[Flight & DevTools] Strip the whole "async " prefix from V8 stack fra…

Commit ccea5fd authored [Flight & DevTools] Strip the whole "async " prefix from V8 stack frame names (#37608) ## Summary V8 prefixes async call sites with async when it prints a stack, like this: Error: boom at inner (/tmp/asy.js:1:44) at async outerName (/tmp/asy.js:2:30) parseStackTraceFromChromeStack captures async outerName as the frame name and strips the prefix here: js } else if (name.startsWith('async ')) { name = name.slice(5); isAsync = true; } 'async ' is six characters, so slice(5) leaves the space behind and the frame name comes back as ' outerName' rather than 'outerName'. I noticed it while reading the parser, and it is not purely cosmetic: that name is the first element of the ReactFunctionLocation returned by extractLocationFromComponentStack and extractLocationFromOwnerStack, which backend/fiber/renderer.js stores as instance.source. Any async component whose frame reaches that path is recorded under a name with a stray leading space. The same line exists in packages/react-server/src/ReactFlightStackConfigV8.js, which the DevTools file is a copy of. After review I fixed it in this PR as well, in a second commit. There it only matters on the fallback path that parses an already formatted stack string, when the error's stack was read or assigned before React reaches it. #37130 is open on that file too, but it does not touch these lines. ## How did you test this change? I first confirmed the format V8 actually emits, rather than assuming it: $ node -e 'async function inner(){await null;throw new Error("boom")} async function outerName(){await inner()} outerName().catch(e=>console.log(e.stack))' Error: boom at inner ([eval]:1:52) at async outerName ([eval]:2:33) Then I added a case to the existing extractLocationFromComponentStack block in utils-test.js. Against main it fails with exactly the leading space: ● utils › extractLocationFromComponentStack › should strip the async prefix from a frame name - Expected - 1 + Received + 1 Array [ - "Comments", + " Comments", "https://react.dev/_next/static/chunks/848-122f91e9565d9ffa.js", 5, 9236, ] With the one-character fix applied: $ yarn test --build --project=devtools -r=experimental utils-test PASS packages/react-devtools-shared/src/__tests__/utils-test.js Tests: 63 passed, 63 total I also ran the whole DevTools project before and after to check I was not moving anything else. Both runs end at 9 failed, 4 failed suites, the same test names each time (componentStacks, console, inspectedElement, legacy/inspectElement), so those failures are pre-existing on main in my environment and unrelated to this change. The only difference between the two runs is my new test: 586 passed before, 587 after. For the Flight side I added ReactFlightStackConfigV8-test.js, which assigns a formatted stack to an error and checks what parseStackTrace returns. Against main it fails with the same leading space (" outerName"); with the fix it passes on stable and experimental in development. It is gated to __DEV__ because that fallback goes through the DEV-only stack cache. ReactFlightServer-test and ReactFlightAsyncDebugInfo-test still pass next to it (23 tests). prettier and eslint are clean on all changed files. yarn flow dom-node reported no errors for the DevTools commit; I did not rerun Flow after the one-character Flight change. AI tools used1 parent 564923c commit ccea5fd 4 files changed Lines changed: 52 additions & 2 deletions File tree - packages - react-server/src - tests Lines changed: 13 additions & 0 deletions | Original file line number | Diff line number | Diff line change | | |---|---|---|---| | ||| 395 | 395 | | | 396 | 396 | | | 397 | 397 | | | | 398 | + | | | 399 | + | | | 400 | + | | | 401 | + | | | 402 | + | | | 403 | + | | | 404 | + | | | 405 | + | | | 406 | + | | | 407 | + | | | 408 | + | | | 409 | + | | | 410 | + | | 398 | 411 | | | 399 | 412 | | | 400 | 413 | | | | Lines changed: 1 addition & 1 deletion | Original file line number | Diff line number | Diff line change | | |---|---|---|---| | ||| 45 | 45 | | | 46 | 46 | | | 47 | 47 | | | 48 | | - | | | 48 | + | | 49 | 49 | | | 50 | 50 | | | 51 | 51 | | | | | Original file line number | Diff line number | Diff line change | | |---|---|---|---| | ||| 237 | 237 | | | 238 | 238 | | | 239 | 239 | | | 240 | | - | | | 240 | + | | 241 | 241 | | | 242 | 242 | | | 243 | 243 | | | | Lines changed: 37 additions & 0 deletions | Original file line number | Diff line number | Diff line change | | |---|---|---|---| | ||| | 1 | + | | | 2 | + | | | 3 | + | | | 4 | + | | | 5 | + | | | 6 | + | | | 7 | + | | | 8 | + | | | 9 | + | | | 10 | + | | | 11 | + | | | 12 | + | | | 13 | + | | | 14 | + | | | 15 | + | | | 16 | + | | | 17 | + | | | 18 | + | | | 19 | + | | | 20 | + | | | 21 | + | | | 22 | + | | | 23 | + | | | 24 | + | | | 25 | + | | | 26 | + | | | 27 | + | | | 28 | + | | | 29 | + | | | 30 | + | | | 31 | + | | | 32 | + | | | 33 | + | | | 34 | + | | | 35 | + | | | 36 | + | | | 37 | + | 0 commit comments