Add support for platforms without Foundation

Author: x-sheep

.spi.yml

@@ -2,3 +2,5 @@ version: 1
 builder:
   configs:
     - documentation_targets: [PropertyBased]
+      custom_documentation_parameters:
+      - --enable-experimental-overloaded-symbol-presentation

Sources/PropertyBased/FixedSeedTrait.swift

@@ -12,8 +12,8 @@ import Testing
 ///
 /// Use ``fixedSeed(_:sourceLocation:)`` to construct an instance of this trait.
 public struct FixedSeedTrait: TestTrait, TestScoping {
-    init(_ seed: String, _ sourceLocation: SourceLocation) {
-        rng = Xoshiro(seed: seed)
+    init(_ rng: Xoshiro?, _ sourceLocation: SourceLocation) {
+        self.rng = rng
         self.sourceLocation = sourceLocation
     }
 
@@ -58,7 +58,34 @@ extension Trait where Self == FixedSeedTrait {
     ///   - sourceLocation: The source location of the trait.
     ///
     /// - Returns: An instance of ``FixedSeedTrait``.
+#if canImport(Foundation)
     public static func fixedSeed(_ seed: StaticString, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
-        return Self(seed.description, sourceLocation)
+        let rng = Xoshiro(seed: seed.description)
+        return Self(rng, sourceLocation)
+    }
+#else
+    @available(*, unavailable, message: "Base64-encoded seeds aren't supported on platforms without Foundation.\nUse the fixedSeed() overload that takes UInt64's instead.")
+    public static func fixedSeed(_ seed: StaticString, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        fatalError("Base64 is not supported")
+    }
+#endif
+    
+    /// Override the seed used by all property checks within this Test.
+    ///
+    /// If one of your property checks fails intermittently, apply this trait to reliably reproduce the issue.
+    ///
+    /// > Important: Do not commit usages of this trait into version control. Applying this trait will always report an issue regardless of the existence of any failures within the test.
+    ///
+    /// - Parameters:
+    ///   - s1: The first part of the seed to use.
+    ///   - s2: The second part of the seed.
+    ///   - s3: The third part of the seed.
+    ///   - s4: The fourth part of the seed.
+    ///   - sourceLocation: The source location of the trait.
+    ///
+    /// - Returns: An instance of ``FixedSeedTrait``.
+    public static func fixedSeed(_ s1: UInt64, _ s2: UInt64, _ s3: UInt64, _ s4: UInt64, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        let rng = Xoshiro(seed: (s1, s2, s3, s4))
+        return Self(rng, sourceLocation)
     }
 }

Sources/PropertyBased/PropertyCheck.swift

@@ -93,7 +93,7 @@ public func propertyCheck<each Value>(isolation: isolated (any Actor)? = #isolat
         }
 
         if foundIssues > 0 {
-            let seed = rngCopy.currentSeed
+            let seed = rngCopy.traitHint
 
             var paramLabels: [String] = []
             for gen in repeat each input {
@@ -105,7 +105,7 @@ public func propertyCheck<each Value>(isolation: isolated (any Actor)? = #isolat
             "Failure occured with inputs (\(paramLabels.joined(separator: ", ")))."
 
             if fixedRng == nil {
-                Issue.record("\(inputLabel)\n\nAdd `.fixedSeed(\"\(seed)\")` to the Test to reproduce this issue.", sourceLocation: sourceLocation)
+                Issue.record("\(inputLabel)\n\nAdd `.fixedSeed\(seed)` to the Test to reproduce this issue.", sourceLocation: sourceLocation)
             } else {
                 Issue.record("\(inputLabel)", sourceLocation: sourceLocation)
             }

Sources/PropertyBased/SeededRandomNumberGenerator.swift

@@ -13,7 +13,7 @@
 public protocol SeededRandomNumberGenerator: RandomNumberGenerator, Hashable, Sendable {
 
     /// The type to use as the seed.
-    associatedtype Seed: Hashable & Codable
+    associatedtype Seed: Sendable
 
     /// The current seed of the generator.
     ///
@@ -25,7 +25,7 @@ public protocol SeededRandomNumberGenerator: RandomNumberGenerator, Hashable, Se
     ///
     /// If the seed is invalid or incomplete, this initializer returns `nil`.
     /// - Parameter seed: The seed to use.
-    init?(seed: String)
+    init?(seed: Seed)
 
     /// Create an instance of this generator with a seed provided by a high-quality random source.
     init()

Sources/PropertyBased/Xoshiro+SeededRandomNumberGenerator.swift

@@ -6,7 +6,6 @@
 //
 
 import Gen
-import Foundation
 
 extension Xoshiro: @retroactive @unchecked Sendable {}
 extension Xoshiro: @retroactive Hashable {
@@ -22,6 +21,15 @@ extension Xoshiro: @retroactive Hashable {
     }
 }
 
+extension Xoshiro {
+    public init(seed: (UInt64, UInt64, UInt64, UInt64)) {
+        self.init(state: seed)
+    }
+}
+
+#if canImport(Foundation)
+import Foundation
+
 extension Xoshiro: SeededRandomNumberGenerator {
     public typealias Seed = String
 
@@ -43,4 +51,16 @@ extension Xoshiro: SeededRandomNumberGenerator {
         let data = bytes.withUnsafeBufferPointer { Data(buffer: $0) }
         return data.base64EncodedString()
     }
+    
+    var traitHint: String {
+        "(\"\(currentSeed)\")"
+    }
+}
+#else
+extension Xoshiro: SeededRandomNumberGenerator {
+    public typealias Seed = (UInt64, UInt64, UInt64, UInt64)
+    
+    public var currentSeed: Seed { currentState }
+    var traitHint: String { "\(currentState)" }
 }
+#endif