✨ Add Identified nibble.

Author: connor-ricks

.swiftpm/xcode/xcshareddata/xcschemes/Identified.xcscheme

@@ -0,0 +1,66 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1500"
+   version = "1.7">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "Identified"
+               BuildableName = "Identified"
+               BlueprintName = "Identified"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "Identified"
+            BuildableName = "Identified"
+            BlueprintName = "Identified"
+            ReferencedContainer = "container:">
+         </BuildableReference>
+      </MacroExpansion>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

Package.swift

@@ -13,12 +13,16 @@ let package = Package(
     products: [
         .library(name: "Cache", targets: ["Cache"]),
         .library(name: "Extensions", targets: ["Extensions"]),
+        .library(name: "Identified", targets: ["Identified"]),
     ],
     targets: [
         .target(name: "Cache"),
         .testTarget(name: "CacheTests", dependencies: ["Cache"]),
 
         .target(name: "Extensions"),
         .testTarget(name: "ExtensionsTests", dependencies: ["Extensions"]),
+        
+        .target(name: "Identified"),
+        .testTarget(name: "IdentifiedTests", dependencies: ["Identified"]),
     ]
 )

Sources/Identified/Identified.swift

@@ -0,0 +1,43 @@
+import Foundation
+
+// MARK: - Identified
+
+/// An object that is uniquely identifiable.
+public protocol Identified {
+    associatedtype IdentifierValue: Hashable
+    var id: Identifier<Self, IdentifierValue> { get }
+}
+
+// MARK: - Identifier
+
+/// An identified that identifies a particular object type.
+public struct Identifier<Object, IdentifierValue: Hashable>: Hashable, Equatable {
+    
+    /// The underlying value of the identified.
+    public let value: IdentifierValue
+    
+    /// Creates an identified backed by the provided value.
+    ///
+    /// - Parameter value: The value that backs this identified.
+    public init(value: IdentifierValue) {
+        self.value = value
+    }
+}
+
+// MARK: - Identifier + Decodable
+
+extension Identifier: Decodable where IdentifierValue: Decodable {
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        value = try container.decode(IdentifierValue.self)
+    }
+}
+
+// MARK: - Identifier + Encodable
+
+extension Identifier: Encodable where IdentifierValue: Encodable {
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(value)
+    }
+}

Tests/IdentifiedTests/IdentifiedTests.swift

@@ -0,0 +1,33 @@
+@testable import Identified
+import XCTest
+
+class IdentifiedTests: XCTestCase {
+    
+    // MARK: Dog
+    
+    struct Dog: Identified, Codable {
+        var id: Identifier<Self, Int>
+    }
+    
+    // MARK: Tests
+    
+    func test_identifierValue_whenCreated_matchesExpectation() {
+        let dog = Dog(id: .init(value: 1))
+        XCTAssertEqual(dog.id.value, 1)
+    }
+    
+    func test_identifierValue_whenDecoded_matchesExpectation() throws {
+        let data = #"{ "id": 1 }"#.data(using: .utf8)!
+        let decoder = JSONDecoder()
+        let dog = try decoder.decode(Dog.self, from: data)
+        XCTAssertEqual(dog.id.value, 1)
+    }
+    
+    func test_identifierValue_whenEncoded_matchesExpectation() throws {
+        let dog = Dog(id: .init(value: 1))
+        let encoder = JSONEncoder()
+        let data = try encoder.encode(dog)
+        XCTAssertEqual(data, #"{"id":1}"#.data(using: .utf8)!)
+    }
+}
+