Hide CloseToken frames from stack traces

[osipxd]

Subsystem
ktor-io

Motivation
wrapCause and throwOrNull add some noise to stacktraces

Solution
Make them inline, so they don't add any trace frames.

Before:

io.ktor.utils.io.ClosedByteChannelException: Socket timeout has expired [url=http://localhost:60230/sse/delay/2000, socket_timeout=1000] ms
	at io.ktor.utils.io.CloseToken$wrapCause$1.invoke(CloseToken.kt:17)
	at io.ktor.utils.io.CloseToken$wrapCause$1.invoke(CloseToken.kt:17)
	at io.ktor.utils.io.CloseToken.wrapCause(CloseToken.kt:23)
	at io.ktor.utils.io.CloseToken.wrapCause$default(CloseToken.kt:16)
	at io.ktor.utils.io.ByteChannel.cancel(ByteChannel.kt:145)
	at io.ktor.utils.io.ByteWriteChannelOperationsKt.close(ByteWriteChannelOperations.kt:130)
	at io.ktor.utils.io.ByteReadChannelOperationsKt.copyTo(ByteReadChannelOperations.kt:213)
	at io.ktor.utils.io.ByteReadChannelOperationsKt$copyTo$2.invokeSuspend(ByteReadChannelOperations.kt)
	at _COROUTINE._BOUNDARY._(CoroutineDebugging.kt:42)
	at io.ktor.utils.io.ByteChannel.awaitContent(ByteChannel.kt:307)
	at io.ktor.utils.io.ByteReadChannelOperationsKt.internalReadLineTo(ByteReadChannelOperations.kt:686)
	at io.ktor.utils.io.ByteReadChannelOperationsKt.readLineStrict(ByteReadChannelOperations.kt:638)
	at io.ktor.client.engine.apache5.Apache5HttpClientTest$testSocketTimeoutWithCustomConnectionManager$1$1$1.invokeSuspend(Apache5HttpClientTest.kt:44)
	at io.ktor.client.statement.HttpStatement.execute(HttpStatement.kt:77)
	at io.ktor.client.engine.apache5.Apache5HttpClientTest$testSocketTimeoutWithCustomConnectionManager$1.invokeSuspend(Apache5HttpClientTest.kt:41)

After:

io.ktor.utils.io.ClosedByteChannelException: Socket timeout has expired [url=http://localhost:58759/sse/delay/2000, socket_timeout=1000] ms
	at io.ktor.utils.io.ByteChannel.cancel(ByteChannel.kt:446)
	at io.ktor.utils.io.ByteWriteChannelOperationsKt.close(ByteWriteChannelOperations.kt:130)
	at io.ktor.utils.io.ByteReadChannelOperationsKt.copyTo(ByteReadChannelOperations.kt:213)
	at io.ktor.utils.io.ByteReadChannelOperationsKt$copyTo$2.invokeSuspend(ByteReadChannelOperations.kt)
	at _COROUTINE._BOUNDARY._(CoroutineDebugging.kt:42)
	at io.ktor.utils.io.ByteChannel.awaitContent(ByteChannel.kt:307)
	at io.ktor.utils.io.ByteReadChannelOperationsKt.internalReadLineTo(ByteReadChannelOperations.kt:686)
	at io.ktor.utils.io.ByteReadChannelOperationsKt.readLineStrict(ByteReadChannelOperations.kt:638)
	at io.ktor.client.engine.apache5.Apache5HttpClientTest$testSocketTimeoutWithCustomConnectionManager$1$1$1.invokeSuspend(Apache5HttpClientTest.kt:44)
	at io.ktor.client.statement.HttpStatement.execute(HttpStatement.kt:77)
	at io.ktor.client.engine.apache5.Apache5HttpClientTest$testSocketTimeoutWithCustomConnectionManager$1.invokeSuspend(Apache5HttpClientTest.kt:41)

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 78c6473f-1a4e-42aa-ad23-b5d2cf13694e

📥 Commits

Reviewing files that changed from the base of the PR and between 6d662e1 and 9cb2dfb.

📒 Files selected for processing (5)

• ktor-io/common/src/io/ktor/utils/io/ByteChannel.kt
• ktor-io/common/src/io/ktor/utils/io/CloseToken.kt
• ktor-io/common/src/io/ktor/utils/io/SinkByteWriteChannel.kt
• ktor-io/common/src/io/ktor/utils/io/SourceByteReadChannel.kt
• ktor-io/jvm/src/io/ktor/utils/io/jvm/javaio/Reading.kt

---

📝 Walkthrough

Walkthrough

This PR refactors CloseToken's wrapCause and throwOrNull from instance methods to inline extension functions within the companion object, then adds required imports across five source files to support existing cause-wrapping logic in channel implementations.

Changes

CloseToken Extension Refactoring

Layer / File(s)	Summary
Core Extension Functions ktor-io/common/src/io/ktor/utils/io/CloseToken.kt	wrapCause and throwOrNull move from instance methods to inline CloseToken extensions in companion object, preserving conditional handling of null, CopyableThrowable, CancellationException, and other throwables.
Common Channel Imports ktor-io/common/src/io/ktor/utils/io/ByteChannel.kt, ktor-io/common/src/io/ktor/utils/io/SinkByteWriteChannel.kt, ktor-io/common/src/io/ktor/utils/io/SourceByteReadChannel.kt	Imports for CloseToken.Companion.wrapCause and CloseToken.Companion.throwOrNull are added to support existing closedCause and error-translation accessors.
JVM-Specific Imports ktor-io/jvm/src/io/ktor/utils/io/jvm/javaio/Reading.kt	Import for CloseToken.wrapCause is added to support RawSourceChannel.closedCause accessor.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• ktorio/ktor#5575: Related refactoring that converts CloseToken.wrapCause/throwOrNull into companion receiver extensions and updates imports for channel close cause wrapping and propagation.

Suggested reviewers

• e5l
• bjhham

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Hide CloseToken frames from stack traces' accurately describes the main objective of the PR—refactoring wrapCause and throwOrNull functions to be inline to eliminate stack-trace noise.
Description check	✅ Passed	The PR description includes all required template sections: Subsystem (ktor-io), Motivation (wrapCause/throwOrNull add noise), and Solution (make them inline). It also provides concrete before/after stack-trace examples demonstrating the improvement.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch osipxd/closetoken-stacktrace

---

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[bjhham]

Good idea, the traces are much cleaner!