Migrate unit tests from XCTest to Swift Testing by eseay · Pull Request #404 · connectrpc/connect-swift

eseay · 2026-07-19T02:07:39Z

Summary

Migrates all 15 XCTest suites under Tests/UnitTests (both ConnectLibraryTests and ConnectPluginUtilitiesTests) to Swift Testing, one suite per commit for reviewability.

XCTestCase classes → struct suites; XCTAssert* → #expect, XCTUnwrap → #require, XCTFail → Issue.record, error-inspection closures → typed #expect(throws:).
The four near-identical FilePathComponentsTests methods are collapsed into a single parameterized @Test(arguments:).
Every @Test function carries @available(iOS 13, *) because the package's iOS floor is 12, below Swift Testing's iOS 13 minimum. The annotation cannot live on the suite type: the @Test macro rejects members of @available types ("Attribute 'Test' cannot be applied to this function because it has been marked '@available(iOS 13, *)'"), so per-function is the only supported form.
InterceptorIntegrationTests is @Suite(.serialized) (documented in-source): Swift Testing parallelizes by default, and these tests share the live conformance reference server and assert timing-sensitive URLSession metrics. Its sleep(1) is now a cooperative Task.sleep so it no longer blocks a pool thread.
Removes the now-dead XCTest lint rules (empty_xctest_method, xct_specific_matcher, custom xctestcase) and adds a swift_testing_over_xctest rule to prevent drift back to XCTest.

No Package.swift, CI, or Makefile changes were needed: swift test discovers Swift Testing tests under the existing swift-tools-version:5.6 manifest.

Test plan

Full swift test against a running conformance reference server (the make testunit flow): 69 tests in 15 suites pass — the original 72 methods minus the 4 collapsed into 1 parameterized test, so no test was lost in discovery.
xcodebuild build-for-testing for iOS Simulator succeeds, verifying the iOS 12 deployment target compiles with the availability annotations.
swiftlint lint --strict is clean for all touched files.
Multi-angle review of the full diff; findings were either remediated (non-blocking sleep, XCTest lint guard) or refuted with compiler/runtime evidence.

🤖 Generated with Claude Code

…-resend hang) (#407) ## Summary Fixes the long-standing flakiness in the `run-conformance-tests` CI job, where a run would emit a nameless `timed out waiting for result from client` line and then, ~5s later, a burst of 80–100 `FAILED: … failed to get result from client` lines spanning unrelated test categories. **Root cause: the conformance client was crashing/hanging *between* test cases, not failing individual tests.** `Tests/ConformanceClient/Sources/main.swift` reads length-prefixed requests from stdin and runs them **serially** — one process, one test at a time. When the process dies or wedges between tests, the runner times out on the in-flight test and then fails every test still queued behind it at once. That is why the "failing" tests looked random and unrelated each run — they were never actually run. Two distinct underlying bugs produced this same signature; both are fixed here. ### 1. `NIOHTTPClient` crash on deinit (SIGTRAP) Reproduced under load with matching `.ips` crash reports. If the last strong reference to a `NIOHTTPClient` is dropped while an `EventLoopFuture` callback (e.g. the connect callback in `connectChannelAndMultiplexerIfNeeded()`) holds a temporary strong reference upgraded from `[weak self]`, the client is deallocated **on its own event loop thread**. `deinit` then called `syncShutdownGracefully()`, which traps with a precondition failure when invoked from an event loop — killing the process with SIGTRAP, silently, between test cases. **Fix:** use the asynchronous `shutdownGracefully(_:)`, which is safe to call from any thread including the group's own event loops. ### 2. `URLSessionStream` hang on request-body resend Reproduced locally and in CI (runs `29702874348`, `29702882058`). Every hung test was a streaming RPC over `URLSessionHTTPClient`; in one case even a 2-second `TimeoutTimer` calling `task.cancel()` could not produce a completion callback. When a connection is dropped and retried, URLSession asks for the request body again via `urlSession(_:task:needNewBodyStream:)`. A bound stream pair can't be replayed, so `requestBodyStream` vends `nil` (#399). Contrary to the assumption there, CFNetwork does **not** fail the task when given a `nil` body stream — it can leave the task parked indefinitely with no delegate callbacks, wedging the serial client. **Fix:** cancel the task when a resend is requested, guaranteeing `didCompleteWithError` is delivered, and surface the failure as `.unavailable` with a descriptive message (rather than a misleading `canceled`) since it is a retriable connection-level failure. ### 3. Diagnosability The conformance client now logs `starting <test> …` / `finished <test>` to stderr before/after each case. The runner surfaces client stderr, so a future wedge shows exactly which test/protocol/codec/streamType was in flight — the piece of information missing from every prior CI failure log, and what pinpointed both bugs here. ## Validation - **NIO crash:** 1,071 suite runs with the fix while the machine was verifiably awake (534 nio / 537 urlsession) produced **zero NIO crashes and zero NIO bursts**; ~17 crashes were expected at the pre-fix rate. Unit tests: 69/69 pass. - **URLSession hang:** validated on the real macos-26 CI runners (in progress on this branch). - Note for reproduction: laptop sleep fires the runner's wall-clock timeouts and produces fake "burst" failures on wake — all local runs were cross-checked against `pmset -g log` and sleep-window runs discarded. ## Notes This branch was previously stacked on #404 (Swift Testing migration); it has been rebased directly onto `main` so this PR contains only the 3 conformance-fix commits. --------- Signed-off-by: Eddie Seay <eddie.seay@cfacorp.com>

Replaces the deprecated NIOHTTP2.HTTP2StreamMultiplexer with NIOHTTP2Handler.StreamMultiplexer (the inline stream multiplexer) and moves pipeline configuration onto ChannelPipeline.SynchronousOperations. This eliminates all Sendable/deprecation warnings emitted when building ConnectNIO against recent swift-nio-http2 releases, and allows dropping the @preconcurrency imports of NIOCore and NIOSSL. Fixes #408. Signed-off-by: Eddie Seay <eddie.seay@cfacorp.com>

Signed-off-by: Eddie Seay <eddie.seay@cfacorp.com>

@test

Converts the ConnectPluginUtilitiesTests target from XCTest to Swift Testing, collapsing four near-identical test methods into a single parameterized @test. Validates that Swift Testing discovery works with the existing swift-tools-version and that the iOS 12 deployment target builds with @available(iOS 13, *) on test functions. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Signed-off-by: Eddie Seay <eddie.seay@cfacorp.com>

@available