add hw2

node_modules/chromium-bidi/lib/cjs/bidiMapper/modules/script/ChannelProxy.js

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+"use strict";
+/*
+ * Copyright 2023 Google LLC.
+ * 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.
+ *
+ */
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.ChannelProxy = void 0;
+const protocol_js_1 = require("../../../protocol/protocol.js");
+const log_js_1 = require("../../../utils/log.js");
+const uuid_js_1 = require("../../../utils/uuid.js");
+/**
+ * Used to send messages from realm to BiDi user.
+ */
+class ChannelProxy {
+    #properties;
+    #id = (0, uuid_js_1.uuidv4)();
+    #logger;
+    constructor(channel, logger) {
+        this.#properties = channel;
+        this.#logger = logger;
+    }
+    /**
+     * Creates a channel proxy in the given realm, initialises listener and
+     * returns a handle to `sendMessage` delegate.
+     */
+    async init(realm, eventManager) {
+        const channelHandle = await ChannelProxy.#createAndGetHandleInRealm(realm);
+        const sendMessageHandle = await ChannelProxy.#createSendMessageHandle(realm, channelHandle);
+        void this.#startListener(realm, channelHandle, eventManager);
+        return sendMessageHandle;
+    }
+    /** Gets a ChannelProxy from window and returns its handle. */
+    async startListenerFromWindow(realm, eventManager) {
+        try {
+            const channelHandle = await this.#getHandleFromWindow(realm);
+            void this.#startListener(realm, channelHandle, eventManager);
+        }
+        catch (error) {
+            this.#logger?.(log_js_1.LogType.debugError, error);
+        }
+    }
+    /**
+     * Evaluation string which creates a ChannelProxy object on the client side.
+     */
+    static #createChannelProxyEvalStr() {
+        const functionStr = String(() => {
+            const queue = [];
+            let queueNonEmptyResolver = null;
+            return {
+                /**
+                 * Gets a promise, which is resolved as soon as a message occurs
+                 * in the queue.
+                 */
+                async getMessage() {
+                    const onMessage = queue.length > 0
+                        ? Promise.resolve()
+                        : new Promise((resolve) => {
+                            queueNonEmptyResolver = resolve;
+                        });
+                    await onMessage;
+                    return queue.shift();
+                },
+                /**
+                 * Adds a message to the queue.
+                 * Resolves the pending promise if needed.
+                 */
+                sendMessage(message) {
+                    queue.push(message);
+                    if (queueNonEmptyResolver !== null) {
+                        queueNonEmptyResolver();
+                        queueNonEmptyResolver = null;
+                    }
+                },
+            };
+        });
+        return `(${functionStr})()`;
+    }
+    /** Creates a ChannelProxy in the given realm. */
+    static async #createAndGetHandleInRealm(realm) {
+        const createChannelHandleResult = await realm.cdpClient.sendCommand('Runtime.evaluate', {
+            expression: this.#createChannelProxyEvalStr(),
+            contextId: realm.executionContextId,
+            serializationOptions: {
+                serialization: "idOnly" /* Protocol.Runtime.SerializationOptionsSerialization.IdOnly */,
+            },
+        });
+        if (createChannelHandleResult.exceptionDetails ||
+            createChannelHandleResult.result.objectId === undefined) {
+            throw new Error(`Cannot create channel`);
+        }
+        return createChannelHandleResult.result.objectId;
+    }
+    /** Gets a handle to `sendMessage` delegate from the ChannelProxy handle. */
+    static async #createSendMessageHandle(realm, channelHandle) {
+        const sendMessageArgResult = await realm.cdpClient.sendCommand('Runtime.callFunctionOn', {
+            functionDeclaration: String((channelHandle) => {
+                return channelHandle.sendMessage;
+            }),
+            arguments: [{ objectId: channelHandle }],
+            executionContextId: realm.executionContextId,
+            serializationOptions: {
+                serialization: "idOnly" /* Protocol.Runtime.SerializationOptionsSerialization.IdOnly */,
+            },
+        });
+        // TODO: check for exceptionDetails.
+        return sendMessageArgResult.result.objectId;
+    }
+    /** Starts listening for the channel events of the provided ChannelProxy. */
+    async #startListener(realm, channelHandle, eventManager) {
+        // noinspection InfiniteLoopJS
+        for (;;) {
+            try {
+                const message = await realm.cdpClient.sendCommand('Runtime.callFunctionOn', {
+                    functionDeclaration: String(async (channelHandle) => await channelHandle.getMessage()),
+                    arguments: [
+                        {
+                            objectId: channelHandle,
+                        },
+                    ],
+                    awaitPromise: true,
+                    executionContextId: realm.executionContextId,
+                    serializationOptions: {
+                        serialization: "deep" /* Protocol.Runtime.SerializationOptionsSerialization.Deep */,
+                        maxDepth: this.#properties.serializationOptions?.maxObjectDepth ??
+                            undefined,
+                    },
+                });
+                if (message.exceptionDetails) {
+                    throw new Error('Runtime.callFunctionOn in ChannelProxy', {
+                        cause: message.exceptionDetails,
+                    });
+                }
+                for (const browsingContext of realm.associatedBrowsingContexts) {
+                    eventManager.registerEvent({
+                        type: 'event',
+                        method: protocol_js_1.ChromiumBidi.Script.EventNames.Message,
+                        params: {
+                            channel: this.#properties.channel,
+                            data: realm.cdpToBidiValue(message, this.#properties.ownership ?? "none" /* Script.ResultOwnership.None */),
+                            source: realm.source,
+                        },
+                    }, browsingContext.id);
+                }
+            }
+            catch (error) {
+                // If an error is thrown, then the channel is permanently broken, so we
+                // exit the loop.
+                this.#logger?.(log_js_1.LogType.debugError, error);
+                break;
+            }
+        }
+    }
+    /**
+     * Returns a handle of ChannelProxy from window's property which was set there
+     * by `getEvalInWindowStr`. If window property is not set yet, sets a promise
+     * resolver to the window property, so that `getEvalInWindowStr` can resolve
+     * the promise later on with the channel.
+     * This is needed because `getEvalInWindowStr` can be called before or
+     * after this method.
+     */
+    async #getHandleFromWindow(realm) {
+        const channelHandleResult = await realm.cdpClient.sendCommand('Runtime.callFunctionOn', {
+            functionDeclaration: String((id) => {
+                const w = window;
+                if (w[id] === undefined) {
+                    // The channelProxy is not created yet. Create a promise, put the
+                    // resolver to window property and return the promise.
+                    // `getEvalInWindowStr` will resolve the promise later.
+                    return new Promise((resolve) => (w[id] = resolve));
+                }
+                // The channelProxy is already created by `getEvalInWindowStr` and
+                // is set into window property. Return it.
+                const channelProxy = w[id];
+                delete w[id];
+                return channelProxy;
+            }),
+            arguments: [{ value: this.#id }],
+            executionContextId: realm.executionContextId,
+            awaitPromise: true,
+            serializationOptions: {
+                serialization: "idOnly" /* Protocol.Runtime.SerializationOptionsSerialization.IdOnly */,
+            },
+        });
+        if (channelHandleResult.exceptionDetails !== undefined ||
+            channelHandleResult.result.objectId === undefined) {
+            throw new Error(`ChannelHandle not found in window["${this.#id}"]`);
+        }
+        return channelHandleResult.result.objectId;
+    }
+    /**
+     * String to be evaluated to create a ProxyChannel and put it to window.
+     * Returns the delegate `sendMessage`. Used to provide an argument for preload
+     * script. Does the following:
+     * 1. Creates a ChannelProxy.
+     * 2. Puts the ChannelProxy to window['${this.#id}'] or resolves the promise
+     *    by calling delegate stored in window['${this.#id}'].
+     *    This is needed because `#getHandleFromWindow` can be called before or
+     *    after this method.
+     * 3. Returns the delegate `sendMessage` of the created ChannelProxy.
+     */
+    getEvalInWindowStr() {
+        const delegate = String((id, channelProxy) => {
+            const w = window;
+            if (w[id] === undefined) {
+                // `#getHandleFromWindow` is not initialized yet, and will get the
+                // channelProxy later.
+                w[id] = channelProxy;
+            }
+            else {
+                // `#getHandleFromWindow` is already set a delegate to window property
+                // and is waiting for it to be called with the channelProxy.
+                w[id](channelProxy);
+                delete w[id];
+            }
+            return channelProxy.sendMessage;
+        });
+        const channelProxyEval = ChannelProxy.#createChannelProxyEvalStr();
+        return `(${delegate})('${this.#id}',${channelProxyEval})`;
+    }
+}
+exports.ChannelProxy = ChannelProxy;
+//# sourceMappingURL=ChannelProxy.js.map