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Cannot read properties of undefined (reading 'transferSize') #17
Description
I was trying to incorporate this into a small CLI project(not within a browser), but every request appears to fail, but they are actually succeeding in the background, the error message just isn't very good.
I chased it down to this line:
For my testing, I simply tried to log the matching entries via:
var perf = performance.getEntriesByName(url).slice(-1)[0]; // get latest perf timing
console.log(perf); // <---- This is always undefinedCloser inspection revealed that the name property of PerformanceResourceTiming being set to a URL object instead of a string. I'm unfamiliar with the Performance API, but the spec seems to state that the name property would be a string rather than an object, but it's not immediately clear to me if that is correct.
https://developer.mozilla.org/en-US/docs/Web/API/PerformanceEntry/name
The following is just a dump of the PerformanceResourceTiming itself, if I dont use getEntriesByName. You can see the entries exist, but they are not being matched via URL for some reason.
Error fetching https://speed.cloudflare.com/__down?bytes=0: TypeError: Cannot read properties of undefined (reading 'transferSize')
// console.log(performance.getEntries().slice(-1)[0]);
PerformanceResourceTiming {
name: URL {
href: 'https://speed.cloudflare.com/__down?bytes=0',
origin: 'https://speed.cloudflare.com',
protocol: 'https:',
username: '',
password: '',
host: 'speed.cloudflare.com',
hostname: 'speed.cloudflare.com',
port: '',
pathname: '/__down',
search: '?bytes=0',
searchParams: URLSearchParams { 'bytes' => '0' },
hash: ''
},
entryType: 'resource',
startTime: 3013.801200002432,
duration: -3013.801200002432,
initiatorType: 'fetch',
nextHopProtocol: undefined,
workerStart: 0,
redirectStart: 0,
redirectEnd: 0,
fetchStart: 3013.801200002432,
domainLookupStart: undefined,
domainLookupEnd: undefined,
connectStart: undefined,
connectEnd: undefined,
secureConnectionStart: undefined,
requestStart: 0,
responseStart: 0,
responseEnd: 0,
transferSize: 300,
encodedBodySize: 0,
decodedBodySize: 0
}
Activity
vasturiano commentedon May 26, 2023
@bruceharrison1984 thanks for reaching out.
The issue that you're experiencing is essentially because the
PerformanceResponseTimingapi is not really fully implemented in Node.js, even up to the latest version (v20).The issue of
getEntriesByNamereturning a URL object instead of astring(contrary to the W3C spec) is only the first in a long series of obstacles caused by that API only being partially implemented in node, specifically their HTTP client module: undici.There is more info on this issue in that repo.
This essentially means that currently this module is not compatible with Node.js environments. It requires a browser environment, where the API spec is fully implemented and conforming to the spec.
Thus, integrating it in a CLI poses quite difficult challenges until the time that node fully supports it.
bruceharrison1984 commentedon May 26, 2023
@vasturiano Thanks for the response. I presumed it was something along those lines but it's nice to hear some verification as well. I'm going to mark this as closed.
jasonz1987 commentedon Jun 16, 2023
same issues on react native app, so is there a plan to add a react native plugin for this ? maybe, we should replace the browser web api with https://github.com/oblador/react-native-performance
ToshB commentedon Dec 20, 2023
nodejs/undici#2481 was just merged, which gets us one step closer to getting a working CLI version. Still need to wait for undici to get updated in Node though, but replacing the isomorphic-fetch-polyfill with undici (main) in this library seems to give us node compatibility now.