Add hasControl method (#10035)

src/ui/map.js

@@ -555,6 +555,23 @@ class Map extends Camera {
         return this;
     }
 
+    /**
+     * Checks if a control exists on the map.
+     *
+     * @param {IControl} control The {@link IControl} to check.
+     * @returns {boolean} True if map contains control.
+     * @example
+     * // Define a new navigation control.
+     * var navigation = new mapboxgl.NavigationControl();
+     * // Add zoom and rotation controls to the map.
+     * map.addControl(navigation);
+     * // Check that the navigation control exists on the map.
+     * map.hasControl(navigation);
+     */
+    hasControl(control: IControl) {
+        return this._controls.indexOf(control) > -1;
+    }
+
     /**
      * Resizes the map according to the dimensions of its
      * `container` element.

test/unit/ui/map.test.js

@@ -1019,6 +1019,22 @@ test('Map', (t) => {
 
     });
 
+    t.test('#hasControl', (t) => {
+        const map = createMap(t);
+        function Ctrl() {}
+        Ctrl.prototype = {
+            onAdd(_) {
+                return window.document.createElement('div');
+            }
+        };
+
+        const control = new Ctrl();
+        t.equal(map.hasControl(control), false, 'Reference to control is not found');
+        map.addControl(control);
+        t.equal(map.hasControl(control), true, 'Reference to control is found');
+        t.end();
+    });
+
     t.test('#project', (t) => {
         const map = createMap(t);
         t.deepEqual(map.project([0, 0]), {x: 100, y: 100});