add comments, fix preconditions check

googleapis · May 24, 2021 · 47876e8 · 47876e8
1 parent 61989c7
commit 47876e8
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Showing 2 changed files with 6 additions and 1 deletion.
diff --git a/google-cloud-firestore/src/main/java/com/google/cloud/firestore/RecursiveDelete.java b/google-cloud-firestore/src/main/java/com/google/cloud/firestore/RecursiveDelete.java
@@ -189,8 +189,9 @@ private Query getAllDescendantsQuery() {
       // The parent is the closest ancestor document to the location we're deleting. Since we are
       // deleting a document, the parent is the path of that document.
       parentPath = path;
+      Preconditions.checkState(
+          path.getParent() != null, "Parent of a document should not be null.");
       collectionId = path.getParent().getId();
-      Preconditions.checkState(collectionId != null, "Parent of a document should not be null.");
     } else {
       // The parent is the closest ancestor document to the location we're deleting. Since we are
       // deleting a collection, the parent is the path of the document containing that collection

diff --git a/google-cloud-firestore/src/test/java/com/google/cloud/firestore/RecursiveDeleteTest.java b/google-cloud-firestore/src/test/java/com/google/cloud/firestore/RecursiveDeleteTest.java
@@ -389,6 +389,10 @@ public RunQueryResponse answer(InvocationOnMock invocation) throws Throwable {
               public ApiFuture<BatchWriteResponse> answer(InvocationOnMock mock) throws Exception {
                 if (numDeletesBuffered[0] < cutoff) {
                   numDeletesBuffered[0] += batchWriteResponse.size();
+                  // By waiting for `bufferFuture` to complete, we can guarantee that the writes
+                  // complete after all documents are streamed. Without this future, the test can
+                  // race and complete the writes before the stream is finished, which is a
+                  // different scenario this test is not for.
                   return ApiFutures.transformAsync(
                       bufferFuture,
                       new ApiAsyncFunction<Void, BatchWriteResponse>() {