Platform truth, no placeholder digests, DocC in target, test layout

.github/workflows/test.yml

@@ -31,6 +31,9 @@ jobs:
 
       - name: Build package
         run: swift build
+
+      - name: Build for iOS Simulator
+        run: xcodebuild build -scheme DesignAlgorithmsKit -destination 'generic/platform=iOS Simulator'
 
       - name: Run tests with code coverage
         run: |

CHANGELOG.md

@@ -7,6 +7,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed (`platform-and-test-hygiene`)
+- Building without CryptoKit is a compile-time error. The non-cryptographic placeholder that `SHA256.hash` returned on such platforms, and the `fatalError` paths in `MD5Strategy`/`SHA1Strategy`, are gone. `SHA256.hash(data:)` delegates to `SHA256Strategy`.
+- Platform claims match the build: macOS 12 and iOS 15 (both built in CI). WASM, tvOS and watchOS are no longer claimed.
+- The DocC catalog lives in the target (`Sources/DesignAlgorithmsKit/DesignAlgorithmsKit.docc`), and its symbol links resolve with no warnings.
+- The gzip/gunzip interoperability tests moved to a separate `DesignAlgorithmsKitIntegrationTests` target (macOS, skipped when the tools are missing).
+- Corrected doc comments for `FilenameTokenizer`, `ObjectFactory` and `HashAlgorithm`.
+
+### Added (`platform-and-test-hygiene`)
+- `HybridEncryption` tests.
+
+### Removed (`platform-and-test-hygiene`)
+- The empty `Algorithms/WASMGuard.swift` and its `exclude` entry.
+- The GitHub Pages publish workflow and script. They needed `swift-docc-plugin`, which this package does not depend on, so they only ever published a static fallback page.
+- The placeholder swift-testing `example()` test.
+
 ### Changed (`fix-ulid-spec-compliance`)
 - **ULID text format:** `ULID.string`/`description` and `ULID(string:)` now follow the ULID specification (2 padding bits at the front, so the first character is `0`-`7`). `ULID(string:)` rejects strings starting above `7`. The 16 bytes are unchanged; only the text differs.
 - **Migration:** strings stored by 1.10.x/1.11.x do not parse the same way. Read them with the new `ULID(legacyString:)` and re-save `string`. Known consumers: RetroboxBBS and RetroServe (TermFoundation).
@@ -49,6 +64,26 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Notes
 - Releases v1.8.0 (FilenameTokenizer, UUIDv5Generator), v1.9.0 (Visitor, Graph, Gzip) and v1.10.0 were tagged without CHANGELOG entries; backfill is tracked in `platform-and-test-hygiene`
 
+## [1.10.0] - 2026-02-04
+
+### Changed
+- `.gitignore` excludes `.build` and other build artifacts.
+
+### Notes
+- A MerkleTree consolidation was merged and reverted before the tag; the public API matches 1.9.0.
+
+## [1.9.0] - 2026-01-02
+
+### Added
+- `Visitor` pattern and `Graph` data structure (#14).
+- `Gzip` in-memory GZIP compression and decompression (#15).
+
+## [1.8.0] - 2025-12-29
+
+### Added
+- `UUIDv5Generator` for name-based (RFC 4122 version 5) UUIDs.
+- `FilenameTokenizer` for splitting file names into words (#13).
+
 ## [1.7.0] - 2025-12-21
 
 ### Added

Package.swift

@@ -14,18 +14,13 @@ let package = Package(
             name: "DesignAlgorithmsKit",
             targets: ["DesignAlgorithmsKit"]),
     ],
-    dependencies: [
-        // No dependencies - keep it simple for WASM compatibility
-    ],
+    // No package dependencies. Apple platforms only (CryptoKit, NSLock).
+    dependencies: [],
     targets: [
         .target(
             name: "DesignAlgorithmsKit",
             dependencies: [],
             path: "Sources/DesignAlgorithmsKit",
-            exclude: [
-                // Exclude hash/crypto types for WASM builds (they use NSLock)
-                "Algorithms/WASMGuard.swift"
-            ],
             linkerSettings: [
                 .linkedLibrary("z")
             ]
@@ -38,5 +33,11 @@ let package = Package(
                 .linkedLibrary("z")
             ]
         ),
+        // Tests that run system tools (gzip/gunzip); macOS only, skipped when the tools are missing.
+        .testTarget(
+            name: "DesignAlgorithmsKitIntegrationTests",
+            dependencies: ["DesignAlgorithmsKit"],
+            path: "Tests/DesignAlgorithmsKitIntegrationTests"
+        ),
     ]
 )

README.md

@@ -29,7 +29,7 @@ One library product and target: **`DesignAlgorithmsKit`** (`Sources/DesignAlgori
 
 ## Platforms
 
-`Package.swift` declares macOS 12 and iOS 15, with swift-tools-version 5.10. The library imports CryptoKit and links the system zlib, so in practice it builds only for Apple platforms. The older WASM, tvOS and watchOS claims are not backed by the build.
+macOS 12 and iOS 15 (swift-tools-version 5.10); CI builds both. The library uses CryptoKit, `NSLock` and the system zlib, so it builds only for Apple platforms; building without CryptoKit fails with a compile-time error instead of producing placeholder digests. tvOS and watchOS are not declared or built.
 
 ## Dependencies
 
@@ -93,16 +93,16 @@ swift test
 ```
 
 - No other packages are needed to build DAK.
-- Current baseline: `swift build` succeeds with two warnings, and `swift test` runs 343 XCTest tests and 1 swift-testing placeholder with 0 failures.
-- `IntegrationCompressionTests` runs `/usr/bin/gzip` and `/usr/bin/gunzip`, so it needs macOS.
+- `swift build` is warning-free. `swift test` runs the unit tests (`DesignAlgorithmsKitTests`, 374 XCTest tests) and the integration tests (`DesignAlgorithmsKitIntegrationTests`), which call `/usr/bin/gzip` and `/usr/bin/gunzip` and are skipped when those tools are missing.
+- CI also builds for the iOS Simulator: `xcodebuild build -scheme DesignAlgorithmsKit -destination 'generic/platform=iOS Simulator'`.
 
 ## Known issues
 
-- Platform claims are broader than tested, `WASMGuard.swift` is dead code, SHA code is duplicated, and the DocC catalog is not attached to the target.
+None known.
 
 ## Documentation
 
-- `Documentation.docc/`: DocC articles. They are not yet attached to the target.
+- `Sources/DesignAlgorithmsKit/DesignAlgorithmsKit.docc/`: DocC catalog. Build it with Xcode's Product > Build Documentation or `xcodebuild docbuild -scheme DesignAlgorithmsKit -destination 'generic/platform=macOS'`.
 - [CHANGELOG.md](CHANGELOG.md), [CONTRIBUTING.md](CONTRIBUTING.md), [SECURITY.md](SECURITY.md), [CODE_OF_CONDUCT.md](CODE_OF_CONDUCT.md).
 
 ## License

Sources/DesignAlgorithmsKit/Algorithms/Compression/Gzip.swift

@@ -39,7 +39,7 @@ public struct Gzip {
     }
 
     /// Decompresses GZIP compressed data.
-    /// - Parameter data: The compressed data (including GZIP header).
+    /// - Parameter input: The compressed data (including GZIP header).
     /// - Returns: The uncompressed data.
     /// - Throws: `Gzip.Error.decompressionFailed`, or `invalidData` for a malformed header or a
     ///   trailer whose CRC-32 or ISIZE does not match the inflated bytes.

Sources/DesignAlgorithmsKit/Algorithms/Hashing/HashAlgorithm.swift

@@ -9,15 +9,15 @@
 
 import Foundation
 
-/// Hash algorithms supported for file and disk image hashing
+/// Hash algorithms for content hashing and checksum validation
 public enum HashAlgorithm: String, CaseIterable, Codable, Sendable {
     /// SHA-256: Recommended default for new hash generation (cryptographically secure)
     case sha256 = "sha256"
 
     /// SHA-1: Legacy support for existing systems (deprecated but collision-resistant)
     case sha1 = "sha1"
 
-    /// MD5: Read-only legacy support for validation against companion files and existing checksums
+    /// MD5: Read-only legacy support for validation against existing checksums
     /// ⚠️ Do not use for new hash generation - use SHA-256 instead
     /// ✅ Supported for: reading companion checksum files (.md5, .md5sum), validating against existing MD5 hashes
     case md5 = "md5"

Sources/DesignAlgorithmsKit/Algorithms/Hashing/HashAlgorithmProtocol.swift

@@ -7,8 +7,8 @@
 
 import Foundation
 
-#if canImport(CryptoKit)
-import CryptoKit
+#if !canImport(CryptoKit)
+#error("DesignAlgorithmsKit needs CryptoKit for its digests; it builds only for Apple platforms.")
 #endif
 
 /// Protocol for hash algorithms
@@ -43,43 +43,11 @@ public extension HashAlgorithmProtocol {
     }
 }
 
-/// SHA-256 hash algorithm
+/// SHA-256 hash algorithm (CryptoKit, through ``SHA256Strategy``)
 public enum SHA256: HashAlgorithmProtocol {
     public static let name = "SHA-256"
 
     public static func hash(data: Data) -> Data {
-        #if canImport(CryptoKit)
-        let digest = CryptoKit.SHA256.hash(data: data)
-        return Data(digest)
-        #else
-        // Fallback implementation
-        // In production, use CommonCrypto or another crypto library
-        return fallbackHash(data: data)
-        #endif
+        SHA256Strategy().compute(data: data)
     }
-
-    #if !canImport(CryptoKit)
-    /// Fallback hash implementation (simple, not cryptographically secure)
-    /// For production use, import CryptoKit or CommonCrypto
-    /// - Note: This path is conditionally compiled and only available when CryptoKit is not available.
-    ///   It cannot be tested in environments where CryptoKit is available (like macOS/iOS test environments).
-    ///   The fallback implementation is intentionally simple and not cryptographically secure.
-    private static func fallbackHash(data: Data) -> Data {
-        var hash = Data(count: 32)
-        data.withUnsafeBytes { dataBytes in
-            hash.withUnsafeMutableBytes { hashBytes in
-                // Simple hash (NOT cryptographically secure)
-                // This is a placeholder - use CryptoKit in production
-                for i in 0..<32 {
-                    var value: UInt8 = 0
-                    for j in 0..<dataBytes.count {
-                        value ^= dataBytes[j] &+ UInt8(i)
-                    }
-                    hashBytes[i] = value
-                }
-            }
-        }
-        return hash
-    }
-    #endif
 }

Sources/DesignAlgorithmsKit/Algorithms/Hashing/Strategies/MD5Strategy.swift

@@ -2,9 +2,7 @@
 // MD5 Hash Strategy
 
 import Foundation
-#if canImport(CryptoKit)
 import CryptoKit
-#endif
 
 /// Strategy for MD5 hashing
 /// Note: MD5 is insecure and should only be used for legacy compatibility
@@ -14,11 +12,7 @@ public struct MD5Strategy: HashStrategy {
     public init() {}
 
     public func compute(data: Data) -> Data {
-        #if canImport(CryptoKit)
         let digest = Insecure.MD5.hash(data: data)
         return Data(digest)
-        #else
-        fatalError("CryptoKit not available for MD5")
-        #endif
     }
 }

Sources/DesignAlgorithmsKit/Algorithms/Hashing/Strategies/SHA1Strategy.swift

@@ -2,9 +2,7 @@
 // SHA-1 Hash Strategy
 
 import Foundation
-#if canImport(CryptoKit)
 import CryptoKit
-#endif
 
 /// Strategy for SHA-1 hashing
 /// Note: SHA-1 is insecure and should only be used for legacy compatibility
@@ -14,11 +12,7 @@ public struct SHA1Strategy: HashStrategy {
     public init() {}
 
     public func compute(data: Data) -> Data {
-        #if canImport(CryptoKit)
         let digest = Insecure.SHA1.hash(data: data)
         return Data(digest)
-        #else
-        fatalError("CryptoKit not available for SHA1")
-        #endif
     }
 }

Sources/DesignAlgorithmsKit/Algorithms/Hashing/Strategies/SHA256Strategy.swift

@@ -2,9 +2,7 @@
 // SHA-256 Hash Strategy
 
 import Foundation
-#if canImport(CryptoKit)
 import CryptoKit
-#endif
 
 /// Strategy for SHA-256 hashing
 public struct SHA256Strategy: HashStrategy {
@@ -13,13 +11,7 @@ public struct SHA256Strategy: HashStrategy {
     public init() {}
 
     public func compute(data: Data) -> Data {
-        #if canImport(CryptoKit)
         let digest = CryptoKit.SHA256.hash(data: data)
         return Data(digest)
-        #else
-        // Uses the existing SHA256 implementation in DesignAlgorithmsKit (from HashAlgorithmProtocol)
-        // Since we are INSIDE DAK, we can access SHA256 enum directly.
-        return SHA256.hash(data: data)
-        #endif
     }
 }

Sources/DesignAlgorithmsKit/Algorithms/Text/FilenameTokenizer.swift

@@ -7,8 +7,8 @@ public struct FilenameTokenizer {
     ///
     /// Examples:
     /// - "PDFExtractor.swift" -> ["PDF", "Extractor", "swift"]
-    /// - "disk_ii_controller" -> ["disk", "ii", "controller"]
-    /// - "iPhone12Pro" -> ["iPhone", "12", "Pro"]
+    /// - "user_profile_view" -> ["user", "profile", "view"]
+    /// - "iPhone12Pro" -> ["i", "Phone", "12", "Pro"] (every lowercase-to-uppercase change splits)
     public static func tokenize(_ filename: String) -> [String] {
         // 1. Replace common separators with spaces
         let separators = CharacterSet(charactersIn: "_-.")

Sources/DesignAlgorithmsKit/Creational/Factory.swift

@@ -22,13 +22,18 @@ public protocol FactoryProduct {
 /// ## Usage
 ///
 /// ```swift
-/// // Register a factory method
-/// ObjectFactory.register(type: "myType") { config in
-///     return MyType(configuration: config)
+/// let factory = ObjectFactory.shared
+///
+/// // Register a factory closure
+/// factory.register(type: "myType") { config in
+///     return try MyType(configuration: config)
 /// }
 ///
-/// // Create object via factory
-/// let object = try ObjectFactory.create(type: "myType", configuration: [:])
+/// // Or register a FactoryProduct type under its type name
+/// factory.register(MyType.self)
+///
+/// // Create an object
+/// let object = try factory.create(type: "myType", configuration: [:])
 /// ```
 public final class ObjectFactory: @unchecked Sendable {
     /// Shared singleton instance (lazy initialization)
@@ -77,7 +82,9 @@ public final class ObjectFactory: @unchecked Sendable {
     }
 
     /// Register a factory method for a FactoryProduct type
-    /// - Parameter type: The FactoryProduct type
+    /// - Parameters:
+    ///   - type: The FactoryProduct type
+    ///   - key: Registration key; defaults to the type's name
     /// Thread-safe: Can be called concurrently
     public func register<T: FactoryProduct>(_ type: T.Type, key: String? = nil) {
         #if !os(WASI) && !arch(wasm32)