Better merge

Author: schmidt-sebastian

packages/firestore/src/core/target.ts

@@ -333,8 +333,6 @@ export function targetGetLowerBound(
           filterValue = MIN_VALUE;
           break;
         case Operator.NOT_IN:
-          // Porting Note: The Web SDK implements notIn queries differently from
-          // Android and only uses a single element array as a notIn bound.
           filterValue = {
             arrayValue: { values: [MIN_VALUE] }
           };
@@ -419,8 +417,6 @@ export function targetGetUpperBound(
           filterValue = MAX_VALUE;
           break;
         case Operator.NOT_IN:
-          // Porting Note: The Web SDK implements notIn queries differently from
-          // Android and only uses a single element array as a notIn bound.
           filterValue = {
             arrayValue: { values: [MAX_VALUE] }
           };

packages/firestore/src/local/index_manager.ts

@@ -103,7 +103,7 @@ export interface IndexManager {
 
   /**
    * Returns the documents that match the given target based on the provided
-   * index. Returns `null` if the target does not have a matching index.
+   * index or `null` if the target does not have a matching index.
    */
   getDocumentsMatchingTarget(
     transaction: PersistenceTransaction,

packages/firestore/src/local/indexeddb_index_manager.ts

@@ -426,13 +426,10 @@ export class IndexedDbIndexManager implements IndexManager {
       const matchingIndexes = indexes.filter(i =>
         targetIndexMatcher.servedByIndex(i)
       );
-      if (matchingIndexes.length === 0) {
-        return null;
-      }
 
       // Return the index that matches the most number of segments.
       matchingIndexes.sort((l, r) => r.fields.length - l.fields.length);
-      return matchingIndexes[0];
+      return matchingIndexes.length > 0 ? matchingIndexes[0] : null;
     });
   }
 
@@ -642,8 +639,9 @@ export class IndexedDbIndexManager implements IndexManager {
   ): PersistencePromise<void> {
     // Porting Note: `getFieldIndexes()` on Web does not cache index lookups as
     // it could be used across different IndexedDB transactions. As any cached
-    // data might invalidated by other multi-tab clients, we can only trust data
-    // within a single IndexedDB transaction. We therefore add a cache here.
+    // data might be invalidated by other multi-tab clients, we can only trust
+    // data within a single IndexedDB transaction. We therefore add a cache
+    // here.
     const memoizedIndexes = new Map<string, FieldIndex[]>();
     return PersistencePromise.forEach(documents, (key, doc) => {
       const memoizedCollectionIndexes = memoizedIndexes.get(