Summary

• Each feature factory (KnownTests, TestManagement, TestImpactAnalysis, GitUploader) takes the specific *Api it needs and calls it via try await; the tracerSettings call in DDTestMonitor does the same.
• FeatureFactory.create(log:) is now async throws -> FT (non-optional). Factories throw on backend errors; DDTestMonitor runs them through a single runFactory(_:errorKind:) helper that maps the throw to LibraryConfigurationErrors.
• TestOptimizationApi (and its Settings/KnownTests/Git/TIA/TestManagement/Spans/Logs/Telemetry sub-APIs), APICallError, and TestOptimizationApiService are now public. The SDK builds the service once and stores it on DDTracer.api (non-optional); the exporter no longer exposes the API.
• LibraryConfigurationCommunicationError moved from EventsExporter into the main SDK (internal). The corresponding tests moved with it; Tests/EventsExporter/LibraryConfigurationErrorsTests.swift keeps only the HTTPClient.RequestError description tests.
• EventsExporter is back to being a pure spans/logs/coverage pipeline: removed tracerSettings / skippableTests / knownTests / testManagementTests / searchCommits / uploadPackFiles helpers, the endpointURLs rollup, the api property, and the identity fields from ExporterConfiguration (which now carries only environment, metadata, performancePreset, and logger).
• CodeCoverageProvider.init is throws instead of init?; Logger.measure overloads use typed throws (throws(E)).

Concurrency: closure-scoped writable file

The upload worker reads-and-deletes files on its own queue. Under the
test .readAllFiles preset (minFileAgeForRead == -1, every write rolls
over to a new file) it used to be able to read a freshly-created file
before the writer had appended its bytes — and delete it. The writer's
later append would either lose the value or, after the user's optimisation
that runs the purge step outside the lock, the purge step itself would
delete the file the writer was about to use.

FilesOrchestrator now exposes a closure-scoped writer:

func withWritableFile<T>(writeSize: UInt64,
                         _ body: (WritableFile, _ isNew: Bool) throws -> T) throws -> T

While body runs, the chosen file is "claimed" — the reader's
getReadableFile / getAllReadableFiles filter it out. All mutable
state lives on a private State struct held inside Synced<State>, so
state-touching helpers are reachable only via Synced.use / Synced.update
— the lock is enforced by construction.

A few subtleties that matter:

• Active writes are tracked by file name (Set<String>), not URL.
  Directory.createFile(...) and FileManager.contentsOfDirectory(at:)
  can return URLs that differ on macOS by /var vs /private/var
  canonicalisation, so Set<URL>.contains(...) is unreliable.
• File names use millisecond-resolution timestamps. Two writes that
  land in the same millisecond would collide on the path, and
  FileManager.createFile(atPath:contents:attributes:) silently
  overwrites an existing file. The orchestrator bumps the timestamp
  until the name is unused.
• The retry-write fix in FileWriter was reverted: with proper
  synchronisation, write retries aren't needed.

Test plan

• xcodebuild -scheme EventsExporter -sdk macosx -destination 'platform=macOS,arch=arm64' test — 91 tests pass (10/10 consecutive runs)
• xcodebuild -scheme DatadogSDKTesting -sdk macosx -destination 'platform=macOS,arch=arm64' test — 373 tests pass
• iOS Simulator build of DatadogSDKTesting succeeds
• Run integration tests in CI

🤖 Generated with Claude Code