playwright/test/apicoverage.spec.js

/**
 * Copyright 2017 Google Inc. All rights reserved.
 * Modifications copyright (c) Microsoft Corporation.
 *
 * 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.
 */

/**
 * @param {Map<string, boolean>} apiCoverage
 * @param {Object} events
 * @param {string} className
 * @param {!Object} classType
 */
function traceAPICoverage(apiCoverage, events, className, classType) {
  className = className.substring(0, 1).toLowerCase() + className.substring(1);
  for (const methodName of Reflect.ownKeys(classType.prototype)) {
    const method = Reflect.get(classType.prototype, methodName);
    if (methodName === 'constructor' || typeof methodName !== 'string' || methodName.startsWith('_') || typeof method !== 'function')
      continue;
    apiCoverage.set(`${className}.${methodName}`, false);
    Reflect.set(classType.prototype, methodName, function(...args) {
      apiCoverage.set(`${className}.${methodName}`, true);
      return method.call(this, ...args);
    });
  }

  if (events[classType.name]) {
    for (const event of Object.values(events[classType.name])) {
      if (typeof event !== 'symbol')
        apiCoverage.set(`${className}.emit(${JSON.stringify(event)})`, false);
    }
    const method = Reflect.get(classType.prototype, 'emit');
    Reflect.set(classType.prototype, 'emit', function(event, ...args) {
      if (typeof event !== 'symbol' && this.listenerCount(event))
        apiCoverage.set(`${className}.emit(${JSON.stringify(event)})`, true);
      return method.call(this, event, ...args);
    });
  }
}

module.exports.describe = function({browserType}) {
  describe('**API COVERAGE**', () => {
    const BROWSER_CONFIGS = [
      {
        name: 'Firefox',
        events: require('../lib/events').Events,
        missingCoverage: ['browserContext.setGeolocation', 'browserContext.setOffline', 'cDPSession.send', 'cDPSession.detach'],
      },
      {
        name: 'WebKit',
        events: require('../lib/events').Events,
        missingCoverage: ['browserContext.clearPermissions', 'cDPSession.send', 'cDPSession.detach'],
      },
      {
        name: 'Chromium',
        events: {
          ...require('../lib/events').Events,
          ...require('../lib/chromium/events').Events,
        },
        missingCoverage: [],
      },
    ];
    const browserConfig = BROWSER_CONFIGS.find(config => config.name.toLowerCase() === browserType.name());
    const events = browserConfig.events;
    const api = require('../lib/api');

    const coverage = new Map();
    Object.keys(api).forEach(apiName => {
      if (BROWSER_CONFIGS.some(config => apiName.startsWith(config.name)) && !apiName.startsWith(browserConfig.name))
        return;
      traceAPICoverage(coverage, events, apiName, api[apiName]);
    });

    it('should call all API methods', () => {
      const ignoredMethods = new Set(browserConfig.missingCoverage);
      const missingMethods = [];
      const extraIgnoredMethods = [];
      for (const method of coverage.keys()) {
        // Sometimes we already have a background page while launching, before adding a listener.
        if (method === 'chromiumBrowserContext.emit("backgroundpage")')
          continue;
        if (!coverage.get(method) && !ignoredMethods.has(method))
          missingMethods.push(method);
        else if (coverage.get(method) && ignoredMethods.has(method))
          extraIgnoredMethods.push(method);
      }
      if (extraIgnoredMethods.length)
        throw new Error('Certain API Methods are called and should not be ignored: ' + extraIgnoredMethods.join(', '));
      if (missingMethods.length)
        throw new Error('Certain API Methods are not called: ' + missingMethods.join(', '));
    });
  });
};