feat: add device info decorator for attributes

Sources/OpenFeature/DeviceInfoAttributeDecorator.swift

@@ -0,0 +1,115 @@
+#if os(iOS)
+import Foundation
+import UIKit
+
+/**
+Helper class to produce device information attributes
+
+The values appended to the attribute come primarily from the Bundle or UIDevice API
+
+AppInfo contains:
+- version: the version name of the app.
+- build: the version code of the app.
+- namespace: the package name of the app.
+
+DeviceInfo contains:
+- manufacturer: the manufacturer of the device.
+- model: the model of the device.
+- type: the type of the device.
+
+OsInfo contains:
+- name: the name of the OS.
+- version: the version of the OS.
+
+Locale contains:
+- locale: the locale of the device.
+- preferred_languages: the preferred languages of the device.
+
+The attributes are only updated when the class is initialized and then static.
+*/
+public class DeviceInfoAttributeDecorator {
+    private let staticAttribute: Value
+
+    /// - Parameters:
+    ///   - withDeviceInfo: If true, includes device hardware information
+    ///   - withAppInfo: If true, includes application metadata
+    ///   - withOsInfo: If true, includes operating system information
+    ///   - withLocale: If true, includes locale and language preferences
+    public init(
+        withDeviceInfo: Bool = false,
+        withAppInfo: Bool = false,
+        withOsInfo: Bool = false,
+        withLocale: Bool = false
+    ) {
+        var attributes: [String: Value] = [:]
+
+        if withDeviceInfo {
+            let device = UIDevice.current
+
+            attributes["device"] = .structure([
+                "manufacturer": .string("Apple"),
+                "model": .string(Self.getDeviceModelIdentifier()),
+                "type": .string(device.model),
+            ])
+        }
+
+        if withAppInfo {
+            let currentVersion: String = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? ""
+            let currentBuild: String = Bundle.main.infoDictionary?["CFBundleVersion"] as? String ?? ""
+            let bundleId = Bundle.main.bundleIdentifier ?? ""
+
+            attributes["app"] = .structure([
+                "version": .string(currentVersion),
+                "build": .string(currentBuild),
+                "namespace": .string(bundleId),
+            ])
+        }
+
+        if withOsInfo {
+            let device = UIDevice.current
+
+            attributes["os"] = .structure([
+                "name": .string(device.systemName),
+                "version": .string(device.systemVersion),
+            ])
+        }
+
+        if withLocale {
+            let locale = Locale.current
+            let preferredLanguages = Locale.preferredLanguages
+
+            // Top level fields
+            attributes["locale"] = .string(locale.identifier) // Locale identifier (e.g., "en_US")
+            attributes["preferred_languages"] = .list(preferredLanguages.map { lang in
+                .string(lang)
+            })
+        }
+
+        self.staticAttribute = .structure(attributes)
+    }
+
+    /// Returns an attribute where values are decorated (appended) according to the configuration of the `DeviceInfoAttributeDecorator`.
+    /// Values provided in the `attributes` parameter take precedence over those appended by this class.
+    public func decorated(attributes attributesToDecorate: [String: Value]) -> [String: Value] {
+        var result = self.staticAttribute.asStructure() ?? [:]
+        attributesToDecorate.forEach { (key: String, value: Value) in
+            result[key] = value
+        }
+        return result
+    }
+
+
+    private static func getDeviceModelIdentifier() -> String {
+        var systemInfo = utsname()
+        uname(&systemInfo)
+        let machineMirror = Mirror(reflecting: systemInfo.machine)
+        let identifier = machineMirror.children
+            .compactMap { element in element.value as? Int8 }
+            .filter { $0 != 0 }
+            .map {
+                Character(UnicodeScalar(UInt8($0)))
+            }
+        return String(identifier)
+    }
+}
+#endif

Tests/OpenFeatureTests/DeviceInfoAttributeDecoratorTests.swift

@@ -0,0 +1,67 @@
+import XCTest
+
+@testable import OpenFeature
+
+final class DeviceInfoAttributeDecoratorTests: XCTestCase {
+    func testEmptyConstructMakesNoOp() {
+        let result = DeviceInfoAttributeDecorator().decorated(attributes: [:])
+        XCTAssertEqual(result.count, 0)
+    }
+
+    func testAddDeviceInfo() {
+        let result = DeviceInfoAttributeDecorator(withDeviceInfo: true).decorated(attributes: [:])
+        XCTAssertEqual(result.count, 1)
+        XCTAssertNotNil(result["device"])
+        XCTAssertNotNil(result["device"]?.asStructure()?["model"])
+        XCTAssertNotNil(result["device"]?.asStructure()?["type"])
+        XCTAssertNotNil(result["device"]?.asStructure()?["manufacturer"])
+    }
+
+    func testAddLocale() {
+        let result = DeviceInfoAttributeDecorator(withLocale: true).decorated(attributes: [:])
+        XCTAssertEqual(result.count, 2)
+        XCTAssertNotNil(result["locale"])
+        XCTAssertNotNil(result["preferred_languages"])
+    }
+
+    func testAddAppInfo() {
+        let result = DeviceInfoAttributeDecorator(withAppInfo: true).decorated(attributes: [:])
+        XCTAssertEqual(result.count, 1)
+        XCTAssertNotNil(result["app"])
+        XCTAssertNotNil(result["app"]?.asStructure()?["version"])
+        XCTAssertNotNil(result["app"]?.asStructure()?["build"])
+        XCTAssertNotNil(result["app"]?.asStructure()?["namespace"])
+    }
+
+    func testAddOsInfo() {
+        let result = DeviceInfoAttributeDecorator(withOsInfo: true).decorated(attributes: [:])
+        XCTAssertEqual(result.count, 1)
+        XCTAssertNotNil(result["os"])
+        XCTAssertNotNil(result["os"]?.asStructure()?["name"])
+        XCTAssertNotNil(result["os"]?.asStructure()?["version"])
+    }
+
+    func testAppendsData() {
+        let result = DeviceInfoAttributeDecorator(
+            withDeviceInfo: true
+        ).decorated(attributes: ["my_key": .double(42.0)])
+        XCTAssertEqual(result.count, 2)
+        XCTAssertEqual(result["my_key"]?.asDouble(), 42.0)
+        XCTAssertNotNil(result["device"])
+    }
+
+    func testCombinedAttributes() {
+        let result = DeviceInfoAttributeDecorator(
+            withDeviceInfo: true,
+            withAppInfo: true,
+            withOsInfo: true,
+            withLocale: true
+        ).decorated(attributes: [:])
+
+        XCTAssertEqual(result.count, 5)
+        XCTAssertNotNil(result["device"])
+        XCTAssertNotNil(result["app"])
+        XCTAssertNotNil(result["os"])
+        XCTAssertNotNil(result["locale"])
+    }
+}