Small indexing fixes (#3275)

Author: schmidt-sebastian

firebase-firestore/src/main/java/com/google/firebase/firestore/FirebaseFirestore.java

@@ -289,7 +289,7 @@ public FirebaseApp getApp() {
   }
 
   /**
-   * Configures Indexing for local query execution. Any previous index configuration is overridden.
+   * Configures indexing for local query execution. Any previous index configuration is overridden.
    * The Task resolves once the index configuration has been persisted.
    *
    * <p>The index entries themselves are created asynchronously. You can continue to use queries
@@ -307,10 +307,14 @@ public FirebaseApp getApp() {
   Task<Void> setIndexConfiguration(String json) {
     ensureClientConfigured();
 
+    if (!settings.isPersistenceEnabled()) {
+      throw new IllegalStateException("Cannot enable indexes when persistence is disabled");
+    }
+
     // Preconditions.checkState(BuildConfig.ENABLE_INDEXING, "Indexing support is not yet
     // available.");
 
-    List<FieldIndex> parsedIndices = new ArrayList<>();
+    List<FieldIndex> parsedIndexes = new ArrayList<>();
 
     // See https://firebase.google.com/docs/reference/firestore/indexes/#json_format for the
     // format of the index definition. Unlike the backend, the SDK does not distinguish between
@@ -320,9 +324,9 @@ Task<Void> setIndexConfiguration(String json) {
       JSONObject jsonObject = new JSONObject(json);
 
       if (jsonObject.has("indexes")) {
-        JSONArray indices = jsonObject.getJSONArray("indexes");
-        for (int i = 0; i < indices.length(); ++i) {
-          JSONObject definition = indices.getJSONObject(i);
+        JSONArray indexes = jsonObject.getJSONArray("indexes");
+        for (int i = 0; i < indexes.length(); ++i) {
+          JSONObject definition = indexes.getJSONObject(i);
           String collectionGroup = definition.getString("collectionGroup");
           List<FieldIndex.Segment> segments = new ArrayList<>();
 
@@ -340,7 +344,7 @@ Task<Void> setIndexConfiguration(String json) {
             }
           }
 
-          parsedIndices.add(
+          parsedIndexes.add(
               FieldIndex.create(
                   FieldIndex.UNKNOWN_ID, collectionGroup, segments, FieldIndex.INITIAL_STATE));
         }
@@ -349,7 +353,7 @@ Task<Void> setIndexConfiguration(String json) {
       throw new IllegalArgumentException("Failed to parse index configuration", e);
     }
 
-    return client.configureFieldIndexes(parsedIndices);
+    return client.configureFieldIndexes(parsedIndexes);
   }
 
   /**

firebase-firestore/src/main/java/com/google/firebase/firestore/model/FieldIndex.java

@@ -26,7 +26,7 @@
  * An index definition for field indices in Firestore.
  *
  * <p>Every index is associated with a collection. The definition contains a list of fields and
- * their indexkind (which can be {@link Segment.Kind#ASCENDING}, {@link Segment.Kind#DESCENDING} or
+ * their index kind (which can be {@link Segment.Kind#ASCENDING}, {@link Segment.Kind#DESCENDING} or
  * {@link Segment.Kind#CONTAINS}) for ArrayContains/ArrayContainsAny queries.
  *
  * <p>Unlike the backend, the SDK does not differentiate between collection or collection