Schema upgrade done right.

Author: wu-hui

firebase-firestore/src/main/java/com/google/firebase/firestore/local/SQLiteSchema.java

@@ -49,12 +49,10 @@ class SQLiteSchema {
    * The version of the schema. Increase this by one for each migration added to runMigrations
    * below.
    */
-  static final int VERSION = 12;
-
-  static final int OVERLAY_SUPPORT_VERSION = VERSION + 1;
+  static final int VERSION = 13;
 
   // TODO(indexing): Remove this constant and increment VERSION to enable indexing support
-  static final int INDEXING_SUPPORT_VERSION = OVERLAY_SUPPORT_VERSION + 1;
+  static final int INDEXING_SUPPORT_VERSION = VERSION + 1;
 
   /**
    * The batch size for the sequence number migration in `ensureSequenceNumbers()`.
@@ -80,9 +78,6 @@ void runSchemaUpgrades() {
 
   void runSchemaUpgrades(int fromVersion) {
     int toVersion = VERSION;
-    if (Persistence.OVERLAY_SUPPORT_ENABLED) {
-      toVersion = OVERLAY_SUPPORT_VERSION;
-    }
     if (Persistence.INDEXING_SUPPORT_ENABLED) {
       toVersion = INDEXING_SUPPORT_VERSION;
     }
@@ -170,8 +165,17 @@ void runSchemaUpgrades(int fromVersion, int toVersion) {
     if (fromVersion < 12 && toVersion >= 12) {
       createBundleCache();
     }
+
+    if (fromVersion < 13 && toVersion >= 13) {
+      Preconditions.checkState(
+          Persistence.OVERLAY_SUPPORT_ENABLED || Persistence.INDEXING_SUPPORT_ENABLED);
+      createOverlays();
+      createDataMigrationTable();
+      addPendingDataMigration(Persistence.DATA_MIGRATION_BUILD_OVERLAYS);
+    }
+
     /*
-     * Adding a new migration? READ THIS FIRST!
+     * Adding a new schema upgrade? READ THIS FIRST!
      *
      * Be aware that the SDK version may be downgraded then re-upgraded. This means that running
      * your new migration must not prevent older versions of the SDK from functioning. Additionally,
@@ -182,13 +186,6 @@ void runSchemaUpgrades(int fromVersion, int toVersion) {
      *    maintained invariants from later versions, so migrations that update values cannot assume
      *    that existing values have been properly maintained. Calculate them again, if applicable.
      */
-    if (fromVersion < OVERLAY_SUPPORT_VERSION && toVersion >= OVERLAY_SUPPORT_VERSION) {
-      Preconditions.checkState(
-          Persistence.OVERLAY_SUPPORT_ENABLED || Persistence.INDEXING_SUPPORT_ENABLED);
-      createOverlays();
-      createDataMigrationTable();
-      addPendingDataMigration(Persistence.DATA_MIGRATION_BUILD_OVERLAYS);
-    }
 
     if (fromVersion < INDEXING_SUPPORT_VERSION && toVersion >= INDEXING_SUPPORT_VERSION) {
       Preconditions.checkState(Persistence.INDEXING_SUPPORT_ENABLED);

firebase-firestore/src/test/java/com/google/firebase/firestore/local/SQLiteOverlayMigrationManagerTest.java

@@ -51,9 +51,9 @@ public class SQLiteOverlayMigrationManagerTest {
 
   @Before
   public void setUp() {
+    // Setup persistence to version 12, which is before Overlay.
     persistence =
-        PersistenceTestHelpers.createSQLitePersistenceForVersion(
-            "test-data-migration", SQLiteSchema.OVERLAY_SUPPORT_VERSION - 1);
+        PersistenceTestHelpers.createSQLitePersistenceForVersion("test-data-migration", 12);
     IndexBackfiller indexBackfiller = new IndexBackfiller(persistence, new AsyncQueue());
     localStore =
         new LocalStore(

firebase-firestore/src/test/java/com/google/firebase/firestore/local/SQLiteSchemaTest.java

@@ -638,7 +638,8 @@ public void createsIndexingTables() {
 
   @Test
   public void createsOverlaysAndMigrationTable() {
-    schema.runSchemaUpgrades(0, SQLiteSchema.OVERLAY_SUPPORT_VERSION);
+    // 13 is the version we enable Overlay
+    schema.runSchemaUpgrades(0, 13);
     assertTableExists("document_overlays");
     assertTableExists("data_migrations");