Notifications: simplify the flow by removing persistence (#2924)

* Notifications: simplify the flow by removing persistence. 
* Bump of minSdk to `24` (Android 7).
* Add migration to remove `notification.bin` file

features/migration/impl/build.gradle.kts

@@ -40,6 +40,7 @@ dependencies {
     testImplementation(libs.test.junit)
     testImplementation(libs.coroutines.test)
     testImplementation(libs.molecule.runtime)
+    testImplementation(libs.test.robolectric)
     testImplementation(libs.test.truth)
     testImplementation(libs.test.turbine)
     testImplementation(projects.libraries.sessionStorage.implMemory)

features/migration/impl/src/main/kotlin/io/element/android/features/migration/impl/migrations/AppMigration04.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2024 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.migration.impl.migrations
+
+import android.content.Context
+import com.squareup.anvil.annotations.ContributesMultibinding
+import io.element.android.libraries.di.AppScope
+import io.element.android.libraries.di.ApplicationContext
+import javax.inject.Inject
+
+/**
+ * Remove notifications.bin file, used to store notification data locally.
+ */
+@ContributesMultibinding(AppScope::class)
+class AppMigration04 @Inject constructor(
+    @ApplicationContext private val context: Context,
+) : AppMigration {
+    companion object {
+        internal const val NOTIFICATION_FILE_NAME = "notifications.bin"
+    }
+    override val order: Int = 4
+
+    override suspend fun migrate() {
+        runCatching { context.getDatabasePath(NOTIFICATION_FILE_NAME).delete() }
+    }
+}

features/migration/impl/src/test/kotlin/io/element/android/features/migration/impl/migrations/AppMigration04Test.kt

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2024 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.migration.impl.migrations
+
+import androidx.test.platform.app.InstrumentationRegistry
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class AppMigration04Test {
+    @Test
+    fun `test migration`() = runTest {
+        val context = InstrumentationRegistry.getInstrumentation().context
+
+        // Create fake temporary file at the path to be deleted
+        val file = context.getDatabasePath(AppMigration04.NOTIFICATION_FILE_NAME)
+        file.parentFile?.mkdirs()
+        file.createNewFile()
+        assertThat(file.exists()).isTrue()
+
+        val migration = AppMigration04(context)
+
+        migration.migrate()
+
+        // Check that the file has been deleted
+        assertThat(file.exists()).isFalse()
+    }
+}