Run unit tests in CI and characterize the git auth controller

.github/workflows/ci_verify_build.yml

@@ -44,6 +44,40 @@ jobs:
           if-no-files-found: ignore
           retention-days: 7
 
+  unit-tests:
+    name: Unit tests
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 17
+          cache: gradle
+
+      - name: Set up Android SDK
+        uses: android-actions/setup-android@v3
+
+      - name: Make gradlew executable
+        run: chmod +x ./gradlew
+
+      - name: Run unit tests
+        run: ./gradlew test --no-daemon --stacktrace
+
+      - name: Upload test reports
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: test-reports-${{ github.run_number }}
+          path: '**/build/reports/tests/**'
+          if-no-files-found: ignore
+          retention-days: 7
+
   build:
     name: Assemble debug
     runs-on: ubuntu-latest

data/local/src/test/java/com/ahmadkharfan/androidstudiolite/data/local/DataStorePreferencesRepositoryTest.kt

@@ -9,6 +9,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.job
 import kotlinx.coroutines.runBlocking
 import org.junit.Assert.assertEquals
 import org.junit.Before
@@ -36,7 +37,12 @@ class DataStorePreferencesRepositoryTest {
                 PreferenceDataStoreFactory.create(scope = scope) { file }
             return runBlocking { block(DataStorePreferencesRepository(store)) }
         } finally {
+            // Cancelling is not enough: DataStore only releases its exclusive connection to the file
+            // once the scope's job has actually completed. Without joining, the next withRepository
+            // can open a second DataStore on the same file and fail with "There are multiple
+            // DataStores active for the same file" — a race that only shows up on slower machines.
             scope.cancel()
+            runBlocking { scope.coroutineContext.job.join() }
         }
     }