Support backward migrations for WorkManager.

* Move to Room 1.1.0 as 1.0.0 has a bug when looking for backward migrations.

Test: Added unit tests.
Change-Id: Ia9ad590037df1b4bf14e1449aae0def7fc7a4e07

5 files changed, 121 insertions, 6 deletions

diff --git a/work/integration-tests/testapp/build.gradle b/work/integration-tests/testapp/build.gradle
index 9840d31eef0..7c51a4b1f84 100644
--- a/work/integration-tests/testapp/build.gradle
+++ b/work/integration-tests/testapp/build.gradle
@@ -37,8 +37,8 @@ dependencies {
     implementation project(':work:work-runtime')
     implementation project(':work:work-firebase')
     implementation "android.arch.lifecycle:extensions:1.1.0"
-    implementation "android.arch.persistence.room:runtime:1.0.0"
-    annotationProcessor "android.arch.persistence.room:compiler:1.0.0"
+    implementation "android.arch.persistence.room:runtime:1.1.0"
+    annotationProcessor "android.arch.persistence.room:compiler:1.1.0"
     implementation MULTIDEX
     implementation "com.android.support:recyclerview-v7:26.1.0"
     implementation "com.android.support:appcompat-v7:26.1.0"
diff --git a/work/workmanager/build.gradle b/work/workmanager/build.gradle
index 7c9436fc75b..fedc05213bc 100644
--- a/work/workmanager/build.gradle
+++ b/work/workmanager/build.gradle
@@ -43,10 +43,10 @@ android {
 
 dependencies {
     api "android.arch.lifecycle:extensions:1.1.0"
-    implementation "android.arch.persistence.room:runtime:1.0.0"
-    annotationProcessor "android.arch.persistence.room:compiler:1.0.0"
+    implementation "android.arch.persistence.room:runtime:1.1.0"
+    annotationProcessor "android.arch.persistence.room:compiler:1.1.0"
     androidTestImplementation "android.arch.core:core-testing:1.1.0"
-    androidTestImplementation "android.arch.persistence.room:testing:1.0.0"
+    androidTestImplementation "android.arch.persistence.room:testing:1.1.0"
     androidTestImplementation(TEST_RUNNER)
     androidTestImplementation(ESPRESSO_CORE)
     androidTestImplementation(MOCKITO_CORE, libs.exclude_bytebuddy) // DexMaker has its own MockMaker
diff --git a/work/workmanager/src/androidTest/java/androidx/work/WorkDatabaseMigrationTest.java b/work/workmanager/src/androidTest/java/androidx/work/WorkDatabaseMigrationTest.java
index 77ebc7ddd8c..1c1893f2cf4 100644
--- a/work/workmanager/src/androidTest/java/androidx/work/WorkDatabaseMigrationTest.java
+++ b/work/workmanager/src/androidTest/java/androidx/work/WorkDatabaseMigrationTest.java
@@ -45,15 +45,20 @@ public class WorkDatabaseMigrationTest {
 
     private static final String TEST_DATABASE = "workdatabase-test";
     private static final boolean VALIDATE_DROPPED_TABLES = true;
+    private static final int OLD_VERSION = 1;
     private static final int NEW_VERSION = 2;
     private static final String COLUMN_WORKSPEC_ID = "work_spec_id";
     private static final String COLUMN_SYSTEM_ID = "system_id";
+    private static final String COLUMN_ALARM_ID = "alarm_id";
 
     // Queries
     private static final String INSERT_ALARM_INFO = "INSERT INTO alarmInfo VALUES (?, ?)";
+    private static final String INSERT_SYSTEM_ID_INFO = "INSERT INTO systemIdInfo VALUES (?, ?)";
     private static final String CHECK_SYSTEM_ID_INFO = "SELECT * FROM systemIdInfo";
+    private static final String CHECK_ALARM_INFO = "SELECT * FROM alarmInfo";
     private static final String CHECK_TABLE_NAME = "SELECT * FROM %s";
     private static final String TABLE_ALARM_INFO = "alarmInfo";
+    private static final String TABLE_SYSTEM_ID_INFO = "systemIdInfo";
     private static final String TABLE_WORKSPEC = "WorkSpec";
     private static final String TABLE_WORKTAG = "WorkTag";
     private static final String TABLE_WORKNAME = "WorkName";
@@ -79,7 +84,7 @@ public class WorkDatabaseMigrationTest {
     @MediumTest
     public void testMigrationVersion1To2() throws IOException {
         SupportSQLiteDatabase database =
-                mMigrationTestHelper.createDatabase(TEST_DATABASE, 1);
+                mMigrationTestHelper.createDatabase(TEST_DATABASE, OLD_VERSION);
 
         String workSpecId1 = UUID.randomUUID().toString();
         String workSpecId2 = UUID.randomUUID().toString();
@@ -113,6 +118,91 @@ public class WorkDatabaseMigrationTest {
         database.close();
     }
 
+    @Test
+    @MediumTest
+    public void testMigrationVersion2To1() throws IOException {
+        SupportSQLiteDatabase database =
+                mMigrationTestHelper.createDatabase(TEST_DATABASE, NEW_VERSION);
+
+        String workSpecId1 = UUID.randomUUID().toString();
+        String workSpecId2 = UUID.randomUUID().toString();
+
+        // insert systemIdInfo
+        database.execSQL(INSERT_SYSTEM_ID_INFO, new Object[]{workSpecId1, 1});
+        database.execSQL(INSERT_SYSTEM_ID_INFO, new Object[]{workSpecId2, 2});
+
+        database.close();
+
+
+        database = mMigrationTestHelper.runMigrationsAndValidate(
+                TEST_DATABASE,
+                OLD_VERSION,
+                VALIDATE_DROPPED_TABLES,
+                WorkDatabaseMigrations.MIGRATION_2_1);
+
+        Cursor cursor = database.query(CHECK_ALARM_INFO);
+        assertThat(cursor.getCount(), is(2));
+        cursor.moveToFirst();
+        assertThat(cursor.getString(cursor.getColumnIndex(COLUMN_WORKSPEC_ID)), is(workSpecId1));
+        assertThat(cursor.getInt(cursor.getColumnIndex(COLUMN_ALARM_ID)), is(1));
+        cursor.moveToNext();
+        assertThat(cursor.getString(cursor.getColumnIndex(COLUMN_WORKSPEC_ID)), is(workSpecId2));
+        assertThat(cursor.getInt(cursor.getColumnIndex(COLUMN_ALARM_ID)), is(2));
+        cursor.close();
+
+        assertThat(checkExists(database, TABLE_SYSTEM_ID_INFO), is(false));
+        assertThat(checkExists(database, TABLE_WORKSPEC), is(true));
+        assertThat(checkExists(database, TABLE_WORKTAG), is(true));
+        assertThat(checkExists(database, TABLE_WORKNAME), is(true));
+        database.close();
+    }
+
+    @Test
+    @MediumTest
+    public void testMigrationVersion1To2To1() throws IOException {
+        SupportSQLiteDatabase database =
+                mMigrationTestHelper.createDatabase(TEST_DATABASE, OLD_VERSION);
+
+        String workSpecId1 = UUID.randomUUID().toString();
+        String workSpecId2 = UUID.randomUUID().toString();
+
+        // insert alarmInfos
+        database.execSQL(INSERT_ALARM_INFO, new Object[]{workSpecId1, 1});
+        database.execSQL(INSERT_ALARM_INFO, new Object[]{workSpecId2, 2});
+
+        database.close();
+
+        database = mMigrationTestHelper.runMigrationsAndValidate(
+                TEST_DATABASE,
+                NEW_VERSION,
+                VALIDATE_DROPPED_TABLES,
+                WorkDatabaseMigrations.MIGRATION_1_2);
+
+        database.close();
+
+        database = mMigrationTestHelper.runMigrationsAndValidate(
+                TEST_DATABASE,
+                OLD_VERSION,
+                VALIDATE_DROPPED_TABLES,
+                WorkDatabaseMigrations.MIGRATION_2_1);
+
+        Cursor cursor = database.query(CHECK_ALARM_INFO);
+        assertThat(cursor.getCount(), is(2));
+        cursor.moveToFirst();
+        assertThat(cursor.getString(cursor.getColumnIndex(COLUMN_WORKSPEC_ID)), is(workSpecId1));
+        assertThat(cursor.getInt(cursor.getColumnIndex(COLUMN_ALARM_ID)), is(1));
+        cursor.moveToNext();
+        assertThat(cursor.getString(cursor.getColumnIndex(COLUMN_WORKSPEC_ID)), is(workSpecId2));
+        assertThat(cursor.getInt(cursor.getColumnIndex(COLUMN_ALARM_ID)), is(2));
+        cursor.close();
+
+        assertThat(checkExists(database, TABLE_SYSTEM_ID_INFO), is(false));
+        assertThat(checkExists(database, TABLE_WORKSPEC), is(true));
+        assertThat(checkExists(database, TABLE_WORKTAG), is(true));
+        assertThat(checkExists(database, TABLE_WORKNAME), is(true));
+        database.close();
+    }
+
     private boolean checkExists(SupportSQLiteDatabase database, String tableName) {
         Cursor cursor = null;
         try {
diff --git a/work/workmanager/src/main/java/androidx/work/impl/WorkDatabase.java b/work/workmanager/src/main/java/androidx/work/impl/WorkDatabase.java
index e4ed3842027..e5d5f9d0f98 100644
--- a/work/workmanager/src/main/java/androidx/work/impl/WorkDatabase.java
+++ b/work/workmanager/src/main/java/androidx/work/impl/WorkDatabase.java
@@ -97,6 +97,7 @@ public abstract class WorkDatabase extends RoomDatabase {
         }
         return builder.addCallback(generateCleanupCallback())
                 .addMigrations(WorkDatabaseMigrations.MIGRATION_1_2)
+                .addMigrations(WorkDatabaseMigrations.MIGRATION_2_1)
                 .build();
     }
 
diff --git a/work/workmanager/src/main/java/androidx/work/impl/WorkDatabaseMigrations.java b/work/workmanager/src/main/java/androidx/work/impl/WorkDatabaseMigrations.java
index 609410267bc..0c3e3db484c 100644
--- a/work/workmanager/src/main/java/androidx/work/impl/WorkDatabaseMigrations.java
+++ b/work/workmanager/src/main/java/androidx/work/impl/WorkDatabaseMigrations.java
@@ -42,11 +42,22 @@ public class WorkDatabaseMigrations {
                     + " INTEGER NOT NULL, PRIMARY KEY(`work_spec_id`), FOREIGN KEY(`work_spec_id`)"
                     + " REFERENCES `WorkSpec`(`id`) ON UPDATE CASCADE ON DELETE CASCADE )";
 
+    private static final String CREATE_ALARM_INFO =
+            "CREATE TABLE IF NOT EXISTS `alarmInfo` (`work_spec_id` TEXT NOT NULL, `alarm_id`"
+                    + " INTEGER NOT NULL, PRIMARY KEY(`work_spec_id`), FOREIGN KEY"
+                    + "(`work_spec_id`) REFERENCES `WorkSpec`(`id`) ON UPDATE CASCADE ON DELETE "
+                    + "CASCADE )";
+
     private static final String MIGRATE_ALARM_INFO_TO_SYSTEM_ID_INFO =
             "INSERT INTO systemIdInfo(work_spec_id, system_id) "
                     + "SELECT work_spec_id, alarm_id AS system_id FROM alarmInfo";
 
+    private static final String MIGRATE_SYSTEM_ID_INFO_TO_ALARM_INFO =
+            "INSERT INTO alarmInfo(work_spec_id, alarm_id) "
+                    + "SELECT work_spec_id, system_id AS alarm_id FROM systemIdInfo";
+
     private static final String REMOVE_ALARM_INFO = "DROP TABLE IF EXISTS alarmInfo";
+    private static final String REMOVE_SYSTEM_ID_INFO = "DROP TABLE IF EXISTS systemIdInfo";
 
 
     /**
@@ -61,4 +72,17 @@ public class WorkDatabaseMigrations {
             database.execSQL(REMOVE_ALARM_INFO);
         }
     };
+
+    /**
+     * Removes the {@code alarmInfo} table and substitutes it for a more general
+     * {@code systemIdInfo} table.
+     */
+    public static Migration MIGRATION_2_1 = new Migration(VERSION_2, VERSION_1) {
+        @Override
+        public void migrate(@NonNull SupportSQLiteDatabase database) {
+            database.execSQL(CREATE_ALARM_INFO);
+            database.execSQL(MIGRATE_SYSTEM_ID_INFO_TO_ALARM_INFO);
+            database.execSQL(REMOVE_SYSTEM_ID_INFO);
+        }
+    };
 }