small fixes

Author: var-const

packages/firestore/src/local/local_documents_view.ts

@@ -155,11 +155,9 @@ export class LocalDocumentsView {
       })
       .next(matchingMutationBatches => {
         for (const batch of matchingMutationBatches) {
-          // TODO(mikelehen): PERF: Check if this mutation actually affects the
-          // query to reduce work.
           for (const mutation of batch.mutations) {
             const key = mutation.key;
-
+            // Only process documents belonging to the collection.
             if (!query.path.isImmediateParentOf(key.path)) {
               continue;
             }

packages/firestore/src/local/mutation_queue.ts

@@ -154,10 +154,10 @@ export interface MutationQueue extends GarbageSource {
   ): PersistencePromise<MutationBatch[]>;
 
   /**
-   * Finds all mutation batches that could possibly affect the given
-   * set of document keys. Not all mutations in a batch will necessarily affect
-   * each key, so when looping through the batch you'll need to
-   * check that the mutation itself matches the key.
+   * Finds all mutation batches that could possibly affect the given set of
+   * document keys. Not all mutations in a batch will necessarily affect each
+   * key, so when looping through the batch you'll need to check that the
+   * mutation itself matches the key.
    *
    * Batches are guaranteed to be in sorted order.
    *

packages/firestore/test/unit/local/mutation_queue.test.ts

@@ -384,7 +384,6 @@ function genericMutationQueueTests(): void {
     const matches = await mutationQueue.getAllMutationBatchesAffectingDocumentKey(
       key('foo/bar')
     );
-    expect(matches.length).to.deep.equal(expected.length);
     expectEqualArrays(matches, expected);
   });
 
@@ -409,7 +408,6 @@ function genericMutationQueueTests(): void {
         .add(key('foo/bar'))
         .add(key('foo/baz'))
     );
-    expect(matches.length).to.deep.equal(expected.length);
     expectEqualArrays(matches, expected);
   });