puppeteer-core
Version:
A high-level API to control headless Chrome over the DevTools Protocol
284 lines • 11.1 kB
JavaScript
/**
* 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.
*/
var __classPrivateFieldGet = (this && this.__classPrivateFieldGet) || function (receiver, state, kind, f) {
if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
};
var _ExecutionContext_instances, _ExecutionContext_evaluate;
import { JSHandle } from './JSHandle.js';
import { LazyArg } from './LazyArg.js';
import { createJSHandle, getExceptionMessage, isString, valueFromRemoteObject, } from './util.js';
/**
* @public
*/
export const EVALUATION_SCRIPT_URL = 'pptr://__puppeteer_evaluation_script__';
const SOURCE_URL_REGEX = /^[\040\t]*\/\/[@#] sourceURL=\s*(\S*?)\s*$/m;
/**
* Represents a context for JavaScript execution.
*
* @example
* A {@link Page} can have several execution contexts:
*
* - Each {@link Frame} of a {@link Page | page} has a "default" execution
* context that is always created after frame is attached to DOM. This context
* is returned by the {@link Frame.executionContext} method.
* - Each {@link https://developer.chrome.com/extensions | Chrome extensions}
* creates additional execution contexts to isolate their code.
*
* @remarks
* By definition, each context is isolated from one another, however they are
* all able to manipulate non-JavaScript resources (such as DOM).
*
* @remarks
* Besides pages, execution contexts can be found in
* {@link WebWorker | workers}.
*
* @internal
*/
export class ExecutionContext {
/**
* @internal
*/
constructor(client, contextPayload, world) {
_ExecutionContext_instances.add(this);
this._client = client;
this._world = world;
this._contextId = contextPayload.id;
this._contextName = contextPayload.name;
}
/**
* Evaluates the given function.
*
* @example
*
* ```ts
* 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:
*
* ```ts
* console.log(await executionContext.evaluate('1 + 2')); // prints "3"
* ```
*
* @example
* Handles can also be passed as `args`. They resolve to their referenced object:
*
* ```ts
* 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 - The function to evaluate.
* @param args - Additional arguments to pass into the function.
* @returns The result of evaluating the function. If the result is an object,
* a vanilla object containing the serializable properties of the result is
* returned.
*/
async evaluate(pageFunction, ...args) {
return await __classPrivateFieldGet(this, _ExecutionContext_instances, "m", _ExecutionContext_evaluate).call(this, true, pageFunction, ...args);
}
/**
* Evaluates the given function.
*
* Unlike {@link ExecutionContext.evaluate | evaluate}, this method returns a
* handle to the result of the function.
*
* This method may be better suited if the object cannot be serialized (e.g.
* `Map`) and requires further manipulation.
*
* @example
*
* ```ts
* const context = await page.mainFrame().executionContext();
* const handle: JSHandle<typeof globalThis> = await context.evaluateHandle(
* () => Promise.resolve(self)
* );
* ```
*
* @example
* A string can also be passed in instead of a function.
*
* ```ts
* const handle: JSHandle<number> = await context.evaluateHandle('1 + 2');
* ```
*
* @example
* Handles can also be passed as `args`. They resolve to their referenced object:
*
* ```ts
* const bodyHandle: ElementHandle<HTMLBodyElement> =
* await context.evaluateHandle(() => {
* return document.body;
* });
* const stringHandle: JSHandle<string> = await context.evaluateHandle(
* body => body.innerHTML,
* body
* );
* console.log(await stringHandle.jsonValue()); // prints body's innerHTML
* // Always dispose your garbage! :)
* await bodyHandle.dispose();
* await stringHandle.dispose();
* ```
*
* @param pageFunction - The function to evaluate.
* @param args - Additional arguments to pass into the function.
* @returns A {@link JSHandle | handle} to the result of evaluating the
* function. If the result is a `Node`, then this will return an
* {@link ElementHandle | element handle}.
*/
async evaluateHandle(pageFunction, ...args) {
return __classPrivateFieldGet(this, _ExecutionContext_instances, "m", _ExecutionContext_evaluate).call(this, false, pageFunction, ...args);
}
}
_ExecutionContext_instances = new WeakSet(), _ExecutionContext_evaluate = async function _ExecutionContext_evaluate(returnByValue, pageFunction, ...args) {
const suffix = `//# sourceURL=${EVALUATION_SCRIPT_URL}`;
if (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: ' + getExceptionMessage(exceptionDetails));
}
return returnByValue
? valueFromRemoteObject(remoteObject)
: createJSHandle(this, remoteObject);
}
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: await Promise.all(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 += ' Recursive objects are not allowed.';
}
throw error;
}
const { exceptionDetails, result: remoteObject } = await callFunctionOnPromise.catch(rewriteError);
if (exceptionDetails) {
throw new Error('Evaluation failed: ' + getExceptionMessage(exceptionDetails));
}
return returnByValue
? valueFromRemoteObject(remoteObject)
: createJSHandle(this, remoteObject);
async function convertArgument(arg) {
if (arg instanceof LazyArg) {
arg = await arg.get();
}
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.executionContext() !== 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 };
}
};
const rewriteError = (error) => {
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;
};
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