Add new ParseQuery<>(query) for copying

Author: grantland

Parse/src/main/java/com/parse/ParseQuery.java

@@ -910,6 +910,17 @@ public ParseQuery(String theClassName) {
     this(new State.Builder<T>(theClassName));
   }
 
+  /**
+   * Constructs a copy of {@code query};
+   *
+   * @param query
+   *          The query to copy.
+   */
+  public ParseQuery(ParseQuery<T> query) {
+    this(new State.Builder<>(query.getBuilder()));
+    user = query.user;
+  }
+
   /* package */ ParseQuery(State.Builder<T> builder) {
     this.builder = builder;
   }
@@ -918,6 +929,12 @@ public ParseQuery(String theClassName) {
     return builder;
   }
 
+  /**
+   * Sets the user to be used for this query.
+   *
+   *
+   * The query will use the user if set, otherwise it will read the current user.
+   */
   /* package for tests */ ParseQuery<T> setUser(ParseUser user) {
     this.user = user;
     return this;

Parse/src/test/java/com/parse/ParseQueryTest.java

@@ -27,6 +27,7 @@
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertThat;
@@ -66,6 +67,25 @@ public void testConstructors() {
     assertSame(builder, query.getBuilder());
   }
 
+  @Test
+  public void testCopy() throws InterruptedException {
+    ParseQuery<ParseObject> query = new ParseQuery<>("TestObject");
+    query.setUser(new ParseUser());
+    query.whereEqualTo("foo", "bar");
+    ParseQuery.State.Builder<ParseObject> builder = query.getBuilder();
+    ParseQuery.State<ParseObject> state = query.getBuilder().build();
+
+    ParseQuery<ParseObject> queryCopy = new ParseQuery<>(query);
+    ParseQuery.State.Builder<ParseObject> builderCopy = queryCopy.getBuilder();
+    ParseQuery.State<ParseObject> stateCopy = queryCopy.getBuilder().build();
+
+    assertNotSame(query, queryCopy);
+    assertSame(query.getUserAsync(state).getResult(), queryCopy.getUserAsync(stateCopy).getResult());
+
+    assertNotSame(builder, builderCopy);
+    assertSame(state.constraints().get("foo"), stateCopy.constraints().get("foo"));
+  }
+
   // ParseUser#setUser is for tests only
   @Test
   public void testSetUser() throws ParseException {