ci: add macOS unit test coverage

.github/workflows/xcode-build.yml

@@ -25,3 +25,12 @@ jobs:
             -scheme potassiumProvider \
             -destination 'platform=macOS' \
             CODE_SIGNING_ALLOWED=NO
+
+      - name: Run unit tests on macOS
+        run: |
+          xcodebuild test \
+            -project potassiumProvider.xcodeproj \
+            -scheme potassiumProvider \
+            -destination 'platform=macOS' \
+            MACOSX_DEPLOYMENT_TARGET=26.4 \
+            CODE_SIGNING_ALLOWED=NO

README.md

@@ -101,7 +101,7 @@ xcodebuild build \
   -destination 'generic/platform=visionOS'
 ```
 
-Run tests:
+Run unit tests:
 
 ```sh
 xcodebuild test \
@@ -110,7 +110,7 @@ xcodebuild test \
   -destination 'platform=iOS Simulator,OS=26.5,name=iPhone 17'
 ```
 
-Run tests on Mac as well:
+Run unit tests on Mac as well:
 
 ```sh
 xcodebuild test \
@@ -119,7 +119,7 @@ xcodebuild test \
   -destination 'platform=macOS'
 ```
 
-Run tests on visionOS as well:
+Run unit tests on visionOS as well:
 
 ```sh
 xcodebuild test \
@@ -128,16 +128,9 @@ xcodebuild test \
   -destination 'platform=visionOS Simulator,OS=26.5,name=Apple Vision Pro'
 ```
 
-If the full scheme stalls during simulator/UI-test cleanup, this has previously
-worked more reliably:
-
-```sh
-xcodebuild test \
-  -project potassiumProvider.xcodeproj \
-  -scheme potassiumProvider \
-  -destination 'platform=iOS Simulator,OS=26.5,name=iPhone 17' \
-  -parallel-testing-enabled NO
-```
+The shared scheme's Test action contains `potassiumProviderTests` only. UI
+automation remains a separate Xcode test-target workflow and does not run in
+the command-line matrix above.
 
 Use `xcodebuild -showdestinations` to copy exact Mac or visionOS destinations if
 local Xcode requires a more specific variant.

doc/TESTING_AND_DEVELOPMENT.md

@@ -14,6 +14,10 @@ source of truth.
 - Unit test target: `potassiumProviderTests`
 - UI test target: `potassiumProviderUITests`
 
+The shared `potassiumProvider` scheme runs `potassiumProviderTests` in its Test
+action. UI automation remains a separate Xcode test-target workflow and is not
+part of the shared scheme's command-line test path.
+
 Do not use Tuist or root-level SwiftPM commands for validation unless the
 project is intentionally migrated.
 
@@ -70,7 +74,7 @@ xcodebuild build \
   -destination 'platform=macOS'
 ```
 
-Run all tests:
+Run unit tests:
 
 ```sh
 xcodebuild test \
@@ -79,7 +83,7 @@ xcodebuild test \
   -destination 'platform=iOS Simulator,OS=26.5,name=iPhone 17'
 ```
 
-Run all tests on Mac as well:
+Run unit tests on Mac as well:
 
 ```sh
 xcodebuild test \
@@ -88,45 +92,36 @@ xcodebuild test \
   -destination 'platform=macOS'
 ```
 
-Run only unit tests:
-
-```sh
-xcodebuild test \
-  -project potassiumProvider.xcodeproj \
-  -scheme potassiumProvider \
-  -destination 'platform=iOS Simulator,OS=26.5,name=iPhone 17' \
-  -only-testing:potassiumProviderTests
-```
-
-If the full scheme stalls during simulator/UI-test cleanup, retry with:
-
-```sh
-xcodebuild test \
-  -project potassiumProvider.xcodeproj \
-  -scheme potassiumProvider \
-  -destination 'platform=iOS Simulator,OS=26.5,name=iPhone 17' \
-  -parallel-testing-enabled NO
-```
-
 Use `xcodebuild -showdestinations` to copy the exact Mac destination if local
 Xcode requires a more specific macOS variant.
 
 ## Continuous Integration
 
-GitHub Actions runs an unsigned macOS build for every pull request and every
-push to `main`. The build uses the `macos-26` runner and its default Xcode 26.5
-installation:
+GitHub Actions runs an unsigned macOS build followed by the macOS unit tests for
+every pull request and every push to `main`. The job uses the `macos-26` runner
+and its default Xcode 26.5 installation:
 
 ```sh
 xcodebuild build \
   -project potassiumProvider.xcodeproj \
   -scheme potassiumProvider \
   -destination 'platform=macOS' \
   CODE_SIGNING_ALLOWED=NO
+
+xcodebuild test \
+  -project potassiumProvider.xcodeproj \
+  -scheme potassiumProvider \
+  -destination 'platform=macOS' \
+  MACOSX_DEPLOYMENT_TARGET=26.4 \
+  CODE_SIGNING_ALLOWED=NO
 ```
 
-This initial workflow checks compilation only. Unit tests, UI tests, caching,
-and iOS Simulator and visionOS jobs remain outside its scope.
+The build and test commands run as consecutive steps in the same job and share
+the resolved package checkout and DerivedData directory. The CI-only
+deployment-target override allows the tests to run on the hosted runner's
+macOS 26.4 installation without changing the project's macOS 26.5 deployment
+target. UI tests, caching, iOS Simulator and visionOS jobs, and the manual File
+Provider release gates remain outside its scope.
 
 ## Test Style
 

potassiumProvider.xcodeproj/xcshareddata/xcschemes/potassiumProvider.xcscheme

@@ -35,20 +35,6 @@
                ReferencedContainer = "container:potassiumProvider.xcodeproj">
             </BuildableReference>
          </BuildActionEntry>
-         <BuildActionEntry
-            buildForTesting = "YES"
-            buildForRunning = "NO"
-            buildForProfiling = "NO"
-            buildForArchiving = "NO"
-            buildForAnalyzing = "NO">
-            <BuildableReference
-               BuildableIdentifier = "primary"
-               BlueprintIdentifier = "C098429C2FF847B000CB8B7E"
-               BuildableName = "potassiumProviderUITests.xctest"
-               BlueprintName = "potassiumProviderUITests"
-               ReferencedContainer = "container:potassiumProvider.xcodeproj">
-            </BuildableReference>
-         </BuildActionEntry>
       </BuildActionEntries>
    </BuildAction>
    <TestAction
@@ -78,16 +64,6 @@
                ReferencedContainer = "container:potassiumProvider.xcodeproj">
             </BuildableReference>
          </TestableReference>
-         <TestableReference
-            skipped = "NO">
-            <BuildableReference
-               BuildableIdentifier = "primary"
-               BlueprintIdentifier = "C098429C2FF847B000CB8B7E"
-               BuildableName = "potassiumProviderUITests.xctest"
-               BlueprintName = "potassiumProviderUITests"
-               ReferencedContainer = "container:potassiumProvider.xcodeproj">
-            </BuildableReference>
-         </TestableReference>
       </Testables>
    </TestAction>
    <LaunchAction