sentry/static/app/__mocks__/api.tsx

import isEqual from 'lodash/isEqual';

import type * as ApiNamespace from 'sentry/api';

const RealApi: typeof ApiNamespace = jest.requireActual('sentry/api');

export const initApiClientErrorHandling = RealApi.initApiClientErrorHandling;
export const hasProjectBeenRenamed = RealApi.hasProjectBeenRenamed;

const respond = (
  asyncDelay: AsyncDelay,
  fn: FunctionCallback | undefined,
  ...args: any[]
): void => {
  if (!fn) {
    return;
  }

  if (asyncDelay !== undefined) {
    setTimeout(() => fn(...args), asyncDelay);
    return;
  }

  fn(...args);
};

type FunctionCallback<Args extends any[] = any[]> = (...args: Args) => void;

/**
 * Callables for matching requests based on arbitrary conditions.
 */
type MatchCallable = (url: string, options: ApiNamespace.RequestOptions) => boolean;

type AsyncDelay = undefined | number;
interface ResponseType extends ApiNamespace.ResponseMeta {
  body: any;
  callCount: 0;
  headers: Record<string, string>;
  host: string;
  match: MatchCallable[];
  method: string;
  statusCode: number;
  url: string;
  /**
   * Whether to return mocked api responses directly, or with a setTimeout delay.
   *
   * Set to `null` to disable the async delay
   * Set to a `number` which will be the amount of time (ms) for the delay
   *
   * This will override `MockApiClient.asyncDelay` for this request.
   */
  asyncDelay?: AsyncDelay;
  query?: Record<string, string | number | boolean | string[] | number[]>;
}

type MockResponse = [resp: ResponseType, mock: jest.Mock];

/**
 * Compare two records. `want` is all the entries we want to have the same value in `check`
 */
function compareRecord(want: Record<string, any>, check: Record<string, any>): boolean {
  for (const entry of Object.entries(want)) {
    const [key, value] = entry;
    if (!isEqual(check[key], value)) {
      return false;
    }
  }
  return true;
}

afterEach(() => {
  // if any errors are caught we console.error them
  const errors = Object.values(Client.errors);
  if (errors.length > 0) {
    for (const err of errors) {
      // eslint-disable-next-line no-console
      console.error(err);
    }
    Client.errors = {};
  }

  // Mock responses are removed between tests
  Client.clearMockResponses();
});

class Client implements ApiNamespace.Client {
  activeRequests: Record<string, ApiNamespace.Request> = {};
  baseUrl = '';
  // uses the default client json headers. Sadly, we cannot refernce the real client
  // because it will cause a circular dependency and explode, hence the copy/paste
  headers = {
    Accept: 'application/json; charset=utf-8',
    'Content-Type': 'application/json',
  };

  static mockResponses: MockResponse[] = [];

  /**
   * Whether to return mocked api responses directly, or with a setTimeout delay.
   *
   * Set to `null` to disable the async delay
   * Set to a `number` which will be the amount of time (ms) for the delay
   *
   * This is the global/default value. `addMockResponse` can override per request.
   */
  static asyncDelay: AsyncDelay = undefined;

  static clearMockResponses() {
    Client.mockResponses = [];
  }

  /**
   * Create a query string match callable.
   *
   * Only keys/values defined in `query` are checked.
   */
  static matchQuery(query: Record<string, any>): MatchCallable {
    const queryMatcher: MatchCallable = (_url, options) => {
      return compareRecord(query, options.query ?? {});
    };

    return queryMatcher;
  }

  /**
   * Create a data match callable.
   *
   * Only keys/values defined in `data` are checked.
   */
  static matchData(data: Record<string, any>): MatchCallable {
    const dataMatcher: MatchCallable = (_url, options) => {
      return compareRecord(data, options.data ?? {});
    };

    return dataMatcher;
  }

  // Returns a jest mock that represents Client.request calls
  static addMockResponse(response: Partial<ResponseType>) {
    const mock = jest.fn();

    Client.mockResponses.unshift([
      {
        host: '',
        url: '',
        status: 200,
        statusCode: 200,
        statusText: 'OK',
        responseText: '',
        responseJSON: '',
        body: '',
        method: 'GET',
        callCount: 0,
        match: [],
        ...response,
        asyncDelay: response.asyncDelay ?? Client.asyncDelay,
        headers: response.headers ?? {},
        getResponseHeader: (key: string) => response.headers?.[key] ?? null,
      },
      mock,
    ]);

    return mock;
  }

  static findMockResponse(url: string, options: Readonly<ApiNamespace.RequestOptions>) {
    return Client.mockResponses.find(([response]) => {
      if (response.host && (options.host || '') !== response.host) {
        return false;
      }
      if (url !== response.url) {
        return false;
      }
      if ((options.method || 'GET') !== response.method) {
        return false;
      }
      return response.match.every(matcher => matcher(url, options));
    });
  }

  uniqueId() {
    return '123';
  }

  /**
   * In the real client, this clears in-flight responses. It's NOT
   * clearMockResponses. You probably don't want to call this from a test.
   */
  clear() {
    Object.values(this.activeRequests).forEach(r => r.cancel());
  }

  wrapCallback<T extends any[]>(
    _id: string,
    func: FunctionCallback<T> | undefined,
    _cleanup = false
  ) {
    const asyncDelay = Client.asyncDelay;

    return (...args: T) => {
      if ((RealApi.hasProjectBeenRenamed as any)(...args)) {
        return;
      }
      respond(asyncDelay, func, ...args);
    };
  }

  requestPromise(
    path: string,
    {
      includeAllArgs,
      ...options
    }: {includeAllArgs?: boolean} & Readonly<ApiNamespace.RequestOptions> = {}
  ): any {
    return new Promise((resolve, reject) => {
      this.request(path, {
        ...options,
        success: (data, ...args) => {
          resolve(includeAllArgs ? [data, ...args] : data);
        },
        error: (error, ..._args) => {
          reject(error);
        },
      });
    });
  }

  static errors: Record<string, Error> = {};

  // XXX(ts): We type the return type for requestPromise and request as `any`. Typically these woul
  request(url: string, options: Readonly<ApiNamespace.RequestOptions> = {}): any {
    const [response, mock] = Client.findMockResponse(url, options) || [
      undefined,
      undefined,
    ];
    if (!response || !mock) {
      const methodAndUrl = `${options.method || 'GET'} ${url}`;
      // Endpoints need to be mocked
      const err = new Error(`No mocked response found for request: ${methodAndUrl}`);

      // Mutate stack to drop frames since test file so that we know where in the test
      // this needs to be mocked
      const lines = err.stack?.split('\n');
      const startIndex = lines?.findIndex(line => line.includes('.spec.'));
      err.stack = ['\n', lines?.[0], ...(lines?.slice(startIndex) ?? [])].join('\n');

      // Throwing an error here does not do what we want it to do....
      // Because we are mocking an API client, we generally catch errors to show
      // user-friendly error messages, this means in tests this error gets gobbled
      // up and developer frustration ensues.
      // We track the errors on a static member and warn afterEach test.
      Client.errors[methodAndUrl] = err;
    } else {
      // has mocked response

      // mock gets returned when we add a mock response, will represent calls to api.request
      mock(url, options);

      const body =
        typeof response.body === 'function' ? response.body(url, options) : response.body;

      if (response.statusCode >= 300) {
        response.callCount++;

        const errorResponse = Object.assign(
          {
            status: response.statusCode,
            responseText: JSON.stringify(body),
            responseJSON: body,
          },
          {
            overrideMimeType: () => {},
            abort: () => {},
            then: () => {},
            error: () => {},
          },
          new XMLHttpRequest()
        );

        this.handleRequestError(
          {
            id: '1234',
            path: url,
            requestOptions: options,
          },
          errorResponse as any,
          'error',
          'error'
        );
      } else {
        response.callCount++;
        respond(
          response.asyncDelay,
          options.success,
          body,
          {},
          {
            getResponseHeader: (key: string) => response.headers[key],
            statusCode: response.statusCode,
            status: response.statusCode,
          }
        );
      }
    }

    respond(response?.asyncDelay, options.complete);
  }

  handleRequestError = RealApi.Client.prototype.handleRequestError;
}

export {Client};