From 55c2300e41f80086d6ee29c79597d12361464f55 Mon Sep 17 00:00:00 2001
From: Brandon Williams <mbrandonw@hey.com>
Date: Fri, 22 Aug 2025 10:53:20 -0500
Subject: [PATCH] Better way to detect cancellation.

---
 Sources/ComposableArchitecture/Effect.swift   |  2 ++
 .../EffectCancellationTests.swift             | 22 +++++++++++++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/Sources/ComposableArchitecture/Effect.swift b/Sources/ComposableArchitecture/Effect.swift
index 52f84c5bdee5..965565d50a14 100644
--- a/Sources/ComposableArchitecture/Effect.swift
+++ b/Sources/ComposableArchitecture/Effect.swift
@@ -102,6 +102,8 @@ extension Effect {
             } catch is CancellationError {
               return
             } catch {
+              guard !Task.isCancelled
+              else { return }
               guard let handler else {
                 reportIssue(
                   """
diff --git a/Tests/ComposableArchitectureTests/EffectCancellationTests.swift b/Tests/ComposableArchitectureTests/EffectCancellationTests.swift
index 4f33cb139899..7fe5fd49bb09 100644
--- a/Tests/ComposableArchitectureTests/EffectCancellationTests.swift
+++ b/Tests/ComposableArchitectureTests/EffectCancellationTests.swift
@@ -285,6 +285,22 @@ final class EffectCancellationTests: BaseTCATestCase {
     }
     XCTAssertEqual(output, [1, 2])
   }
+
+  @available(iOS 15.0, *)
+  func testCancellationWithoutThrowingCancellationError() async throws {
+    let effect = Effect<Void>.run { send in
+      let session = URLSession(configuration: .ephemeral)
+      let request = URLRequest(url: URL(string: "http://ipv4.download.thinkbroadband.com/1GB.zip")!)
+      let (data, response) = try await session.data(for: request, delegate: nil)
+      _ = (data, response)
+    }
+    .cancellable(id: 1)
+    Task {
+      for await _ in effect.actions {}
+    }
+    try await Task.sleep(nanoseconds: 10_000_000)
+    Task.cancel(id: 1)
+  }
 }
 
 #if DEBUG
@@ -350,7 +366,8 @@ final class EffectCancellationTests: BaseTCATestCase {
             .publisher {
               Just(idx)
                 .delay(
-                  for: .milliseconds(Int.random(in: 1...100)), scheduler: queues.randomElement()!
+                  for: .milliseconds(Int.random(in: 1...100)),
+                  scheduler: queues.randomElement()!
                 )
             }
             .cancellable(id: id),
@@ -358,7 +375,8 @@ final class EffectCancellationTests: BaseTCATestCase {
             .publisher {
               Empty()
                 .delay(
-                  for: .milliseconds(Int.random(in: 1...100)), scheduler: queues.randomElement()!
+                  for: .milliseconds(Int.random(in: 1...100)),
+                  scheduler: queues.randomElement()!
                 )
                 .handleEvents(receiveCompletion: { _ in Task.cancel(id: id) })
             }