Chrome扩展contextMenus的sendResponse在部分页面失效求助

报错Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist.的核心原因是：目标标签页中未注入对应的content script（比如页面在扩展安装/启用前打开，或service worker发送消息时content script未完成初始化），导致background无法建立消息连接。

以下是修复后的完整代码及说明：

1. 更新manifest.json #

添加scripting权限，用于动态注入content script：

{
    "manifest_version": 3,
    "name": "Words Repeater",
    "description": "Repeat words what you want to memorize",
    "version": "1.0.0",
    "permissions": ["contextMenus", "activeTab", "tabs", "scripting"],
    "action": {
        "default_popup": "popup.html"
    },
    "background": {
        "service_worker": "./js/background.js"
    },
    "content_scripts": [
        {
          "matches": ["http://*/*", "https://*/*"],
          "js": ["./js/content.js"]
        }
    ]
}

2. 修改background.js #

修正参数错误，优化右键菜单触发条件，并添加动态注入content script的逻辑：

//background.js

chrome.runtime.onInstalled.addListener((details) => {
    chrome.contextMenus.create({
        id: 'addWords',
        title: "Send \"%s\" to background",
        contexts: ['selection'] // 仅在选中文本时显示菜单，避免无效触发
    })
});

function getSelection(info, tab) {
    if (info.menuItemId === "addWords") {
        const sendRequest = () => {
            chrome.tabs.sendMessage(tab.id, {action: "getSelection"}, (response) => {
                if (!chrome.runtime.lastError) {
                    console.log(response);
                }
            });
        };

        // 先尝试发送消息，失败则动态注入content script后重试
        chrome.tabs.sendMessage(tab.id, {action: "getSelection"}, (response) => {
            if (chrome.runtime.lastError) {
                chrome.scripting.executeScript({
                    target: {tabId: tab.id},
                    files: ["./js/content.js"]
                }, () => {
                    if (!chrome.runtime.lastError) {
                        sendRequest();
                    }
                });
            } else {
                console.log(response);
            }
        });
    }
}

chrome.contextMenus.onClicked.addListener(getSelection);

3. content.js（保持原有逻辑，可选优化句子提取） #

原代码可正常使用，若要优化句子提取（避免将缩写如Mr.误判为句末），可调整分割逻辑，这里保留原代码：

//content.js
chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
    if(request.action === "getSelection"){
        let selection = window.getSelection();
        if(selection.toString() !== ""){
            let arr = selection.anchorNode.data.split(".");
            let word = selection.toString();
            let sentence = arr.find(str => str.includes(word))
            alert(word);
            sendResponse({word: word, sentence: sentence});
        }
    }
})

修复说明 #

• 动态注入content script：当自动注入失效时，通过chrome.scripting.executeScript手动注入，确保接收端存在。
• 优化菜单触发条件：将contexts设为selection，仅在用户选中文本时显示右键菜单，减少无效操作。
• 错误处理：捕获消息发送和脚本注入的错误，避免控制台报错影响扩展运行。

内容的提问来源于stack exchange，提问作者Ma Twickenham