Add TestUtil.fieldMask(String...) to simplify creating FieldMasks.

Author: rsgowman

firebase-firestore/src/test/java/com/google/firebase/firestore/local/LocalSerializerTest.java

@@ -18,6 +18,7 @@
 import static com.google.firebase.firestore.testutil.TestUtil.deletedDoc;
 import static com.google.firebase.firestore.testutil.TestUtil.doc;
 import static com.google.firebase.firestore.testutil.TestUtil.field;
+import static com.google.firebase.firestore.testutil.TestUtil.fieldMask;
 import static com.google.firebase.firestore.testutil.TestUtil.key;
 import static com.google.firebase.firestore.testutil.TestUtil.map;
 import static com.google.firebase.firestore.testutil.TestUtil.setMutation;
@@ -44,7 +45,6 @@
 import com.google.firestore.v1beta1.Value;
 import com.google.firestore.v1beta1.Write;
 import com.google.protobuf.ByteString;
-import java.util.HashSet;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -72,7 +72,7 @@ public void testEncodesMutationBatch() {
         new PatchMutation(
             key("bar/baz"),
             TestUtil.wrapObject(map("a", "b", "num", 1)),
-            FieldMask.fromSet(new HashSet<>(asList(field("a")))),
+            fieldMask("a"),
             com.google.firebase.firestore.model.mutation.Precondition.exists(true));
     Mutation del = deleteMutation("baz/quux");
     Timestamp writeTime = Timestamp.now();

firebase-firestore/src/test/java/com/google/firebase/firestore/model/MutationTest.java

@@ -18,6 +18,7 @@
 import static com.google.firebase.firestore.testutil.TestUtil.deletedDoc;
 import static com.google.firebase.firestore.testutil.TestUtil.doc;
 import static com.google.firebase.firestore.testutil.TestUtil.field;
+import static com.google.firebase.firestore.testutil.TestUtil.fieldMask;
 import static com.google.firebase.firestore.testutil.TestUtil.key;
 import static com.google.firebase.firestore.testutil.TestUtil.map;
 import static com.google.firebase.firestore.testutil.TestUtil.mutationResult;
@@ -111,7 +112,7 @@ public void testDeletesValuesFromTheFieldMask() {
     Document baseDoc = doc("collection/key", 0, data);
 
     DocumentKey key = key("collection/key");
-    FieldMask mask = FieldMask.fromSet(new HashSet<>(Arrays.asList(field("foo.bar"))));
+    FieldMask mask = fieldMask("foo.bar");
     Mutation patch = new PatchMutation(key, ObjectValue.emptyObject(), mask, Precondition.NONE);
 
     MaybeDocument patchDoc = patch.applyToLocalView(baseDoc, baseDoc, Timestamp.now());

firebase-firestore/src/testUtil/java/com/google/firebase/firestore/testutil/TestUtil.java

@@ -74,6 +74,7 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -111,6 +112,14 @@ public static ByteString byteString(int... bytes) {
     return ByteString.copyFrom(primitive);
   }
 
+  public static FieldMask fieldMask(String... fields) {
+    FieldPath[] mask = new FieldPath[fields.length];
+    for (int i = 0; i < fields.length; i++) {
+      mask[i] = field(fields[i]);
+    }
+    return FieldMask.fromSet(new HashSet<>(Arrays.asList(mask)));
+  }
+
   public static final Map<String, Object> EMPTY_MAP = new HashMap<>();
 
   public static FieldValue wrap(Object value) {