Unhandled promise rejection (lighthouse-core/gather/fetcher.js)

[mikedijkstra]

We're seeing a number of errors being thrown from lighthouse-core/gather/fetcher.js as unhandled promise rejections.

Examples of errors:

• Protocol error (Fetch.failRequest): Fetch domain is not enabled
• Protocol error (Fetch.continueRequest): Invalid InterceptionId.
• Error: Invalid response status code: 404
• Invalid response status code: 403
• Invalid response status code: 301

Error output

Unhandled Rejection at: Promise Promise {
  <rejected> Error: Invalid response status code: 404
      at ./node_modules/lighthouse/lighthouse-core/gather/fetcher.js:119:18
      at Fetcher._onRequestPaused (./node_modules/lighthouse/lighthouse-core/gather/fetcher.js:75:13)
      at EventEmitter.emit (events.js:315:20)
      at EventEmitter.emit (domain.js:482:12)
      at Driver._handleProtocolEvent (./node_modules/lighthouse/lighthouse-core/gather/driver.js:299:24)
      at EventEmitter.emit (events.js:315:20)
      at EventEmitter.emit (domain.js:482:12)
      at CalibreProtocol.emitProtocolEvent (./node_modules/lighthouse/lighthouse-core/gather/connections/connection.js:148:24)
      at CalibreProtocol.handleRawMessage (./node_modules/lighthouse/lighthouse-core/gather/connections/connection.js:113:12)
      at WebSocket.<anonymous> (./node_modules/lighthouse/lighthouse-core/gather/connections/cri.js:72:37)
} reason: Error: Invalid response status code: 404
    at ./node_modules/lighthouse/lighthouse-core/gather/fetcher.js:119:18
    at Fetcher._onRequestPaused (./node_modules/lighthouse/lighthouse-core/gather/fetcher.js:75:13)
    at EventEmitter.emit (events.js:315:20)
    at EventEmitter.emit (domain.js:482:12)
    at Driver._handleProtocolEvent (./node_modules/lighthouse/lighthouse-core/gather/driver.js:299:24)
    at EventEmitter.emit (events.js:315:20)
    at EventEmitter.emit (domain.js:482:12)
    at CalibreProtocol.emitProtocolEvent (./node_modules/lighthouse/lighthouse-core/gather/connections/connection.js:148:24)
    at CalibreProtocol.handleRawMessage (./node_modules/lighthouse/lighthouse-core/gather/connections/connection.js:113:12)
    at WebSocket.<anonymous> (./node_modules/lighthouse/lighthouse-core/gather/connections/cri.js:72:37)
(node:25717) PromiseRejectionHandledWarning: Promise rejection was handled asynchronously (rejection id: 10)
Error: Invalid response status code: 404
    at ./node_modules/lighthouse/lighthouse-core/gather/fetcher.js:119:18
    at Fetcher._onRequestPaused (./node_modules/lighthouse/lighthouse-core/gather/fetcher.js:75:13)
    at EventEmitter.emit (events.js:315:20)
    at EventEmitter.emit (domain.js:482:12)
    at Driver._handleProtocolEvent (./node_modules/lighthouse/lighthouse-core/gather/driver.js:299:24)
    at EventEmitter.emit (events.js:315:20)
    at EventEmitter.emit (domain.js:482:12)
    at CalibreProtocol.emitProtocolEvent (./node_modules/lighthouse/lighthouse-core/gather/connections/connection.js:148:24)
    at CalibreProtocol.handleRawMessage (./node_modules/lighthouse/lighthouse-core/gather/connections/connection.js:113:12)
    at WebSocket.<anonymous> (./node_modules/lighthouse/lighthouse-core/gather/connections/cri.js:72:37)

I'm seeing the error in Node and when using the Lighthouse CLI.

Provide the steps to reproduce

Run:

lighthouse https://www.clarin.com/deportes/basquet/ginobili-volvio-hacer-magia-definicion-exquisita_0_H16J9aAaZ.html --view

What is the current behavior?

Lighthouse returns Unhandled Rejection. Reason: Error: Invalid response status code: 404. See full output.

What is the expected behavior?

Lighthouse report is generated and opened in the browser

Environment Information

• Affected Channels: CLI, Node
• Lighthouse version: 6.1
• Chrome version: 83.0.4103.116
• Node.js version: 12.18.0
• Operating System: Mac, Linux

[patrickhulce]

Thanks for filing @mikedijkstra! The sendCommand ones are an easy fix but I'm not immediately seeing how the invalid status code ones are unhandled 🤔 we'll have to investigate.

My preliminary investigation results:

• The only place we use the fetcher is in source maps where it is await'd properly, so it must be internal to fetcher.
• I was guessing that requestInterceptionPromise was rejecting after our timeout rejected and that somehow leads to the unhandled rejection.
  

  lighthouse/lighthouse-core/gather/fetcher.js

  Lines 171 to 174 in c139d72

  	return Promise.race([
  	timeoutPromise,
  	requestInterceptionPromise,
  	]).finally(() => clearTimeout(timeoutHandle));

• This doesn't hold up with my understanding of Promise.race though, and toy example won't repro either... not sure how it's happening

const rejectIn1s = new Promise((r, reject) => setTimeout(() => reject('foo'), 1000)) // this doesn't lead to an unhandled promise rejection
const resolvein500ms = new Promise(r => setTimeout(r, 500))

Promise.race([rejectIn1s, resolvein500ms])
  .then(() => console.log('done'))
  .finally(() => console.log('finally'))

[connorjclark]

It's being rejected before the evaluation ends.