Chrome Extension: Intercept Requests

background.js

// https://chromedevtools.github.io/devtools-protocol/1-3/Network
chrome.browserAction.onClicked.addListener(async tab => {
  const target = { tabId: tab.id }
  // Ждем пока подключимся к debugger
  await new Promise((resolve, reject) => {
    chrome.debugger.attach(target, '1.3', result => {
      if (chrome.runtime.lastError) {
        reject(chrome.runtime.lastError)
      } else {
        resolve(result)
      }
    })
  })
  const sendCommand = (method, params) =>
    new Promise((resolve, reject) => {
      chrome.debugger.sendCommand(target, method, params, result => {
        if (chrome.runtime.lastError) {
          reject(chrome.runtime.lastError)
        } else {
          resolve(result)
        }
      })
    })
  chrome.debugger.onEvent.addListener(async (source, method, params) => {
    switch (method) {
      case 'Network.requestWillBeSent': {
        const { request } = params
        // request.url
        // request.method
        // request.headers
        // request.postData
        // request.hasPostData
        break
      }
      case 'Network.responseReceived': {
        const { requestId, response } = params
        // response.status
        // response.protocol
        // response.headers
        // response.mimeType
        // response.encodedDataLength
        console.log(response)
        // body string
        // base64Encoded true/false
        const result = await sendCommand('Network.getResponseBody', { requestId })
        // console.log(result.body)
        break
      }
    }
  })
  await sendCommand('Network.enable')
})

manifest.json

{
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {},
  "manifest_version": 2,
  "name": "Interceptor",
  "permissions": [
    "debugger"
  ],
  "version": "0.1.0"
}

// https://chromedevtools.github.io/devtools-protocol/1-3/Network
// https://stackoverflow.com/questions/8894461/updating-an-extension-button-dynamically-inspiration-required
const tabs = new Map()

chrome.browserAction.onClicked.addListener(async tab => {
  const status = tabs.get(tab.id)
  const target = { tabId: tab.id }
  if ('activated' === status) {
    // Надо значок как-то изменить
    chrome.debugger.detach(target, () => {
      if (chrome.runtime.lastError) {
        console.error(chrome.runtime.lastError)
      } else {
        tabs.set(tab.id, 'deactivated')
      }
    })
  } else {
    // Ждем пока подключимся к debugger
    await new Promise((resolve, reject) => {
      chrome.debugger.attach(target, '1.3', result => {
        if (chrome.runtime.lastError) {
          reject(chrome.runtime.lastError)
        } else {
          resolve(result)
        }
      })
    })
    const sendCommand = (method, params) => new Promise((resolve, reject) => {
      chrome.debugger.sendCommand(target, method, params, result => {
        if (chrome.runtime.lastError) {
          reject(chrome.runtime.lastError)
        } else {
          resolve(result)
        }
      })
    })
    chrome.debugger.onEvent.addListener(async (source, method, params) => {
      switch (method) {
        case 'Network.requestWillBeSent': {
          const { request } = params
          // request.url
          // request.method
          // request.headers
          // request.postData
          // request.hasPostData
          break
        }
        case 'Network.responseReceived': {
          const { requestId, response } = params
          // response.status
          // response.protocol
          // response.headers
          // response.mimeType
          // response.encodedDataLength
          // console.log(response)
          // body string
          // base64Encoded true/false
          // const result = await sendCommand('Network.getResponseBody', { requestId })
          // console.log(result.body)
          break
        }
      }
    })
    await sendCommand('Network.enable')
    tabs.set(tab.id, 'activated')
  }
})

chrome.browser.tabs.onRemoved.addListener(({ tabId }) => tabs.delete(tabId))