Created
February 19, 2019 21:28
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Intercept responses with chrome and puppeteer
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const puppeteer = require('puppeteer'); | |
const prettier = require('prettier'); | |
const atob = require('atob'); | |
const btoa = require('btoa'); | |
const scriptUrlPatterns = [ | |
'*' | |
] | |
const requestCache = new Map(); | |
async function interceptRequestsForPage(page) { | |
const client = await page.target().createCDPSession(); | |
await client.send('Network.enable'); | |
await client.send('Network.setRequestInterception', { | |
patterns: scriptUrlPatterns.map(pattern => ({ | |
urlPattern: pattern, resourceType: 'Script', interceptionStage: 'HeadersReceived' | |
})) | |
}); | |
client.on('Network.requestIntercepted', async ({ interceptionId, request, responseHeaders, resourceType }) => { | |
console.log(`Intercepted ${request.url} {interception id: ${interceptionId}}`); | |
const response = await client.send('Network.getResponseBodyForInterception',{ interceptionId }); | |
const contentTypeHeader = Object.keys(responseHeaders).find(k => k.toLowerCase() === 'content-type'); | |
let newBody, contentType = responseHeaders[contentTypeHeader]; | |
if (requestCache.has(response.body)) { | |
newBody = requestCache.get(response.body); | |
} else { | |
const bodyData = response.base64Encoded ? atob(response.body) : response.body; | |
try { | |
if (resourceType === 'Script') newBody = prettier.format(bodyData, { parser: 'babel' }) | |
else newBody === bodyData | |
} catch(e) { | |
console.log(`Failed to process ${request.url} {interception id: ${interceptionId}}: ${e}`); | |
newBody = bodyData | |
} | |
requestCache.set(response.body, newBody); | |
} | |
const newHeaders = [ | |
'Date: ' + (new Date()).toUTCString(), | |
'Connection: closed', | |
'Content-Length: ' + newBody.length, | |
'Content-Type: ' + contentType | |
]; | |
console.log(`Continuing interception ${interceptionId}`) | |
client.send('Network.continueInterceptedRequest', { | |
interceptionId, | |
rawResponse: btoa('HTTP/1.1 200 OK' + '\r\n' + newHeaders.join('\r\n') + '\r\n\r\n' + newBody) | |
}); | |
}); | |
} | |
(async function main(){ | |
const browser = await puppeteer.launch({ | |
headless:false, | |
defaultViewport:null, | |
devtools: true, | |
args: ['--window-size=1920,1170','--window-position=0,0'] | |
}); | |
const page = (await browser.pages())[0]; | |
await interceptRequestsForPage(page); | |
browser.on('targetcreated', async (target) => { | |
const page = await target.page(); | |
await interceptRequestsForPage(page); | |
}) | |
})() |
TypeError: Cannot read properties of null (reading 'target') I keep having this error why??!
browser.on('targetcreated', async function (target) {
const page = await target.page();
if (page) {
await interceptRequestsForPage(page);
}
});
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TypeError: Cannot read properties of null (reading 'target')
I keep having this error why??!