OpenSwiftUIProject · Kyle-Ye · Nov 23, 2025 · Nov 23, 2025
diff --git a/Sources/OpenSwiftUI/App/FinishLaunchTestAction.swift b/Sources/OpenSwiftUI/App/FinishLaunchTestAction.swift
@@ -17,7 +17,7 @@ struct FinishLaunchTestAction {
         #if os(iOS) || os(visionOS)
         UIApplication.shared.finishedTest(UIApplication.shared._launchTestName())
         #else
-        preconditionFailure("Unimplemented for other platform")
+        _openSwiftUIPlatformUnimplementedWarning()
         #endif
     }
 }

diff --git a/Sources/OpenSwiftUI/Integration/Representable/Platform/PlatformViewRepresentable.swift b/Sources/OpenSwiftUI/Integration/Representable/Platform/PlatformViewRepresentable.swift
@@ -621,11 +621,11 @@ struct PlatformArchivedDisplayList<Content>: Rule where Content: PlatformViewRep
         }
 
         func makePlatformView() -> AnyObject? {
-            preconditionFailure("")
+            _openSwiftUIUnreachableCode()
         }
 
         func updatePlatformView(_ view: inout AnyObject) {
-            preconditionFailure("")
+            _openSwiftUIUnreachableCode()
         }
     }
 }

diff --git a/Sources/OpenSwiftUI/View/Control/Link/OpenURLActionKey.swift b/Sources/OpenSwiftUI/View/Control/Link/OpenURLActionKey.swift
@@ -26,7 +26,7 @@ struct OpenURLActionKey: EnvironmentKey {
                 completion(error != nil)
             }
             #else
-            preconditionFailure("Unimplemented")
+            _openSwiftUIPlatformUnimplementedWarning()
             #endif
         },
         isDefault: true
@@ -51,7 +51,7 @@ struct OpenSensitiveURLActionKey: EnvironmentKey {
             }
             workspace.open(url, configuration: config, completionHandler: completion)
             #else
-            preconditionFailure("Unimplemented")
+            _openSwiftUIPlatformUnimplementedWarning()
             #endif
         },
         isDefault: true

diff --git a/Sources/OpenSwiftUICore/Data/DynamicProperty/DynamicProperty.swift b/Sources/OpenSwiftUICore/Data/DynamicProperty/DynamicProperty.swift
@@ -324,9 +324,10 @@ extension BodyAccessor {
         inputs: inout _GraphInputs,
         fields: DynamicPropertyCache.Fields
     ) -> (_GraphValue<Body>, _DynamicPropertyBuffer?) {
-        guard Body.self != Never.self else {
-            preconditionFailure("\(Container.self) may not have Body == Never")
-        }
+        precondition(
+            Body.self != Never.self,
+            "\(Container.self) may not have Body == Never"
+        )
         return withUnsafePointer(to: inputs) { pointer in
             func project<Flags>(flags _: Flags.Type) -> (_GraphValue<Body>, _DynamicPropertyBuffer?) where Flags: RuleThreadFlags {
                 let buffer = _DynamicPropertyBuffer(

diff --git a/Sources/OpenSwiftUICore/Data/Protobuf/ProtobufDecoder.swift b/Sources/OpenSwiftUICore/Data/Protobuf/ProtobufDecoder.swift
@@ -473,7 +473,7 @@ extension ProtobufDecoder {
     /// - Returns: The decodable value resulting from the plist data.
     func value<T>(fromBinaryPlist data: Data, type: T.Type = T.self) throws -> T where T: Decodable {
         #if os(WASI)
-        preconditionFailure("PropertyListDecoder is not avaiable on WASI")
+        _openSwiftUIPlatformUnimplementedFailure()
         #else
         let decoder = PropertyListDecoder()
         decoder.userInfo = userInfo

diff --git a/Sources/OpenSwiftUICore/Data/Protobuf/ProtobufEncoder.swift b/Sources/OpenSwiftUICore/Data/Protobuf/ProtobufEncoder.swift
@@ -415,7 +415,7 @@ extension ProtobufEncoder {
     /// - Returns: The encoded binary plist data.
     func binaryPlistData<T>(for value: T) throws -> Data where T: Encodable {
         #if os(WASI)
-        preconditionFailure("PropertyListEncoder is not avaiable on WASI")
+        _openSwiftUIPlatformUnimplementedFailure()
         #else
         let encoder = PropertyListEncoder()
         encoder.outputFormat = .binary

diff --git a/Sources/OpenSwiftUICore/Data/Update.swift b/Sources/OpenSwiftUICore/Data/Update.swift
@@ -60,9 +60,10 @@ package enum Update {
         guard lockAssertionsAreEnabled else {
             return
         }
-        guard isOwner else {
-            preconditionFailure("OpenSwiftUI is active without having taken its own lock - missing Update.ensure()?")
-        }
+        precondition(
+            isOwner,
+            "OpenSwiftUI is active without having taken its own lock - missing Update.ensure()?"
+        )
     }
 
     package static func begin() {
@@ -184,10 +185,10 @@ package enum Update {
                     }
                     for action in actions {
                         action()
-                        let newDepth = depth
-                        guard newDepth == oldDepth else {
-                            preconditionFailure("Action caused unbalanced updates.")
-                        }
+                        precondition(
+                            depth == oldDepth,
+                            "Action caused unbalanced updates."
+                        )
                     }
                 }
             }

diff --git a/Sources/OpenSwiftUICore/Layout/Dynamic/DynamicContainer.swift b/Sources/OpenSwiftUICore/Layout/Dynamic/DynamicContainer.swift
@@ -629,7 +629,7 @@ struct DynamicContainerInfo<Adapter>: StatefulRule, AsyncAttribute, ObservedAttr
         }
         switch phase {
         case .willAppear:
-            preconditionFailure("")
+            _openSwiftUIUnreachableCode()
         case .identity:
             guard !disableTransitions, info.items[index].needsTransitions else {
                 eraseItem(at: index)
@@ -696,7 +696,7 @@ struct DynamicContainerInfo<Adapter>: StatefulRule, AsyncAttribute, ObservedAttr
         let phase = info.items[index].phase
         switch phase {
         case .willAppear, nil:
-            preconditionFailure("")
+            _openSwiftUIUnreachableCode()
         case .identity:
             break
         case .didDisappear:

diff --git a/Sources/OpenSwiftUICore/Layout/Geometry/LayoutTraits.swift b/Sources/OpenSwiftUICore/Layout/Geometry/LayoutTraits.swift
@@ -59,14 +59,11 @@ public struct _LayoutTraits: Equatable {
         }
 
         private func _checkInvariant() {
-            guard min >= 0,
-                  min.isFinite,
-                  ideal < .infinity,
-                  min <= ideal,
-                  ideal <= max
-            else {
-                preconditionFailure("malformed dimension \(self)")
-            }
+            precondition(
+                min >= 0 && min.isFinite && ideal < .infinity &&
+                min <= ideal && ideal <= max,
+                "malformed dimension \(self)"
+            )
         }
     }
 

diff --git a/Sources/OpenSwiftUICore/Layout/Layout.swift b/Sources/OpenSwiftUICore/Layout/Layout.swift
@@ -1700,9 +1700,10 @@ public struct LayoutSubview: Equatable {
 
     package func place(at position: CGPoint, anchor: UnitPoint = .topLeading, dimensions: ViewDimensions) {
         let origin = CGRect(position: position, size: dimensions.size.value, anchor: anchor).origin
-        guard !origin.isNaN else {
-            preconditionFailure("view origin is invalid: \(position), \(anchor), \(dimensions.size.value)")
-        }
+        precondition(
+            !origin.isNaN,
+            "view origin is invalid: \(position), \(anchor), \(dimensions.size.value)"
+        )
         place(in: ViewGeometry(origin: origin, dimensions: dimensions))
     }
 

diff --git a/Sources/OpenSwiftUICore/Layout/LayoutComputer/LayoutComputer.swift b/Sources/OpenSwiftUICore/Layout/LayoutComputer/LayoutComputer.swift
@@ -101,9 +101,7 @@ private class LayoutEngineBox<Engine>: AnyLayoutEngineBox where Engine: LayoutEn
     }
 
     override func mutateEngine<E, R>(as type: E.Type, do body: (inout E) -> R) -> R where E: LayoutEngine {
-        guard Engine.self == E.self else {
-            preconditionFailure("Mismatched engine type")
-        }
+        precondition(Engine.self == E.self, "Mismatched engine type")
         return withUnsafePointer(to: &engine) { ptr in
             body(&UnsafeMutableRawPointer(mutating: UnsafeRawPointer(ptr)).assumingMemoryBound(to: E.self).pointee)
         }

diff --git a/Sources/OpenSwiftUICore/Layout/View/ViewTransform.swift b/Sources/OpenSwiftUICore/Layout/View/ViewTransform.swift
@@ -70,7 +70,7 @@ public struct ViewTransform: Equatable, CustomStringConvertible {
                         rect = rect.applying(transform)
                     }
                     #else
-                    preconditionFailure("CGAffineTransform+applying is not available on this platform")
+                    _openSwiftUIPlatformUnimplementedWarning()
                     #endif
                 case .projectionTransform:
                     rect = nil
@@ -100,7 +100,7 @@ public struct ViewTransform: Equatable, CustomStringConvertible {
                         geometry.containerSize = geometry.containerSize.applying(transform)
                     }
                     #else
-                    preconditionFailure("CGAffineTransform+applying is not available on this platform")
+                    _openSwiftUIPlatformUnimplementedWarning()
                     #endif
                 case .projectionTransform:
                     geometry = nil
@@ -684,7 +684,7 @@ extension CGPoint: ApplyViewTransform, ViewTransformable {
                     self = applying(matrix)
                 }
                 #else
-                preconditionFailure("CGAffineTransform+applying is not available on this platform")
+                _openSwiftUIPlatformUnimplementedWarning()
                 #endif
             case let .projectionTransform(matrix, inverse):
                 self = inverse ? unapplying(matrix) : applying(matrix)
@@ -712,7 +712,7 @@ extension [CGPoint]: ApplyViewTransform, ViewTransformable {
                 let tranform = inverse ? matrix.inverted() : matrix
                 self = map { $0.applying(tranform) }
                 #else
-                preconditionFailure("CGAffineTransform+applying is not available on this platform")
+                _openSwiftUIPlatformUnimplementedWarning()
                 #endif
             case let .projectionTransform(matrix, inverse):
                 apply(matrix, inverse: inverse)

diff --git a/Sources/OpenSwiftUICore/Log/Logging.swift b/Sources/OpenSwiftUICore/Log/Logging.swift
@@ -255,6 +255,11 @@ extension os.OSLog {
 
 // MARK: - OpenSwiftUI addition: abstract and stub call
 
+@_transparent
+package func _openSwiftUIUnreachableCode(_ function: String = #function, file: StaticString = #fileID, line: UInt = #line) -> Never {
+    preconditionFailure("", file: file, line: line)
+}
+
 @_transparent
 package func _openSwiftUIBaseClassAbstractMethod(_ function: String = #function, file: StaticString = #fileID, line: UInt = #line) -> Never {
     preconditionFailure("", file: file, line: line)
@@ -269,12 +274,12 @@ package func _openSwiftUIEmptyStub(_ function: String = #function, file: StaticS
 
 @_transparent
 package func _openSwiftUIUnimplementedFailure(_ function: String = #function, file: StaticString = #fileID, line: UInt = #line) -> Never {
-    preconditionFailure("TODO", file: file, line: line)
+    preconditionFailure("Unimplemented yet", file: file, line: line)
 }
 
 @_transparent
 package func _openSwiftUIPlatformUnimplementedFailure(_ function: String = #function, file: StaticString = #fileID, line: UInt = #line) -> Never {
-    preconditionFailure("TODO", file: file, line: line)
+    preconditionFailure("Unimplemented for this platform yet", file: file, line: line)
 }
 
 @_transparent

diff --git a/Sources/OpenSwiftUICore/Modifier/CustomViewModifier.swift b/Sources/OpenSwiftUICore/Modifier/CustomViewModifier.swift
@@ -161,9 +161,10 @@ extension ViewModifier {
         inputs: inout _GraphInputs,
         fields: DynamicPropertyCache.Fields
     ) -> (_GraphValue<Body>, _DynamicPropertyBuffer?) {
-        guard Metadata(Self.self).isValueType else {
-            preconditionFailure("view modifiers must be value types: \(Self.self)")
-        }
+        precondition(
+            Metadata(Self.self).isValueType,
+            "view modifiers must be value types: \(Self.self)"
+        )
         let accessor = ModifierBodyAccessor<Self>()
         return accessor.makeBody(container: modifier, inputs: &inputs, fields: fields)
     }

diff --git a/Sources/OpenSwiftUICore/Modifier/ViewModifier/EnvironmentalModifier.swift b/Sources/OpenSwiftUICore/Modifier/ViewModifier/EnvironmentalModifier.swift
@@ -74,9 +74,10 @@ extension EnvironmentalModifier {
         inputs: inout _GraphInputs,
         fields: DynamicPropertyCache.Fields
     ) -> (_GraphValue<ResolvedModifier>, _DynamicPropertyBuffer?) {
-        guard Metadata(Self.self).isValueType else {
-            preconditionFailure("Environmental modifiers must be value types: \(Self.self)")
-        }
+        precondition(
+            Metadata(Self.self).isValueType,
+            "Environmental modifiers must be value types: \(Self.self)"
+        )
         var fields = fields
         if !fields.behaviors.contains(.requiresMainThread), !_requiresMainThread {
             fields.behaviors.formUnion(

diff --git a/Sources/OpenSwiftUICore/Render/DisplayList/DisplayListViewPlatform.swift b/Sources/OpenSwiftUICore/Render/DisplayList/DisplayListViewPlatform.swift
@@ -115,7 +115,8 @@ extension DisplayList.GraphicsRenderer {
             layer.bounds = CGRect(origin: .zero, size: size)
             layer.layoutIfNeeded()
         }
-        preconditionFailure("Blocked by GraphicsContext")
+        // TODO: Blocked by GraphicsContext
+        _openSwiftUIUnimplementedFailure()
         // ctx.drawLayer
     }
     #endif

diff --git a/Sources/OpenSwiftUICore/Util/ThreadUtils.swift b/Sources/OpenSwiftUICore/Util/ThreadUtils.swift
@@ -29,7 +29,7 @@ final package class ThreadSpecific<T> {
     }
 
     deinit {
-        preconditionFailure("\(Self.self).deinit is unsafe and would leak", file: #file, line: #line)
+        preconditionFailure("\(Self.self).deinit is unsafe and would leak")
     }
 
     private final var box: UnsafeMutablePointer<Any> {

diff --git a/Sources/OpenSwiftUICore/View/CustomView.swift b/Sources/OpenSwiftUICore/View/CustomView.swift
@@ -52,9 +52,10 @@ extension View {
         inputs: inout _GraphInputs,
         fields: DynamicPropertyCache.Fields
     ) -> (_GraphValue<Body>, _DynamicPropertyBuffer?) {
-        guard Metadata(Self.self).isValueType else {
-            preconditionFailure("views must be value types (either a struct or an enum); \(Self.self) is a class.")
-        }
+        precondition(
+            Metadata(Self.self).isValueType,
+            "views must be value types (either a struct or an enum); \(Self.self) is a class."
+        )
         let accessor = ViewBodyAccessor<Self>()
         return accessor.makeBody(container: view, inputs: &inputs, fields: fields)
     }

diff --git a/Sources/OpenSwiftUICore/View/Graph/ViewGraph.swift b/Sources/OpenSwiftUICore/View/Graph/ViewGraph.swift
@@ -468,9 +468,10 @@ extension ViewGraph {
 //package typealias SizeThatFitsObservers = ViewGraphGeometryObservers<SizeThatFitsMeasurer>
 extension ViewGraph {
     private var layoutComputer: LayoutComputer? {
-        guard requestedOutputs.contains(.layout) else {
-            preconditionFailure("Cannot fetch layout computer without layout output")
-        }
+        precondition(
+            requestedOutputs.contains(.layout),
+            "Cannot fetch layout computer without layout output"
+        )
         instantiateIfNeeded()
         return rootLayoutComputer
     }

diff --git a/Sources/OpenSwiftUICore/View/Graph/ViewRendererHost.swift b/Sources/OpenSwiftUICore/View/Graph/ViewRendererHost.swift
@@ -359,9 +359,10 @@ extension ViewRendererHost {
     }
 
     package func advanceTimeForTest(interval: Double) {
-        guard interval >= 0 else {
-            preconditionFailure("Test render timestamps must monotonically increase.")
-        }
+        precondition(
+            interval >= 0,
+            "Test render timestamps must monotonically increase."
+        )
         let advancedTime = currentTimestamp + interval
         currentTimestamp = advancedTime == currentTimestamp ? Time(seconds: nextafter(advancedTime.seconds, Double.infinity)) : advancedTime
     }
@@ -432,9 +433,10 @@ extension ViewRendererHost {
         }
         update()
         for host in enclosingHosts {
-            guard host.externalUpdateCount >= 1 else {
-                preconditionFailure("Unbalanced will/did update functions.")
-            }
+            precondition(
+                host.externalUpdateCount >= 1,
+                "Unbalanced will/did update functions."
+            )
             host.externalUpdateCount -= 1
         }
     }

diff --git a/Sources/OpenSwiftUICore/View/Style/ViewStyle.swift b/Sources/OpenSwiftUICore/View/Style/ViewStyle.swift
@@ -278,9 +278,10 @@ private struct StyleModifierType<M>: AnyStyleModifierType where M: StyleModifier
         fields: DynamicPropertyCache.Fields
     ) -> (_GraphValue<M.StyleBody>, _DynamicPropertyBuffer?) where V: StyleableView {
         if Semantics.ViewStylesMustBeValueTypes.isEnabled {
-            guard Metadata(M.Style.self).isValueType else {
-                preconditionFailure("styles must be value types (either a struct or an enum); \(M.Style.self) is a class.")
-            }
+            precondition(
+                Metadata(M.Style.self).isValueType,
+                "styles must be value types (either a struct or an enum); \(M.Style.self) is a class."
+            )
         }
         let styleModifier = modifier.value.unsafeCast(to: M.self)
         let accessor = StyleBodyAccessor<V, M>(

diff --git a/Sources/OpenSwiftUICore/View/VariadicView/VariadicView.swift b/Sources/OpenSwiftUICore/View/VariadicView/VariadicView.swift
@@ -348,9 +348,10 @@ extension _VariadicView.ViewRoot {
         inputs: inout _GraphInputs,
         fields: DynamicPropertyCache.Fields
     ) -> (_GraphValue<Body>, _DynamicPropertyBuffer?) {
-        guard Metadata(Self.self).isValueType else {
-            preconditionFailure("views root must be value types (either a struct or an enum); \(Self.self) is a class.")
-        }
+        precondition(
+            Metadata(Self.self).isValueType,
+            "views root must be value types (either a struct or an enum); \(Self.self) is a class."
+        )
         let accessor = ViewRootBodyAccessor<Self>(list: list, contentSubgraph: .current!)
         return accessor.makeBody(container: root, inputs: &inputs, fields: fields)
     }