Fix for async closure (pointfreeco#25)

* Fix action closures in async contexts.

* more tests

* utf8

* fix for implicit

Author: mbrandonw

Sources/Perception/PerceptionRegistrar.swift

@@ -234,6 +234,7 @@ extension PerceptionRegistrar: Hashable {
           guard
             mangledSymbol.isMangledViewBodyGetter,
             let demangled = String(Substring(mangledSymbol)).demangled,
+            !demangled.isSuspendingClosure,
             !demangled.isActionClosure
           else {
             continue
@@ -247,6 +248,24 @@ extension PerceptionRegistrar: Hashable {
   }
 
   extension String {
+    fileprivate var isSuspendingClosure: Bool {
+      let fragment = self.utf8.drop(while: { $0 != .init(ascii: ")") }).dropFirst()
+      return fragment.starts(
+        with: " suspend resume partial function for closure".utf8
+      )
+      || fragment.starts(
+        with: " suspend resume partial function for implicit closure".utf8
+      )
+      || fragment.starts(
+        with: " await resume partial function for partial apply forwarder for closure".utf8
+      )
+      || fragment.starts(
+        with: " await resume partial function for partial apply forwarder for implicit closure".utf8
+      )
+      || fragment.starts(
+        with: " await resume partial function for implicit closure".utf8
+      )
+    }
     fileprivate var isActionClosure: Bool {
       var view = self[...].utf8
       guard

Tests/PerceptionTests/RuntimeWarningTests.swift

@@ -450,6 +450,55 @@
       self.render(FeatureView())
     }
 
+    func testAccessInOnAppearWithAsyncTask() async throws {
+      @MainActor
+      struct FeatureView: View {
+        let model = Model()
+        var body: some View {
+          Text("Hi")
+            .onAppear {
+              Task { @MainActor in _ = model.count }
+            }
+        }
+      }
+      self.render(FeatureView())
+      try await Task.sleep(for: .milliseconds(100))
+    }
+
+    func testAccessInOnAppearWithAsyncTask_Implicit() async throws {
+      @MainActor
+      struct FeatureView: View {
+        let model = Model()
+        var body: some View {
+          Text("Hi")
+            .onAppear {
+              Task(operation: self.perform)
+            }
+        }
+        @Sendable
+        func perform() async {
+          _ = model.count
+        }
+      }
+      self.render(FeatureView())
+      try await Task.sleep(for: .milliseconds(100))
+    }
+
+    func testAccessInTask() async throws {
+      @MainActor
+      struct FeatureView: View {
+        let model = Model()
+        var body: some View {
+          Text("Hi")
+            .task { @MainActor in
+              _ = model.count
+            }
+        }
+      }
+      self.render(FeatureView())
+      try await Task.sleep(for: .milliseconds(100))
+    }
+
     private func render(_ view: some View) {
       let image = ImageRenderer(content: view).cgImage
       _ = image