '123',
        sessionId: '456',
        remoteAddress: 'address',
        properties: {
            property1: 'property1',
            property2: 'property2',
        },
    };
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        environment: 'prod',
        context,
    };
    const client = new UnleashClient(config);

    await client.start();

    jest.advanceTimersByTime(1001);

    const url = new URL(getTypeSafeRequestUrl(fetchMock));

    expect(url.searchParams.get('userId')).toEqual('123');
    expect(url.searchParams.get('sessionId')).toEqual('456');
    expect(url.searchParams.get('remoteAddress')).toEqual('address');
    expect(url.searchParams.get('properties[property1]')).toEqual('property1');
    expect(url.searchParams.get('properties[property2]')).toEqual('property2');
    expect(url.searchParams.get('appName')).toEqual('web');
    expect(url.searchParams.get('environment')).toEqual('prod');
});

test('Should note include context fields with "null" value', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 304 }]
    );
    const context: IMutableContext = {
        userId: undefined,
        sessionId: '0',
        remoteAddress: undefined,
        properties: {
            property1: 'property1',
            property2: 'property2',
        },
    };
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        environment: 'prod',
        context,
    };
    const client = new UnleashClient(config);

    await client.start();

    jest.advanceTimersByTime(1001);

    const url = new URL(getTypeSafeRequestUrl(fetchMock));

    expect(url.searchParams.has('userId')).toBe(false);
    expect(url.searchParams.has('remoteAddress')).toBe(false);
    expect(url.searchParams.has('sessionId')).toBe(true);
    expect(url.searchParams.get('sessionId')).toBe('0');
});

test('Should update context fields with await', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 304 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        environment: 'prod',
    };
    const client = new UnleashClient(config);
    await client.updateContext({
        userId: '123',
        sessionId: '456',
        remoteAddress: 'address',
        properties: {
            property1: 'property1',
            property2: 'property2',
        },
    });

    await client.start();

    jest.advanceTimersByTime(1001);

    const url = new URL(getTypeSafeRequestUrl(fetchMock));

    expect(url.searchParams.get('userId')).toEqual('123');
    expect(url.searchParams.get('sessionId')).toEqual('456');
    expect(url.searchParams.get('remoteAddress')).toEqual('address');
    expect(url.searchParams.get('properties[property1]')).toEqual('property1');
    expect(url.searchParams.get('properties[property2]')).toEqual('property2');
    expect(url.searchParams.get('appName')).toEqual('web');
    expect(url.searchParams.get('environment')).toEqual('prod');
});

test('Should update context fields on request', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 304 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        environment: 'prod',
    };
    const client = new UnleashClient(config);
    client.updateContext({
        userId: '123',
        sessionId: '456',
        remoteAddress: 'address',
        properties: {
            property1: 'property1',
            property2: 'property2',
        },
    });

    await client.start();

    jest.advanceTimersByTime(1001);

    const url = new URL(getTypeSafeRequestUrl(fetchMock));

    expect(url.searchParams.get('userId')).toEqual('123');
    expect(url.searchParams.get('sessionId')).toEqual('456');
    expect(url.searchParams.get('remoteAddress')).toEqual('address');
    expect(url.searchParams.get('properties[property1]')).toEqual('property1');
    expect(url.searchParams.get('properties[property2]')).toEqual('property2');
    expect(url.searchParams.get('appName')).toEqual('web');
    expect(url.searchParams.get('environment')).toEqual('prod');
});

test('Updating context should wait on asynchronous start', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        environment: 'prod',
    };
    const client = new UnleashClient(config);

    client.start();
    await client.updateContext({
        userId: '123',
    });

    expect(fetchMock).toHaveBeenCalledTimes(2);
});

test('Should not replace sessionId when updating context', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 304 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        environment: 'prod',
    };
    const client = new UnleashClient(config);
    await client.start();
    const context = client.getContext();
    await client.updateContext({
        userId: '123',
        remoteAddress: 'address',
        properties: {
            property1: 'property1',
            property2: 'property2',
        },
    });

    jest.advanceTimersByTime(1001);

    const url = new URL(getTypeSafeRequestUrl(fetchMock));

    expect(url.searchParams.get('sessionId')).toEqual(
        context.sessionId?.toString()
    );
});

test('Should not add property fields when properties is an empty object', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 304 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        environment: 'prod',
        context: {
            properties: {},
        },
    };
    const client = new UnleashClient(config);

    await client.start();

    jest.advanceTimersByTime(1001);

    const url = new URL(getTypeSafeRequestUrl(fetchMock));

    // console.log(url.toString(), url.searchParams.toString(), url.searchParams.get('properties'));

    expect(url.searchParams.get('appName')).toEqual('web');
    expect(url.searchParams.get('environment')).toEqual('prod');
    expect(url.searchParams.get('properties')).toBeNull();
});

test('Should use default environment', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    await client.start();

    jest.advanceTimersByTime(1001);

    const url = new URL(getTypeSafeRequestUrl(fetchMock));

    expect(url.searchParams.get('environment')).toEqual('default');
});

test('Should setContextField with userId', async () => {
    const userId = 'some-id-123';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.setContextField('userId', userId);
    const context = client.getContext();
    expect(context.userId).toBe(userId);
});

test('Should removeContextField', async () => {
    const userId = 'some-id-123';
    const customValue = 'customValue';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.setContextField('userId', userId);
    client.setContextField('customField', customValue);

    client.removeContextField('userId');
    client.removeContextField('customField');
    const context = client.getContext();

    expect(context).toEqual({
        appName: 'web',
        environment: 'default',
        properties: {},
    });
});

test('Should setContextField with sessionId', async () => {
    const sessionId = 'some-session-id-123';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.setContextField('sessionId', sessionId);
    const context = client.getContext();
    expect(context.sessionId).toBe(sessionId);
});

test('Should setContextField with remoteAddress', async () => {
    const remoteAddress = '10.0.0.1';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.setContextField('remoteAddress', remoteAddress);
    const context = client.getContext();
    expect(context.remoteAddress).toBe(remoteAddress);
});

test('Should setContextField with currentTime', async () => {
    const currentTime = '2022-01-22T13:00:00.000Z';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.setContextField('currentTime', currentTime);
    const context = client.getContext();
    expect(context.currentTime).toBe(currentTime);
});

test('Should setContextField with custom property', async () => {
    const clientId = 'some-client-id-443';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    client.setContextField('clientId', clientId);
    const context = client.getContext();
    expect(context.properties?.clientId).toBe(clientId);
});

test('Should setContextField with custom property and keep existing props', async () => {
    const clientId = 'some-client-id-443';
    const initialContext = { properties: { someField: '123' } };
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        context: initialContext,
    };
    const client = new UnleashClient(config);
    client.setContextField('clientId', clientId);
    const context = client.getContext();
    expect(context.properties?.clientId).toBe(clientId);
    expect(context.properties?.someField).toBe(
        initialContext.properties.someField
    );
});

test('Should override userId via setContextField', async () => {
    const userId = 'some-user-id-552';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        context: { userId: 'old' },
    };
    const client = new UnleashClient(config);
    client.setContextField('userId', userId);
    const context = client.getContext();
    expect(context.userId).toBe(userId);
});

test('Initializing client twice should show a console warning', async () => {
    console.error = jest.fn();
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        context: { userId: 'old' },
    };
    const client = new UnleashClient(config);

    await client.start();
    await client.start();
    // Expect console.error to be called once before start runs.
    expect(console.error).toHaveBeenCalledTimes(2);
});

test('Should pass under custom header clientKey', async () => {
    fetchMock.mockResponseOnce(JSON.stringify(data));

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        headerName: 'NotAuthorization',
    };
    const client = new UnleashClient(config);

    client.on(EVENTS.UPDATE, () => {
        const request = getTypeSafeRequest(fetchMock, 0);

        expect(fetchMock.mock.calls.length).toEqual(1);
        expect(request.headers).toMatchObject({
            NotAuthorization: '12',
        });
        client.stop();
    });

    await client.start();

    jest.advanceTimersByTime(999);
});

test('Should emit impression events on isEnabled calls when impressionData is true', (done) => {
    const bootstrap = [
        {
            name: 'impression',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
    };
    const client = new UnleashClient(config);
    client.start();

    client.on(EVENTS.READY, () => {
        const isEnabled = client.isEnabled('impression');
        expect(isEnabled).toBe(true);
    });

    client.on(EVENTS.IMPRESSION, (event: any) => {
        expect(event.featureName).toBe('impression');
        expect(event.eventType).toBe('isEnabled');
        client.stop();
        done();
    });
});

test('Should pass custom headers', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: 'extrakey',
        appName: 'web',
        customHeaders: {
            customheader1: 'header1val',
            customheader2: 'header2val',
        },
    };
    const client = new UnleashClient(config);
    await client.start();

    jest.advanceTimersByTime(1001);

    const featureRequest = getTypeSafeRequest(fetchMock, 0);

    expect(featureRequest.headers).toMatchObject({
        customheader1: 'header1val',
        customheader2: 'header2val',
    });

    client.isEnabled('count-metrics');
    jest.advanceTimersByTime(2001);

    const metricsRequest = getTypeSafeRequest(fetchMock, 1);

    expect(metricsRequest.headers).toMatchObject({
        customheader1: 'header1val',
        customheader2: 'header2val',
    });
});

test('Should add unleash identification headers', async () => {
    fetchMock.mockResponses(
        [JSON.stringify(data), { status: 200 }],
        [JSON.stringify(data), { status: 200 }]
    );
    const appName = 'unleash-client-test';
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: 'some123key',
        appName,
    };
    const client = new UnleashClient(config);
    await client.start();

    const featureRequest = getTypeSafeRequest(fetchMock, 0);

    client.isEnabled('count-metrics');
    jest.advanceTimersByTime(2001);

    const metricsRequest = getTypeSafeRequest(fetchMock, 1);

    const uuidFormat =
        /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;

    const expectedHeaders = {
        // will be replaced at build time with the actual version
        'unleash-sdk': 'unleash-client-js:__VERSION__',
        'unleash-connection-id': expect.stringMatching(uuidFormat),
        'unleash-appname': appName,
    };

    const getConnectionId = (request: any) =>
        request.headers['unleash-connection-id'];

    expect(featureRequest.headers).toMatchObject(expectedHeaders);
    expect(metricsRequest.headers).toMatchObject(expectedHeaders);
    expect(getConnectionId(featureRequest)).toEqual(
        getConnectionId(metricsRequest)
    );
});

test('Should emit impression events on getVariant calls when impressionData is true', (done) => {
    const bootstrap = [
        {
            name: 'impression-variant',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
    };
    const client = new UnleashClient(config);
    client.start();

    client.on(EVENTS.READY, () => {
        const isEnabled = client.getVariant('impression-variant');
        expect(isEnabled).toBe(true);
    });

    client.on(EVENTS.IMPRESSION, (event: any) => {
        expect(event.featureName).toBe('impression-variant');
        expect(event.eventType).toBe('getVariant');
        expect(event.impressionData).toBe(true);
        client.stop();
        done();
    });
});

test('Should not emit impression events on isEnabled calls when impressionData is false', (done) => {
    const bootstrap = [
        {
            name: 'impression',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: false,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
    };
    const client = new UnleashClient(config);
    client.start();

    client.on(EVENTS.READY, () => {
        const isEnabled = client.isEnabled('impression');
        expect(isEnabled).toBe(true);
        client.stop();
        done();
    });

    client.on(EVENTS.IMPRESSION, () => {
        client.stop();
        fail('SDK should not emit impression event');
    });
});

test('Should emit impression events on isEnabled calls when impressionData is false and impressionDataAll is true', (done) => {
    const bootstrap = [
        {
            name: 'impression',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: false,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
        impressionDataAll: true,
    };
    const client = new UnleashClient(config);
    client.start();

    client.on(EVENTS.READY, () => {
        const isEnabled = client.isEnabled('impression');
        expect(isEnabled).toBe(true);
    });

    client.on(EVENTS.IMPRESSION, (event: any) => {
        try {
            expect(event.featureName).toBe('impression');
            expect(event.eventType).toBe('isEnabled');
            expect(event.impressionData).toBe(false);
            client.stop();
            done();
        } catch (e) {
            client.stop();
            done(e);
        }
    });
});

test('Should emit impression events on isEnabled calls when toggle is unknown and impressionDataAll is true', (done) => {
    const bootstrap = [
        {
            name: 'impression',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: false,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
        impressionDataAll: true,
    };
    const client = new UnleashClient(config);
    client.start();

    client.on(EVENTS.READY, () => {
        const isEnabled = client.isEnabled('unknown');
        expect(isEnabled).toBe(true);
    });

    client.on(EVENTS.IMPRESSION, (event: any) => {
        expect(event.featureName).toBe('unknown');
        expect(event.eventType).toBe('isEnabled');
        expect(event.enabled).toBe(false);
        expect(event.impressionData).toBe(undefined);
        client.stop();
        done();
    });
});

test('Should emit impression events on getVariant calls when impressionData is false and impressionDataAll is true', (done) => {
    const bootstrap = [
        {
            name: 'impression-variant',
            enabled: true,
            variant: {
                name: 'disabled',
                enabled: false,
                feature_enabled: true,
            },
            impressionData: false,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap,
        impressionDataAll: true,
    };
    const client = new UnleashClient(config);
    client.start();

    client.on(EVENTS.READY, () => {
        const isEnabled = client.getVariant('impression-variant');
        expect(isEnabled).toBe(true);
    });

    client.on(EVENTS.IMPRESSION, (event: any) => {
        try {
            expect(event.featureName).toBe('impression-variant');
            expect(event.eventType).toBe('getVariant');
            expect(event.impressionData).toBe(false);
            client.stop();
            done();
        } catch (e) {
            client.stop();
            done(e);
        }
    });
});

test('Should publish ready only when the first fetch was successful', async () => {
    fetchMock.mockResponse(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        refreshInterval: 1,
    };
    const client = new UnleashClient(config);
    await client.start();

    let readyCount = 0;

    client.on(EVENTS.READY, () => {
        const isEnabled = client.isEnabled('simpleToggle');
        expect(isEnabled).toBe(true);
        readyCount++;
        client.stop();
        expect(readyCount).toEqual(1);
    });

    jest.advanceTimersByTime(1001);
    jest.advanceTimersByTime(1001);

    expect(fetchMock).toHaveBeenCalledTimes(3);
});

test('Should be able to configure UnleashClient with a URL instance', () => {
    const url = new URL('test', 'http://localhost');
    const config: IConfig = {
        url,
        clientKey: '12',
        appName: 'web',
    };
    const client = new UnleashClient(config);
    expect(client).toHaveProperty('url', url);
});

test("Should update toggles even when refresh interval is set to '0'", async () => {
    fetchMock.mockResponse(JSON.stringify(data));
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        refreshInterval: 0,
    };
    const client = new UnleashClient(config);
    await client.start();
    expect(fetchMock).toHaveBeenCalledTimes(1);

    await client.updateContext({ userId: '123' });
    expect(fetchMock).toHaveBeenCalledTimes(2);
});

test.each([null, undefined])(
    'Setting a context field to %s should clear it from the context',
    async () => {
        fetchMock.mockResponse(JSON.stringify(data));
        const config: IConfig = {
            url: 'http://localhost/test',
            clientKey: '12',
            appName: 'web',
        };
        const client = new UnleashClient(config);
        await client.start();

        await client.updateContext({ userId: '123' });
        expect(client.getContext().userId).toEqual('123');

        const userId = undefined;
        await client.updateContext({ userId });

        expect(client.getContext().userId).toBeUndefined();
    }
);

test('Should report metrics', async () => {
    const toggles: IToggle[] = [
        {
            name: 'toggle',
            enabled: true,
            variant: {
                name: 'variant',
                enabled: true,
                feature_enabled: true,
            },
            impressionData: true,
        },
    ];

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        fetch: async () => {
            return {
                ok: true,
                headers: new Map(),
                async json() {
                    return { toggles };
                },
            };
        },
    };
    const client = new UnleashClient(config);
    await client.start();

    client.getVariant('toggle');
    client.getVariant('non-existent-toggle');
    jest.advanceTimersByTime(2500); // fist metric sent after 2 seconds

    const data = await new Promise((resolve) => {
        client.on(EVENTS.SENT, (data: any) => {
            resolve(data);
        });
    });
    expect(data).toMatchObject({
        appName: 'web',
        bucket: {
            toggles: {
                'non-existent-toggle': {
                    yes: 0,
                    no: 1,
                    variants: { disabled: 1 },
                },
                toggle: { yes: 1, no: 0, variants: { variant: 1 } },
            },
        },
    });
    client.stop();
});

test('should send metrics when sendMetrics called', async () => {
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };

    jest.spyOn(Metrics.prototype, 'sendMetrics');

    const client = new UnleashClient(config);

    client.start();

    expect(Metrics.prototype.sendMetrics).not.toHaveBeenCalled();

    await client.sendMetrics();

    expect(Metrics.prototype.sendMetrics).toHaveBeenCalled();
});

test('Should emit RECOVERED event when sdkStatus is error and status is less than 400', (done) => {
    const data = { status: 200 }; // replace with the actual data you want to test
    fetchMock.mockResponseOnce(JSON.stringify(data), { status: 200 });

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };

    const client = new UnleashClient(config);

    client.start();

    client.on(EVENTS.INIT, () => {
        // Set error after the SDK has moved through the sdk states internally
        // eslint-disable-next-line
        // @ts-ignore - Private method by design, but we want to access it in tests
        client.sdkState = 'error';
    });

    client.on(EVENTS.RECOVERED, () => {
        // eslint-disable-next-line
        // @ts-ignore - Private method by design. but we want to access it in tests
        expect(client.sdkState).toBe('healthy');
        client.stop();
        done();
    });
});

test('Should set sdkState to healthy when client is started', (done) => {
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
    };

    const client = new UnleashClient(config);
    // eslint-disable-next-line
    // @ts-ignore - Private method by design, but we want to access it in tests
    expect(client.sdkState).toBe('initializing');

    client.start();

    client.on(EVENTS.INIT, () => {
        // eslint-disable-next-line
        // @ts-ignore - Private method by design, but we want to access it in tests
        expect(client.sdkState).toBe('healthy');
        client.stop();
        done();
    });
});

describe('READY event emission', () => {
    let client: UnleashClient;

    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap: [
            {
                enabled: false,
                name: 'test-frontend',
                variant: { name: 'some-variant', enabled: false },
                impressionData: false,
            },
        ],
        bootstrapOverride: false,
        fetch: async () => {
            return {
                ok: true,
                headers: new Map(),
                async json() {
                    return {};
                },
            };
        },
    };

    beforeEach(() => {
        fetchMock.resetMocks();
        client = new UnleashClient(config);
        jest.spyOn(client, 'emit');
    });

    test('should emit READY when response is OK and not 304, and conditions are met', async () => {
        // Mock a successful fetch response that is not 304
        fetchMock.mockResponseOnce(
            JSON.stringify({
                toggles: [{ feature: 'test-feature', enabled: true }],
            }),
            {
                status: 200,
                headers: { ETag: 'new-etag' },
            }
        );

        expect(client.emit).toHaveBeenCalledWith(EVENTS.READY);
    });
});

test('should be in ready state if bootstrapping', (done) => {
    const config: IConfig = {
        url: 'http://localhost/test',
        clientKey: '12',
        appName: 'web',
        bootstrap: [
            {
                enabled: false,
                name: 'test-frontend',
                variant: { name: 'some-variant', enabled: false },
                impressionData: false,
            },
        ],
        fetch: async () => {},
    };

    const client = new UnleashClient(config);

    client.on(EVENTS.READY, () => {
        expect(client.isReady()).toBe(true);
        client.stop();
        done();
    });
});

describe('Experimental options togglesStorageTTL disabled', () => {
    let storageProvider: IStorageProvider;
    let saveSpy: jest.SpyInstance;

    class Store implements IStorageProvider {
        public async save() {
            return Promise.resolve();
        }

        public async get() {
            return Promise.resolve([]);
        }
    }

    beforeEach(() => {
        storageProvider = new Store();
        saveSpy = jest.spyOn(storageProvider, 'save');
        jest.clearAllMocks();
    });

    test('Should not store last update flag when fetch is successful', async () => {
        fetchMock.mockResponseOnce(JSON.stringify(data));

        const config: IConfig = {
            url: 'http://localhost/test',
            clientKey: '12',
            appName: 'web',
            storageProvider,
            experimental: {},
        };

        const client = new UnleashClient(config);
        await client.start();
        expect(fetchMock).toHaveBeenCalledTimes(1);
        expect(saveSpy).not.toHaveBeenCalledWith(
            lastUpdateKey,
            expect.anything()
        );
    });

    test('Should not store last update flag even when bootstrap is set', async () => {
        localStorage.clear();
        const bootstrap = [
            {
                name: 'toggles',
                enabled: true,
                variant: {
                    name: 'disabled',
                    enabled: false,
                    feature_enabled: true,
                },
                impressionData: true,
            },
        ];

        const config: IConfig = {
            url: 'http://localhost/test',
            clientKey: '12',
            appName: 'web',
            bootstrap,
            storageProvider,
        };
        const client = new UnleashClient(config);
        await client.start();
        expect(saveSpy).not.toHaveBeenCalledWith(
            lastUpdateKey,
            expect.anything()
        );
    });
});

describe('Experimental options togglesStorageTTL enabled', () => {
    let storage: IStorageProvider;
    let fakeNow: number;

    describe('Handling last update flag storage', () => {
        let storageProvider: IStorageProvider;
        let saveSpy: jest.SpyInstance;

        class Store implements IStorageProvider {
            public async save() {
                return Promise.resolve();
            }

            public async get() {
                return Promise.resolve([]);
            }
        }

        beforeEach(() => {
            storageProvider = new Store();
            saveSpy = jest.spyOn(storageProvider, 'save');
            jest.clearAllMocks();
        });

        test('Should store last update flag when fetch is successful', async () => {
            const startTime = Date.now();
            fetchMock.mockResponseOnce(JSON.stringify(data));

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };

            const client = new UnleashClient(config);
            await client.start();
            expect(saveSpy).toHaveBeenCalledWith(lastUpdateKey, {
                key: expect.any(String),
                timestamp: expect.any(Number),
            });
            expect(
                saveSpy.mock.lastCall?.at(1).timestamp
            ).toBeGreaterThanOrEqual(startTime);
        });

        test('Should store last update flag when fetch is successful with 304 status', async () => {
            const startTime = Date.now();
            fetchMock.mockResponseOnce(JSON.stringify(data), { status: 304 });

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };

            const client = new UnleashClient(config);
            await client.start();
            expect(saveSpy).toHaveBeenCalledWith(lastUpdateKey, {
                key: expect.any(String),
                timestamp: expect.any(Number),
            });
            expect(
                saveSpy.mock.lastCall?.at(1).timestamp
            ).toBeGreaterThanOrEqual(startTime);
        });

        test('Should not store last update flag when fetch is not successful', async () => {
            fetchMock.mockResponseOnce('', { status: 500 });

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };

            const client = new UnleashClient(config);
            await client.start();
            expect(saveSpy).not.toHaveBeenCalledWith(
                lastUpdateKey,
                expect.any(Number)
            );
        });
    });

    describe('Handling last update flag storage hash value', () => {
        let storageProvider: IStorageProvider;
        let saveSpy: jest.SpyInstance;

        class Store implements IStorageProvider {
            public async save() {
                return Promise.resolve();
            }

            public async get() {
                return Promise.resolve([]);
            }
        }

        beforeEach(() => {
            storageProvider = new Store();
            saveSpy = jest.spyOn(storageProvider, 'save');
            jest.clearAllMocks();
        });

        test('Hash value computed should not change when the context value not change', async () => {
            fetchMock.mockResponse(JSON.stringify({}));

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);
            await client.start();

            const firstHash = saveSpy.mock.lastCall?.at(1).key;
            await client.updateContext({});

            const secondHash = saveSpy.mock.lastCall?.at(1).key;

            expect(firstHash).not.toBeUndefined();
            expect(secondHash).not.toBeUndefined();
            expect(firstHash).toEqual(secondHash);
        });

        test('Hash value computed should change when context value change', async () => {
            fetchMock.mockResponse(JSON.stringify({}));

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);
            await client.start();

            const firstHash = saveSpy.mock.lastCall?.at(1).key;

            await client.updateContext({ userId: '123' });

            const secondHash = saveSpy.mock.lastCall?.at(1).key;

            expect(firstHash).not.toBeUndefined();
            expect(secondHash).not.toBeUndefined();
            expect(firstHash).not.toEqual(secondHash);
        });
    });

    describe('During bootstrap initialisation', () => {
        beforeEach(async () => {
            storage = new InMemoryStorageProvider();
            jest.clearAllMocks();
        });

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

        test('Should store last update flag when bootstrap is set', async () => {
            expect.assertions(1);
            const bootstrap = [
                {
                    name: 'toggles',
                    enabled: true,
                    variant: {
                        name: 'disabled',
                        enabled: false,
                        feature_enabled: true,
                    },
                    impressionData: true,
                },
            ];

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                bootstrap,
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);

            client.on(EVENTS.READY, async () => {
                expect(await storage.get(lastUpdateKey)).not.toBeUndefined();
            });
        });

        test('Should not store last update flag when bootstrap is not set', async () => {
            expect.assertions(1);
            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);
            client.on(EVENTS.INIT, async () => {
                expect(await storage.get(lastUpdateKey)).toBeUndefined();
            });
        });
    });

    describe('With a previous storage initialisation', () => {
        beforeEach(async () => {
            fakeNow = new Date('2024-01-01').getTime();
            jest.useFakeTimers();
            jest.setSystemTime(fakeNow);
            storage = new InMemoryStorageProvider();

            fetchMock.mockResponseOnce(JSON.stringify(data)).mockResponseOnce(
                JSON.stringify({
                    toggles: [
                        {
                            name: 'simpleToggle',
                            enabled: false,
                            impressionData: true,
                        },
                    ],
                })
            );

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            // performing an initial fetch to populate the toggles and lastUpdate timestamp
            const client = new UnleashClient(config);
            await client.start();
            client.stop();

            expect(fetchMock).toHaveBeenCalledTimes(1);
            fetchMock.mockClear();
        });

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

        test('Should not perform an initial fetch when toggles are up to date', async () => {
            jest.setSystemTime(fakeNow + 59000);
            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);
            await client.start();
            const isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(true);
            client.stop();
            expect(fetchMock).toHaveBeenCalledTimes(0);
        });

        test('Should perform an initial fetch when toggles are expired', async () => {
            jest.setSystemTime(fakeNow + 61000);

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);
            await client.start();
            const isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(false);
            client.stop();
            expect(fetchMock).toHaveBeenCalledTimes(1);
        });

        test('Should perform an initial fetch when system time goes back into the past', async () => {
            jest.setSystemTime(fakeNow - 1000);

            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);
            await client.start();
            const isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(false);
            client.stop();
            expect(fetchMock).toHaveBeenCalledTimes(1);
        });

        test('Should perform an initial fetch when context has changed, even if flags are up to date', async () => {
            jest.setSystemTime(fakeNow + 59000);
            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
                context: {
                    properties: {
                        newProperty: 'newProperty',
                    },
                },
            };
            const client = new UnleashClient(config);
            await client.start();
            const isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(false);
            client.stop();
            expect(fetchMock).toHaveBeenCalledTimes(1);
        });

        test('Should send ready event when toggles are up to date', async () => {
            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);

            const readySpy = jest.fn();
            client.on(EVENTS.READY, readySpy);
            client.on(EVENTS.INIT, () => readySpy.mockClear());
            await client.start();
            expect(readySpy).toHaveBeenCalledTimes(1);
        });

        test('Should perform a fetch when context is updated, even if flags are up to date', async () => {
            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
            };
            const client = new UnleashClient(config);
            await client.start();
            let isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(true);
            await client.updateContext({ userId: '123' });
            expect(fetchMock).toHaveBeenCalledTimes(1);
            isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(false);
        });

        test('Should perform a fetch when context is updated and refreshInterval disabled, even if flags are up to date', async () => {
            const config: IConfig = {
                url: 'http://localhost/test',
                clientKey: '12',
                appName: 'web',
                storageProvider: storage,
                experimental: {
                    togglesStorageTTL: 60,
                },
                refreshInterval: 0,
            };
            const client = new UnleashClient(config);
            await client.start();
            let isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(true);
            await client.updateContext({ userId: '123' });
            expect(fetchMock).toHaveBeenCalledTimes(1);
            isEnabled = client.isEnabled('simpleToggle');
            expect(isEnabled).toBe(false);
        });
    });
});

describe('updateToggles', () => {
    it('should not update toggles when not started', () => {
        const config: IConfig = {
            url: 'http://localhost/test',
            clientKey: '12',
            appName: 'web',
        };
        const client = new UnleashClient(config);

        client.updateToggles();

        expect(fetchMock).not.toHaveBeenCalled();
    });

    it('should update toggles when started', async () => {
        const config: IConfig = {
            url: 'http://localhost/test',
            clientKey: '12',
            appName: 'web',
        };
        const client = new UnleashClient(config);

        await client.start();
        fetchMock.mockClear();

        client.updateToggles();

        expect(fetchMock).toHaveBeenCalled();
    });

    it('should wait for client readiness before the toggles update', async () => {
        const config: IConfig = {
            url: 'http://localhost/test',
            clientKey: '12',
            appName: 'web',
            refreshInterval: 0,
        };
        const client = new UnleashClient(config);

        client.start();

        client.updateToggles();

        expect(fetchMock).not.toHaveBeenCalled();

        client.emit(EVENTS.READY);

        expect(fetchMock).toHaveBeenCalledTimes(1);
    });
});