puppeteer/test/coverage-utils.js
Jack Franklin e655bb6ca2
chore(agnostification): split up root Puppeteer class (#6504)
The `Puppeteer` class had two concerns:

* connect to an existing browser
* launch a new browser

The first of those concerns is needed in all environments, but the
second is only needed in Node.
https://github.com/puppeteer/puppeteer/pull/6484 landing enabled us to
pull the `Puppeteer` class apart into two:

1. `Puppeteer` which hosts the behaviour for connecting to existing
   browsers.
2. `PuppeteerNode`, which extends `Puppeteer` and also adds the ability
   to launch a new browser.

This is a non-breaking change, because Node users will still get an
instance of a class with all the methods they expect, but it'll be a
`PuppeteerNode` rather than `Puppeteer`. I don't expect this to cause
people any issues.

We also now have new files that are effectively the entry points for
Puppeteer:

* `node.ts`: the main entry point for Puppeteer on Node.
* `web.ts`: the main entry point for Puppeteer on the web.
* `node-puppeteer-core.ts`: for those using puppeteer-core (which only
  exists in Node, not on the web).
2020-10-13 16:19:26 +01:00

165 lines
5.8 KiB
JavaScript

/**
* Copyright 2020 Google Inc. All rights reserved.
*
* 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.
*/
// TODO (@jackfranklin): convert this to TypeScript and enable type-checking
// @ts-nocheck
/* We want to ensure that all of Puppeteer's public API is tested via our unit
* tests but we can't use a tool like Istanbul because the way it instruments
* code unfortunately breaks in Puppeteer where some of that code is then being
* executed in a browser context.
*
* So instead we maintain this coverage code which does the following:
* * takes every public method that we expect to be tested
* * replaces it with a method that calls the original but also updates a Map of calls
* * in an after() test callback it asserts that every public method was called.
*
* We run this when COVERAGE=1.
*/
const path = require('path');
const fs = require('fs');
/**
* This object is also used by DocLint to know which classes to check are
* documented. It's a pretty hacky solution but DocLint is going away soon as
* part of the TSDoc migration.
*/
const MODULES_TO_CHECK_FOR_COVERAGE = {
Accessibility: '../lib/cjs/puppeteer/common/Accessibility',
Browser: '../lib/cjs/puppeteer/common/Browser',
BrowserContext: '../lib/cjs/puppeteer/common/Browser',
BrowserFetcher: '../lib/cjs/puppeteer/node/BrowserFetcher',
CDPSession: '../lib/cjs/puppeteer/common/Connection',
ConsoleMessage: '../lib/cjs/puppeteer/common/ConsoleMessage',
Coverage: '../lib/cjs/puppeteer/common/Coverage',
Dialog: '../lib/cjs/puppeteer/common/Dialog',
ElementHandle: '../lib/cjs/puppeteer/common/JSHandle',
ExecutionContext: '../lib/cjs/puppeteer/common/ExecutionContext',
EventEmitter: '../lib/cjs/puppeteer/common/EventEmitter',
FileChooser: '../lib/cjs/puppeteer/common/FileChooser',
Frame: '../lib/cjs/puppeteer/common/FrameManager',
JSHandle: '../lib/cjs/puppeteer/common/JSHandle',
Keyboard: '../lib/cjs/puppeteer/common/Input',
Mouse: '../lib/cjs/puppeteer/common/Input',
Page: '../lib/cjs/puppeteer/common/Page',
Puppeteer: '../lib/cjs/puppeteer/common/Puppeteer',
PuppeteerNode: '../lib/cjs/puppeteer/node/Puppeteer',
HTTPRequest: '../lib/cjs/puppeteer/common/HTTPRequest',
HTTPResponse: '../lib/cjs/puppeteer/common/HTTPResponse',
SecurityDetails: '../lib/cjs/puppeteer/common/SecurityDetails',
Target: '../lib/cjs/puppeteer/common/Target',
TimeoutError: '../lib/cjs/puppeteer/common/Errors',
Touchscreen: '../lib/cjs/puppeteer/common/Input',
Tracing: '../lib/cjs/puppeteer/common/Tracing',
WebWorker: '../lib/cjs/puppeteer/common/WebWorker',
};
function traceAPICoverage(apiCoverage, className, modulePath) {
const loadedModule = require(modulePath);
const classType = loadedModule[className];
if (!classType || !classType.prototype) {
console.error(
`Coverage error: could not find class for ${className}. Is src/api.ts up to date?`
);
process.exit(1);
}
for (const methodName of Reflect.ownKeys(classType.prototype)) {
const method = Reflect.get(classType.prototype, methodName);
if (
methodName === 'constructor' ||
typeof methodName !== 'string' ||
methodName.startsWith('_') ||
typeof method !== 'function'
)
continue;
apiCoverage.set(`${className}.${methodName}`, false);
Reflect.set(classType.prototype, methodName, function (...args) {
apiCoverage.set(`${className}.${methodName}`, true);
return method.call(this, ...args);
});
}
/**
* If classes emit events, those events are exposed via an object in the same
* module named XEmittedEvents, where X is the name of the class. For example,
* the Page module exposes PageEmittedEvents.
*/
const eventsName = `${className}EmittedEvents`;
if (loadedModule[eventsName]) {
for (const event of Object.values(loadedModule[eventsName])) {
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);
});
}
}
const coverageLocation = path.join(__dirname, 'coverage.json');
const clearOldCoverage = () => {
try {
fs.unlinkSync(coverageLocation);
} catch (error) {
// do nothing, the file didn't exist
}
};
const writeCoverage = (coverage) => {
fs.writeFileSync(coverageLocation, JSON.stringify([...coverage.entries()]));
};
const getCoverageResults = () => {
let contents;
try {
contents = fs.readFileSync(coverageLocation, { encoding: 'utf8' });
} catch (error) {
console.error('Warning: coverage file does not exist or is not readable.');
}
const coverageMap = new Map(JSON.parse(contents));
return coverageMap;
};
const trackCoverage = () => {
clearOldCoverage();
const coverageMap = new Map();
return {
beforeAll: () => {
for (const [className, moduleFilePath] of Object.entries(
MODULES_TO_CHECK_FOR_COVERAGE
)) {
traceAPICoverage(coverageMap, className, moduleFilePath);
}
},
afterAll: () => {
writeCoverage(coverageMap);
},
};
};
module.exports = {
trackCoverage,
getCoverageResults,
MODULES_TO_CHECK_FOR_COVERAGE,
};