feat(radio-button) fix thrown error on dismiss solves #6466

ionic/components/radio/radio-button.ts

@@ -155,6 +155,8 @@ export class RadioButton {
    */
   ngOnDestroy() {
     this._form.deregister(this);
+    if (this._group) {
       this._group.remove(this);
     }
+  }
 }

ionic/components/radio/test/radio.spec.ts

@@ -86,12 +86,32 @@ export function run() {
       });
 
     });
+  });
+
+  describe('RadioButton', () => {
+
+    describe('ngOnDestroy', () => {
+      it('should work without a group', () => {
+        let rb1 = createRadioButton(false);
+        expect(() => rb1.ngOnDestroy()).not.toThrowError();
+      });
+
+      it('should remove button from group if part of a radio group', () => {
+        let rb1 = createRadioButton();
+        spyOn(rg, 'remove');
+        rb1.ngOnDestroy();
+        expect(rg.remove).toHaveBeenCalledWith(rb1);
+      });
+
+    });
+
+  });
 
   let rg: RadioGroup;
   let form: Form;
 
-    function createRadioButton() {
+  function createRadioButton(shouldIncludeGroup = true) {
-      return new RadioButton(form, null, rg);
+    return new RadioButton(form, null, shouldIncludeGroup? rg : null);
   }
 
   function mockRenderer(): any {
@@ -110,6 +130,4 @@ export function run() {
     rg = new RadioGroup(mockRenderer(), mockElementRef());
     form = new Form();
   });
-
-  });
 }