test: fix flaky watch-mode tests with atomic writes#3
Open
mcollina wants to merge 1 commit into
Open
Conversation
Use atomic file writes (write to temp file then rename) instead of direct writeFileSync in watch-mode tests. writeFileSync is not atomic - it truncates the file before writing, creating a race window where the ESM loader can read an empty/partial file and produce SyntaxErrors. This fix affects: - test/sequential/test-watch-mode-worker.mjs - test/sequential/test-watch-mode.mjs Both now write to a temp file and rename atomically, eliminating the truncation race. The interval timing in the worker test is also aligned with the main test (2500ms) to reduce the race probability. Refs: nodejs#62275
mcollina
pushed a commit
that referenced
this pull request
Jun 7, 2026
This function call can fail with `Z_VERSION_ERROR` if the compiled
library vs loaded library mismatched in version number or in
stream structure size.
In those cases, zlib doesn't initialize the `strm_.msg` field to
null. Therefore, when a `CompressionError` object is created via
`ErrorForMessage()`, it can read a stale or uninitialized `strm_.msg`
pointer that will cause a crash.
Example ASAN report:
```
AddressSanitizer: SEGV on unknown address
#0 __strlen_avx2
string/../sysdeps/x86_64/multiarch/strlen-avx2.S:76
#1 strlen (/work/node/out/Debug/node+0x1a42ab7)
#2 v8::(anonymous namespace)::StringLength(char const*)
/work/node/out/../deps/v8/src/api/api.cc:7581:16
#3 v8::(anonymous namespace)::StringLength(unsigned char const*)
/work/node/out/../deps/v8/src/api/api.cc:7587:10
#4 v8::String::NewFromOneByte(v8::Isolate*,
unsigned char const*, v8::NewStringType, int)
/work/node/out/../deps/v8/src/api/api.cc:7677:3
#5 node::OneByteString(v8::Isolate*,
char const*, int, v8::NewStringType)
/work/node/out/../src/util-inl.h:166:10
#6 node::(anonymous namespace)::CompressionStream<
node::(anonymous namespace)::ZlibContext>
::EmitError(node::(anonymous namespace)
::CompressionError const&)
/work/node/out/../src/node_zlib.cc:565:7
#7 node::(anonymous namespace)::CompressionStream<
node::(anonymous namespace)::ZlibContext>
::CheckError()
/work/node/out/../src/node_zlib.cc:519:5
#8 node::(anonymous namespace)::CompressionStream<
node::(anonymous namespace)::ZlibContext>
::AfterThreadPoolWork(int)
/work/node/out/../src/node_zlib.cc:543:10
#9 node::ThreadPoolWork::ScheduleWork()
::'lambda'(uv_work_s*, int)
::operator()(uv_work_s*, int) const
/work/node/out/../src/threadpoolwork-inl.h:57:15
nodejs#10 node::ThreadPoolWork::ScheduleWork()
::'lambda'(uv_work_s*, int)
::__invoke(uv_work_s*, int)
/work/node/out/../src/threadpoolwork-inl.h:48:7
nodejs#11 uv__work_done /work/libuv-1.51.0/src/threadpool.c:330:5
nodejs#12 uv__async_io.part.0
/work/libuv-1.51.0/src/unix/async.c:208:5
```
Signed-off-by: ndossche <nora.dossche@ugent.be>
PR-URL: nodejs#63476
Reviewed-By: Anna Henningsen <anna@addaleax.net>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Use atomic writes (write to temp file then rename) instead of direct writeFileSync in watch-mode tests to eliminate the truncation race with the ESM loader.