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Diffstat (limited to 'remote/test/puppeteer/src/common/ExecutionContext.ts')
-rw-r--r-- | remote/test/puppeteer/src/common/ExecutionContext.ts | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/remote/test/puppeteer/src/common/ExecutionContext.ts b/remote/test/puppeteer/src/common/ExecutionContext.ts new file mode 100644 index 0000000000..4420410de0 --- /dev/null +++ b/remote/test/puppeteer/src/common/ExecutionContext.ts @@ -0,0 +1,387 @@ +/** + * Copyright 2017 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. + */ + +import { assert } from './assert.js'; +import { helper } from './helper.js'; +import { createJSHandle, JSHandle, ElementHandle } from './JSHandle.js'; +import { CDPSession } from './Connection.js'; +import { DOMWorld } from './DOMWorld.js'; +import { Frame } from './FrameManager.js'; +import { Protocol } from 'devtools-protocol'; +import { EvaluateHandleFn, SerializableOrJSHandle } from './EvalTypes.js'; + +export const EVALUATION_SCRIPT_URL = '__puppeteer_evaluation_script__'; +const SOURCE_URL_REGEX = /^[\040\t]*\/\/[@#] sourceURL=\s*(\S*?)\s*$/m; + +/** + * This class represents a context for JavaScript execution. A [Page] might have + * many execution contexts: + * - each + * {@link https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe | + * frame } has "default" execution context that is always created after frame is + * attached to DOM. This context is returned by the + * {@link frame.executionContext()} method. + * - {@link https://developer.chrome.com/extensions | Extension}'s content scripts + * create additional execution contexts. + * + * Besides pages, execution contexts can be found in + * {@link https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API | + * workers }. + * + * @public + */ +export class ExecutionContext { + /** + * @internal + */ + _client: CDPSession; + /** + * @internal + */ + _world: DOMWorld; + /** + * @internal + */ + _contextId: number; + + /** + * @internal + */ + constructor( + client: CDPSession, + contextPayload: Protocol.Runtime.ExecutionContextDescription, + world: DOMWorld + ) { + this._client = client; + this._world = world; + this._contextId = contextPayload.id; + } + + /** + * @remarks + * + * Not every execution context is associated with a frame. For + * example, workers and extensions have execution contexts that are not + * associated with frames. + * + * @returns The frame associated with this execution context. + */ + frame(): Frame | null { + return this._world ? this._world.frame() : null; + } + + /** + * @remarks + * If the function passed to the `executionContext.evaluate` returns a + * Promise, then `executionContext.evaluate` would wait for the promise to + * resolve and return its value. If the function passed to the + * `executionContext.evaluate` returns a non-serializable value, then + * `executionContext.evaluate` resolves to `undefined`. DevTools Protocol also + * supports transferring some additional values that are not serializable by + * `JSON`: `-0`, `NaN`, `Infinity`, `-Infinity`, and bigint literals. + * + * + * @example + * ```js + * const executionContext = await page.mainFrame().executionContext(); + * const result = await executionContext.evaluate(() => Promise.resolve(8 * 7))* ; + * console.log(result); // prints "56" + * ``` + * + * @example + * A string can also be passed in instead of a function. + * + * ```js + * console.log(await executionContext.evaluate('1 + 2')); // prints "3" + * ``` + * + * @example + * {@link JSHandle} instances can be passed as arguments to the + * `executionContext.* evaluate`: + * ```js + * const oneHandle = await executionContext.evaluateHandle(() => 1); + * const twoHandle = await executionContext.evaluateHandle(() => 2); + * const result = await executionContext.evaluate( + * (a, b) => a + b, oneHandle, * twoHandle + * ); + * await oneHandle.dispose(); + * await twoHandle.dispose(); + * console.log(result); // prints '3'. + * ``` + * @param pageFunction a function to be evaluated in the `executionContext` + * @param args argument to pass to the page function + * + * @returns A promise that resolves to the return value of the given function. + */ + async evaluate<ReturnType extends any>( + pageFunction: Function | string, + ...args: unknown[] + ): Promise<ReturnType> { + return await this._evaluateInternal<ReturnType>( + true, + pageFunction, + ...args + ); + } + + /** + * @remarks + * The only difference between `executionContext.evaluate` and + * `executionContext.evaluateHandle` is that `executionContext.evaluateHandle` + * returns an in-page object (a {@link JSHandle}). + * If the function passed to the `executionContext.evaluateHandle` returns a + * Promise, then `executionContext.evaluateHandle` would wait for the + * promise to resolve and return its value. + * + * @example + * ```js + * const context = await page.mainFrame().executionContext(); + * const aHandle = await context.evaluateHandle(() => Promise.resolve(self)); + * aHandle; // Handle for the global object. + * ``` + * + * @example + * A string can also be passed in instead of a function. + * + * ```js + * // Handle for the '3' * object. + * const aHandle = await context.evaluateHandle('1 + 2'); + * ``` + * + * @example + * JSHandle instances can be passed as arguments + * to the `executionContext.* evaluateHandle`: + * + * ```js + * const aHandle = await context.evaluateHandle(() => document.body); + * const resultHandle = await context.evaluateHandle(body => body.innerHTML, * aHandle); + * console.log(await resultHandle.jsonValue()); // prints body's innerHTML + * await aHandle.dispose(); + * await resultHandle.dispose(); + * ``` + * + * @param pageFunction a function to be evaluated in the `executionContext` + * @param args argument to pass to the page function + * + * @returns A promise that resolves to the return value of the given function + * as an in-page object (a {@link JSHandle}). + */ + async evaluateHandle<HandleType extends JSHandle | ElementHandle = JSHandle>( + pageFunction: EvaluateHandleFn, + ...args: SerializableOrJSHandle[] + ): Promise<HandleType> { + return this._evaluateInternal<HandleType>(false, pageFunction, ...args); + } + + private async _evaluateInternal<ReturnType>( + returnByValue: boolean, + pageFunction: Function | string, + ...args: unknown[] + ): Promise<ReturnType> { + const suffix = `//# sourceURL=${EVALUATION_SCRIPT_URL}`; + + if (helper.isString(pageFunction)) { + const contextId = this._contextId; + const expression = pageFunction; + const expressionWithSourceUrl = SOURCE_URL_REGEX.test(expression) + ? expression + : expression + '\n' + suffix; + + const { exceptionDetails, result: remoteObject } = await this._client + .send('Runtime.evaluate', { + expression: expressionWithSourceUrl, + contextId, + returnByValue, + awaitPromise: true, + userGesture: true, + }) + .catch(rewriteError); + + if (exceptionDetails) + throw new Error( + 'Evaluation failed: ' + helper.getExceptionMessage(exceptionDetails) + ); + + return returnByValue + ? helper.valueFromRemoteObject(remoteObject) + : createJSHandle(this, remoteObject); + } + + if (typeof pageFunction !== 'function') + throw new Error( + `Expected to get |string| or |function| as the first argument, but got "${pageFunction}" instead.` + ); + + let functionText = pageFunction.toString(); + try { + new Function('(' + functionText + ')'); + } catch (error) { + // This means we might have a function shorthand. Try another + // time prefixing 'function '. + if (functionText.startsWith('async ')) + functionText = + 'async function ' + functionText.substring('async '.length); + else functionText = 'function ' + functionText; + try { + new Function('(' + functionText + ')'); + } catch (error) { + // We tried hard to serialize, but there's a weird beast here. + throw new Error('Passed function is not well-serializable!'); + } + } + let callFunctionOnPromise; + try { + callFunctionOnPromise = this._client.send('Runtime.callFunctionOn', { + functionDeclaration: functionText + '\n' + suffix + '\n', + executionContextId: this._contextId, + arguments: args.map(convertArgument.bind(this)), + returnByValue, + awaitPromise: true, + userGesture: true, + }); + } catch (error) { + if ( + error instanceof TypeError && + error.message.startsWith('Converting circular structure to JSON') + ) + error.message += ' Are you passing a nested JSHandle?'; + throw error; + } + const { + exceptionDetails, + result: remoteObject, + } = await callFunctionOnPromise.catch(rewriteError); + if (exceptionDetails) + throw new Error( + 'Evaluation failed: ' + helper.getExceptionMessage(exceptionDetails) + ); + return returnByValue + ? helper.valueFromRemoteObject(remoteObject) + : createJSHandle(this, remoteObject); + + /** + * @param {*} arg + * @returns {*} + * @this {ExecutionContext} + */ + function convertArgument(this: ExecutionContext, arg: unknown): unknown { + if (typeof arg === 'bigint') + // eslint-disable-line valid-typeof + return { unserializableValue: `${arg.toString()}n` }; + if (Object.is(arg, -0)) return { unserializableValue: '-0' }; + if (Object.is(arg, Infinity)) return { unserializableValue: 'Infinity' }; + if (Object.is(arg, -Infinity)) + return { unserializableValue: '-Infinity' }; + if (Object.is(arg, NaN)) return { unserializableValue: 'NaN' }; + const objectHandle = arg && arg instanceof JSHandle ? arg : null; + if (objectHandle) { + if (objectHandle._context !== this) + throw new Error( + 'JSHandles can be evaluated only in the context they were created!' + ); + if (objectHandle._disposed) throw new Error('JSHandle is disposed!'); + if (objectHandle._remoteObject.unserializableValue) + return { + unserializableValue: objectHandle._remoteObject.unserializableValue, + }; + if (!objectHandle._remoteObject.objectId) + return { value: objectHandle._remoteObject.value }; + return { objectId: objectHandle._remoteObject.objectId }; + } + return { value: arg }; + } + + function rewriteError(error: Error): Protocol.Runtime.EvaluateResponse { + if (error.message.includes('Object reference chain is too long')) + return { result: { type: 'undefined' } }; + if (error.message.includes("Object couldn't be returned by value")) + return { result: { type: 'undefined' } }; + + if ( + error.message.endsWith('Cannot find context with specified id') || + error.message.endsWith('Inspected target navigated or closed') + ) + throw new Error( + 'Execution context was destroyed, most likely because of a navigation.' + ); + throw error; + } + } + + /** + * This method iterates the JavaScript heap and finds all the objects with the + * given prototype. + * @remarks + * @example + * ```js + * // Create a Map object + * await page.evaluate(() => window.map = new Map()); + * // Get a handle to the Map object prototype + * const mapPrototype = await page.evaluateHandle(() => Map.prototype); + * // Query all map instances into an array + * const mapInstances = await page.queryObjects(mapPrototype); + * // Count amount of map objects in heap + * const count = await page.evaluate(maps => maps.length, mapInstances); + * await mapInstances.dispose(); + * await mapPrototype.dispose(); + * ``` + * + * @param prototypeHandle a handle to the object prototype + * + * @returns A handle to an array of objects with the given prototype. + */ + async queryObjects(prototypeHandle: JSHandle): Promise<JSHandle> { + assert(!prototypeHandle._disposed, 'Prototype JSHandle is disposed!'); + assert( + prototypeHandle._remoteObject.objectId, + 'Prototype JSHandle must not be referencing primitive value' + ); + const response = await this._client.send('Runtime.queryObjects', { + prototypeObjectId: prototypeHandle._remoteObject.objectId, + }); + return createJSHandle(this, response.objects); + } + + /** + * @internal + */ + async _adoptBackendNodeId( + backendNodeId: Protocol.DOM.BackendNodeId + ): Promise<ElementHandle> { + const { object } = await this._client.send('DOM.resolveNode', { + backendNodeId: backendNodeId, + executionContextId: this._contextId, + }); + return createJSHandle(this, object) as ElementHandle; + } + + /** + * @internal + */ + async _adoptElementHandle( + elementHandle: ElementHandle + ): Promise<ElementHandle> { + assert( + elementHandle.executionContext() !== this, + 'Cannot adopt handle that already belongs to this execution context' + ); + assert(this._world, 'Cannot adopt handle without DOMWorld'); + const nodeInfo = await this._client.send('DOM.describeNode', { + objectId: elementHandle._remoteObject.objectId, + }); + return this._adoptBackendNodeId(nodeInfo.node.backendNodeId); + } +} |