Add RuntimeWarnings.swift from The Composable Architecture

https://github.com/pointfreeco/swift-composable-architecture/blob/399bc83dcfc7bdcee99f7f6cc0a687ca29e8494b/Sources/ComposableArchitecture/Internal/RuntimeWarnings.swift

Author: ole

DebugLayout/Sources/DebugLayout/RuntimeWarnings.swift

@@ -0,0 +1,58 @@
+// Source: Point-Free, Swift Composable Architecture, RuntimeWarnings.swift
+// https://github.com/pointfreeco/swift-composable-architecture/blob/399bc83dcfc7bdcee99f7f6cc0a687ca29e8494b/Sources/ComposableArchitecture/Internal/RuntimeWarnings.swift
+//
+// Based on: Point-Free, Unobtrusive runtime warnings for libraries (2022-01-03)
+// https://www.pointfree.co/blog/posts/70-unobtrusive-runtime-warnings-for-libraries
+
+#if DEBUG
+  import os
+  import XCTestDynamicOverlay
+
+  // NB: Xcode runtime warnings offer a much better experience than traditional assertions and
+  //     breakpoints, but Apple provides no means of creating custom runtime warnings ourselves.
+  //     To work around this, we hook into SwiftUI's runtime issue delivery mechanism, instead.
+  //
+  // Feedback filed: https://gist.github.com/stephencelis/a8d06383ed6ccde3e5ef5d1b3ad52bbc
+  private let rw = (
+    dso: { () -> UnsafeMutableRawPointer in
+      let count = _dyld_image_count()
+      for i in 0..<count {
+        if let name = _dyld_get_image_name(i) {
+          let swiftString = String(cString: name)
+          if swiftString.hasSuffix("/SwiftUI") {
+            if let header = _dyld_get_image_header(i) {
+              return UnsafeMutableRawPointer(mutating: UnsafeRawPointer(header))
+            }
+          }
+        }
+      }
+      return UnsafeMutableRawPointer(mutating: #dsohandle)
+    }(),
+    log: OSLog(subsystem: "com.apple.runtime-issues", category: "ComposableArchitecture")
+  )
+#endif
+
+@_transparent
+@inline(__always)
+func runtimeWarning(
+  _ message: @autoclosure () -> StaticString,
+  _ args: @autoclosure () -> [CVarArg] = [],
+  file: StaticString? = nil,
+  line: UInt? = nil
+) {
+  #if DEBUG
+    let message = message()
+    if _XCTIsTesting {
+      if let file = file, let line = line {
+        XCTFail(String(format: "\(message)", arguments: args()), file: file, line: line)
+      } else {
+        XCTFail(String(format: "\(message)", arguments: args()))
+      }
+    } else {
+      unsafeBitCast(
+        os_log as (OSLogType, UnsafeRawPointer, OSLog, StaticString, CVarArg...) -> Void,
+        to: ((OSLogType, UnsafeRawPointer, OSLog, StaticString, [CVarArg]) -> Void).self
+      )(.fault, rw.dso, rw.log, message, args())
+    }
+  #endif
+}