From 9ffb95efef238db36eeafe463ace4d0113c52e20 Mon Sep 17 00:00:00 2001
From: Konrad `ktoso` Malawski <konrad_malawski@apple.com>
Date: Thu, 1 Feb 2024 10:57:10 +0900
Subject: [PATCH 1/2] [PATCH] [bug] Fix ignored `at` argument in two instances
 of  `withSpan`

In two cases, the signature for `withSpan` included the `at` parameter
to override the starting timestamp on the span, but it was being ignored
and `DefaultTracerClock.now` was being used instead.
---
 Sources/Tracing/Tracer.swift | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sources/Tracing/Tracer.swift b/Sources/Tracing/Tracer.swift
index 4413f6c..5d944f6 100644
--- a/Sources/Tracing/Tracer.swift
+++ b/Sources/Tracing/Tracer.swift
@@ -195,7 +195,7 @@ public func withSpan<T, Instant: TracerInstant>(
 ) rethrows -> T {
     try InstrumentationSystem.legacyTracer.withAnySpan(
         operationName,
-        at: DefaultTracerClock.now,
+        at: instant(),
         context: context(),
         ofKind: kind,
         function: function,
@@ -339,7 +339,7 @@ public func withSpan<T, Instant: TracerInstant>(
 ) async rethrows -> T {
     try await InstrumentationSystem.legacyTracer.withAnySpan(
         operationName,
-        at: DefaultTracerClock.now,
+        at: instant(),
         context: context(),
         ofKind: kind,
         function: function,

From 960a14eb9836c2bae4ded1253aa55cb29ad40669 Mon Sep 17 00:00:00 2001
From: Konrad `ktoso` Malawski <konrad_malawski@apple.com>
Date: Thu, 1 Feb 2024 11:06:16 +0900
Subject: [PATCH 2/2] add test

---
 Tests/TracingTests/TracerTests.swift | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Tests/TracingTests/TracerTests.swift b/Tests/TracingTests/TracerTests.swift
index 5f0b556..17a2aab 100644
--- a/Tests/TracingTests/TracerTests.swift
+++ b/Tests/TracingTests/TracerTests.swift
@@ -369,6 +369,22 @@ final class TracerTests: XCTestCase {
         tracer.withAnySpan("", context: .topLevel) { _ in }
     }
 
+    func testWithSpanShouldNotMissPropagatingInstant() {
+        let tracer = TestTracer()
+        InstrumentationSystem.bootstrapInternal(tracer)
+        defer {
+            InstrumentationSystem.bootstrapInternal(nil)
+        }
+
+        let clock = DefaultTracerClock()
+
+        let instant = clock.now
+        withSpan("span", at: instant) { _ in }
+
+        let span = tracer.spans.first!
+        XCTAssertEqual(span.startTimestampNanosSinceEpoch, instant.nanosecondsSinceEpoch)
+    }
+
     #if swift(>=5.7.0)
 //    @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
     /// Helper method to execute async operations until we can use async tests (currently incompatible with the generated LinuxMain file).