Revert "Allowing empty merges" (#2965)

schmidt-sebastian · web-flow · commit 112b25c6d0c0 · 2018-02-27T07:50:25.000-08:00
diff --git a/google-cloud-firestore/src/main/java/com/google/cloud/firestore/UpdateBuilder.java b/google-cloud-firestore/src/main/java/com/google/cloud/firestore/UpdateBuilder.java
@@ -245,6 +245,7 @@ private T performSet(
         DocumentTransform.fromFieldPathMap(documentReference, documentData);
 
     if (options.isMerge()) {
+      Preconditions.checkArgument(!fields.isEmpty(), "Data to merge cannot be empty.");
       if (options.getFieldMask() != null) {
         List<FieldPath> fieldMask = new ArrayList<>(options.getFieldMask());
         fieldMask.removeAll(documentTransform.getFields());
@@ -256,12 +257,11 @@ private T performSet(
 
     Mutation mutation = addMutation();
 
-    boolean hasDocumentData = !documentSnapshot.isEmpty() || !documentMask.isEmpty();
-
-    if (!options.isMerge()) {
-      mutation.document = documentSnapshot.toPb();
-    } else if (hasDocumentData || documentTransform.isEmpty()) {
+    if (!options.isMerge() || !documentSnapshot.isEmpty() || !documentMask.isEmpty()) {
       mutation.document = documentSnapshot.toPb();
+    }
+
+    if (!documentMask.isEmpty()) {
       mutation.document.setUpdateMask(documentMask.toPb());
     }
 
diff --git a/google-cloud-firestore/src/test/java/com/google/cloud/firestore/ConformanceTest.java b/google-cloud-firestore/src/test/java/com/google/cloud/firestore/ConformanceTest.java
@@ -85,8 +85,7 @@ public class ConformanceTest {
   private interface ConformanceTestCase extends Test, Describable {}
 
   /** Excluded tests by test description. */
-  private final Set<String> excludedTests =
-      Collections.singleton("set: MergeAll cannot be specified with empty data."); // b/73495873
+  private final Set<String> excludedTests = Collections.emptySet();
 
   /** If non-empty, only runs tests included in this set. */
   private final Set<String> includedTests = Collections.emptySet();
diff --git a/google-cloud-firestore/src/test/java/com/google/cloud/firestore/DocumentReferenceTest.java b/google-cloud-firestore/src/test/java/com/google/cloud/firestore/DocumentReferenceTest.java
@@ -411,20 +411,6 @@ public void setDocumentWithMerge() throws Exception {
     }
   }
 
-  @Test
-  public void setDocumentWithEmptyMerge() throws Exception {
-    doReturn(SINGLE_WRITE_COMMIT_RESPONSE)
-        .when(firestoreMock)
-        .sendRequest(
-            commitCapture.capture(), Matchers.<UnaryCallable<CommitRequest, CommitResponse>>any());
-
-    documentReference.set(map(), SetOptions.merge()).get();
-
-    assertCommitEquals(
-        commit(set(Collections.<String, Value>emptyMap(), Collections.<String>emptyList())),
-        commitCapture.getValue());
-  }
-
   @Test
   public void setDocumentWithNestedMerge() throws Exception {
     doReturn(SINGLE_WRITE_COMMIT_RESPONSE)
