Ability to clear constraints for a given key

Author: natario1

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

@@ -527,6 +527,12 @@ private Builder<T> whereSatifiesAnyOf(List<QueryConstraints> constraints) {
         return this;
       }
 
+      // Used by clear
+      /* package */ Builder<T> clear(String key) {
+        where.remove(key);
+        return this;
+      }
+
       //endregion
 
       //region Order
@@ -2087,6 +2093,18 @@ public String getClassName() {
     return builder.getClassName();
   }
 
+  /**
+   * Clears constraints related to the given key, if any was set previously.
+   * Order, includes and selected keys are not affected by this operation.
+   *
+   * @param key key to be cleared from current constraints.
+   * @return this, so you can chain this call.
+   */
+  public ParseQuery<T> clear(String key) {
+    builder.clear(key);
+    return this;
+  }
+
   /**
    * Turn on performance tracing of finds.
    * <p/>

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

@@ -563,6 +563,18 @@ public void testWhereWithinKilometers() throws Exception {
     verifyCondition(query, "key", "$maxDistance", 100.0 / ParseGeoPoint.EARTH_MEAN_RADIUS_KM);
   }
 
+  @Test
+  public void testClear() throws Exception {
+    ParseQuery<ParseObject> query = new ParseQuery<>("Test");
+    query.whereEqualTo("key", "value");
+    query.whereEqualTo("otherKey", "otherValue");
+    verifyCondition(query, "key", "value");
+    verifyCondition(query, "otherKey", "otherValue");
+    query.clear("key");
+    verifyCondition(query, "key", null);
+    verifyCondition(query, "otherKey", "otherValue"); // still.
+  }
+
   @Test
   public void testOr() throws Exception {
     ParseQuery<ParseObject> query = new ParseQuery<>("Test");
@@ -684,6 +696,13 @@ public void testSkip() throws Exception {
     assertEquals(5, query.getSkip());
   }
 
+  private static void verifyCondition(ParseQuery query, String key, Object value) {
+    // We generate a state to verify the content of the builder
+    ParseQuery.State state = query.getBuilder().build();
+    ParseQuery.QueryConstraints queryConstraints = state.constraints();
+    assertEquals(value, queryConstraints.get(key));
+  }
+
   private static void verifyCondition(
       ParseQuery query, String key, String conditionKey, Object value) {
     // We generate a state to verify the content of the builder