Add ObservableReference

.github/workflows/VerifyChanges.yaml

@@ -1,5 +1,4 @@
 name: Verify Changes
-
 on:
   merge_group:
   pull_request:
@@ -10,7 +9,7 @@ on:
 jobs:
   lint:
     name: Lint
-    runs-on: macos-15
+    runs-on: macos-26
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -20,10 +19,11 @@ jobs:
       - name: Lint
         run: |
           Scripts/lint
+
   build-and-test:
     name: Build and Test (${{ matrix.platform }})
     needs: lint
-    runs-on: macos-15
+    runs-on: macos-26
     strategy:
       fail-fast: false
       matrix:
@@ -44,31 +44,40 @@ jobs:
 #             xcode_destination: "platform=watchOS Simulator,name=GitHub_Actions_Simulator"
 #             simulator_device_type: "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-10-46mm"
 #             simulator_runtime: "com.apple.CoreSimulator.SimRuntime.watchOS-26-0"
+
     env:
       DEV_BUILDS: DevBuilds/Sources
+      OTHER_XCBEAUTIFY_FLAGS: --renderer github-actions
       XCCOV_PRETTY_VERSION: 1.2.0
       XCODE_SCHEME: DevFoundation-Package
       XCODE_DESTINATION: ${{ matrix.xcode_destination }}
       XCODE_TEST_PLAN: AllTests
+      XCODE_TEST_PRODUCTS_PATH: .build/DevFoundation.xctestproducts
+
     steps:
+      - name: Select Xcode 26.0.0
+        run: |
+          sudo xcode-select -s /Applications/Xcode_26.0.0.app
+
       - name: Checkout
         uses: actions/checkout@v4
+
       - name: Checkout DevBuilds
         uses: actions/checkout@v4
         with:
           repository: DevKitOrganization/DevBuilds
           path: DevBuilds
-      - name: Download xccovPretty
+
+      - name: Restore XCTestProducts
         if: github.event_name != 'push'
-        run: |
-          gh release download ${{ env.XCCOV_PRETTY_VERSION }} \
-              --repo DevKitOrganization/xccovPretty \
-              --pattern "xccovPretty-macos.tar.gz" \
-              -O - | tar -xz
-          chmod +x xccovPretty
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        id: cache-xctestproducts-restore
+        uses: actions/cache/restore@v4
+        with:
+          path: ${{ env.XCODE_TEST_PRODUCTS_PATH }}
+          key: cache-xctestproducts-${{ github.workflow }}-${{ matrix.platform }}-${{ github.sha }}
+
       - uses: irgaly/xcode-cache@v1
+        if: steps.cache-xctestproducts-restore.outputs.cache-hit != 'true'
         with:
           key: xcode-cache-deriveddata-${{ github.workflow }}-${{ matrix.platform }}-${{ github.sha }}
           restore-keys: |
@@ -78,61 +87,72 @@ jobs:
           sourcepackages-directory: .build/DerivedData/SourcePackages
           swiftpm-package-resolved-file: Package.resolved
           verbose: true
-      - name: Select Xcode 26.0.0
-        run: |
-          sudo xcode-select -s /Applications/Xcode_26.0.0.app
-      - name: Create Simulator
-        if: ${{ matrix.platform != 'macOS' }}
-        run: |
-          xcrun simctl create GitHub_Actions_Simulator \
-            ${{ matrix.simulator_device_type }} \
-            ${{ matrix.simulator_runtime }}
+
       - name: Build for Testing
-        run: |
-          "$DEV_BUILDS"/build_and_test.sh --action build-for-testing
-      - name: Test
+        id: build-for-testing
+        if: steps.cache-xctestproducts-restore.outputs.cache-hit != 'true'
+        run: ${{ env.DEV_BUILDS }}/build_and_test.sh --action build-for-testing
+
+      - name: Test Without Building
+        id: test-without-building
         if: github.event_name != 'push'
-        run: |
-          "$DEV_BUILDS"/build_and_test.sh --action test
+        run: ${{ env.DEV_BUILDS }}/build_and_test.sh --action test-without-building
+
+      - name: Save XCTestProducts
+        if: failure() && steps.cache-xctestproducts-restore.outputs.cache-hit != 'true'
+        uses: actions/cache/save@v4
+        with:
+          path: ${{ env.XCODE_TEST_PRODUCTS_PATH }}
+          key: ${{ steps.cache-xctestproducts-restore.outputs.cache-primary-key }}
+
       - name: Log Code Coverage
         if: github.event_name != 'push'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          xcrun xccov view --report .build/DevFoundation-Package_test.xcresult --json \
-              | ./xccovPretty --github-comment \
-              > .build/xccovPretty-${{ matrix.platform }}.output
-      - name: Upload Logs
-        uses: actions/upload-artifact@v4
+          gh release download ${{ env.XCCOV_PRETTY_VERSION }} \
+              --repo DevKitOrganization/xccovPretty \
+              --pattern "xccovPretty-macos.tar.gz" \
+              -O - \
+          | tar -xz
+          chmod +x xccovPretty
+
+          xcrun xccov view --report .build/${XCODE_SCHEME}_test-without-building.xcresult --json \
+          | ./xccovPretty --github-comment \
+          > .build/xccovPretty-${{ matrix.platform }}.output
+
+      - name: Upload Logs and XCResults
         if: success() || failure()
-        with:
-          name: Logs-${{ matrix.platform }}
-          path: .build/*.log
-          include-hidden-files: true
-      - name: Upload XCResults
         uses: actions/upload-artifact@v4
-        if: success() || failure()
         with:
-          name: XCResults-${{ matrix.platform }}
-          path: .build/*.xcresult
+          name: Logs_and_XCResults-${{ matrix.platform }}
+          path: |
+            .build/*.log
+            .build/*.xcresult
           include-hidden-files: true
+
       - name: Upload xccovPretty output
         if: github.event_name != 'push'
         uses: actions/upload-artifact@v4
         with:
           name: xccovPrettyOutput-${{ matrix.platform }}
           path: .build/xccovPretty-${{ matrix.platform }}.output
           include-hidden-files: true
+
   post-pr-comments:
     name: Post PR Comments
     needs: build-and-test
+    if: ${{ github.event_name == 'pull_request' }}
     permissions:
       pull-requests: write
     runs-on: ubuntu-latest
-    if: ${{ github.event_name == 'pull_request' }}
+
     steps:
       - name: Download xccovPretty output
         uses: actions/download-artifact@v4
         with:
           name: xccovPrettyOutput-macOS
+
       - name: Post Code Coverage Comment
         uses: thollander/actions-comment-pull-request@v3
         with:

CHANGELOG.md

@@ -3,12 +3,17 @@
 
 ## 1.2.0: September 24, 2025
 
-This release contains updates to `ExecutionGroup` to enable greater flexibility and testability.
-
-There are now two variants of `addTask(priority:operation:)`: the original version for non-throwing
-operations, and a new version for throwing operations. Both functions now have a generic parameter
-for the operation’s return type. Together, these changes allow us to return the created `Task`,
-which you can use to monitor its progress, get its result, or cancel it.
+This release introduces the `ObservableReference` type and updates `ExecutionGroup` to enable
+greater flexibility and testability.
+
+  - This version updates the minimum supported versions of Apple’s OSes to 26.
+  - `ObservableReference` is a simple reference type that conforms to `Observable`. This enables
+    easily observing changes to the value.
+  - There are now two variants of `ExecutionGroup.addTask(priority:operation:)`: the original
+    version for non-throwing operations, and a new version for throwing operations. Both functions
+    now have a generic parameter for the operation’s return type. Together, these changes allow us
+    to return the created `Task`, which you can use to monitor its progress, get its result, or
+    cancel it.
 
 
 ## 1.1.0: September 17, 2025

CLAUDE.md

@@ -217,7 +217,7 @@ Follow the project's Markdown Style Guide:
 
   - Follows Swift API Design Guidelines
   - Uses Swift 6.2 with `ExistentialAny` and `MemberImportVisibility` features enabled
-  - Minimum deployment targets: iOS 18+, macOS 15+, tvOS 18+, visionOS 2+, watchOS 11+
+  - Minimum deployment targets: iOS, macOS, tvOS, visionOS, and watchOS 26
   - Reverse DNS prefix: `com.gauriar.devfoundation`
   - All public APIs are documented and tested
   - Test coverage target: >99%

Package.swift

@@ -10,11 +10,11 @@ let swiftSettings: [SwiftSetting] = [
 let package = Package(
     name: "DevFoundation",
     platforms: [
-        .iOS(.v18),
-        .macOS(.v15),
-        .tvOS(.v18),
-        .visionOS(.v2),
-        .watchOS(.v11),
+        .iOS(.v26),
+        .macOS(.v26),
+        .tvOS(.v26),
+        .visionOS(.v26),
+        .watchOS(.v26),
     ],
     products: [
         .library(
@@ -32,7 +32,7 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.6.1"),
         .package(url: "https://github.com/apple/swift-numerics.git", from: "1.1.0"),
-        .package(url: "https://github.com/DevKitOrganization/DevTesting", from: "1.1.0"),
+        .package(url: "https://github.com/DevKitOrganization/DevTesting", from: "1.2.0"),
         .package(url: "https://github.com/prachigauriar/URLMock.git", from: "1.3.6"),
     ],
     targets: [

README.md

@@ -4,8 +4,8 @@ DevFoundation is a Swift 6 package that provides useful types and protocols for
 and apps on Apple platforms. It makes it easy to consume web services, mock web service responses,
 page through data, post and handle type-safe events across multiple modules, and more.
 
-DevFoundation is fully documented and tested and supports iOS 18+, macOS 15+, tvOS 18+, visionOS 2+,
-and watchOS 11+.
+DevFoundation is fully documented and tested and supports iOS 26+, macOS 26+, tvOS 26+, visionOS 26+,
+and watchOS 26+.
 
 View our [changelog](CHANGELOG.md) to see what’s new.
 

Sources/DevFoundation/Concurrency/ExecutionGroup.swift

@@ -116,26 +116,16 @@ public final class ExecutionGroup: Sendable {
 
     /// Increments the group’s task count and mutates its execution state if needed.
     private func incrementTaskCount() {
-        let isFirstTask = taskCount.withLock { (count) in
-            count += 1
-            return count == 1
-        }
-
-        if isFirstTask {
-            withMutation(keyPath: \.isExecuting) { () }
+        withMutation(keyPath: \.isExecuting) {
+            taskCount.withLock { $0 += 1 }
         }
     }
 
 
     /// Decrements the group’s task count and mutates its execution state if needed.
     private func decrementTaskCount() {
-        let isLastTask = taskCount.withLock { (count) in
-            count -= 1
-            return count == 0
-        }
-
-        if isLastTask {
-            withMutation(keyPath: \.isExecuting) { () }
+        withMutation(keyPath: \.isExecuting) {
+            taskCount.withLock { $0 -= 1 }
         }
     }
 }

Sources/DevFoundation/Documentation.docc/Documentation.md

@@ -28,6 +28,10 @@ for paging through data, and essential utility types for building robust applica
 
 - ``ExpiringValue``
 
+### Observing Changes
+
+- ``ObservableReference``
+
 ### Concurrency Utilities
 
 - ``ExecutionGroup``

Sources/DevFoundation/Utility Types/ObservableReference.swift

@@ -0,0 +1,41 @@
+//
+//  ObservableReference.swift
+//  DevFoundation
+//
+//  Created by Prachi Gauriar on 9/24/25.
+//
+
+import Foundation
+import Synchronization
+
+/// A reference whose value changes can be observed.
+@Observable
+public final class ObservableReference<Value>: Sendable where Value: Sendable {
+    /// A mutex that synchronizes access to the reference’s value.
+    private let valueMutex: Mutex<Value>
+
+
+    /// Creates a new observable reference with the specified initial value.
+    ///
+    /// - Parameter initialValue: The initial value that the reference contains.
+    public init(_ initialValue: Value) {
+        self.valueMutex = .init(initialValue)
+    }
+
+
+    /// The reference’s value.
+    public var value: Value {
+        get {
+            access(keyPath: \.value)
+            return valueMutex.withLock { $0 }
+        }
+
+        set {
+            withMutation(keyPath: \.value) {
+                valueMutex.withLock { (value) in
+                    value = newValue
+                }
+            }
+        }
+    }
+}