test(datetime): add unit tests to make sure we return a string when we should (#11431)

* test(datetime): add e2e test with no format provided

* test(datetime): add test to check output is a string

* test(datetime): add e2e test with no format provided

* test(datetime): add test to check output is a string

* test(datetime): add unit tests to make sure we return a string when we should

src/components/datetime/test/basic/pages/root-page/root-page.html

@@ -109,4 +109,9 @@
     <ion-datetime displayFormat="HH:mm:ss" [(ngModel)]="time"></ion-datetime>
   </ion-item>
 
+  <ion-item>
+    <ion-label>No displayFormat: {{noFormatDate}}</ion-label>
+    <ion-datetime [(ngModel)]="noFormatDate"></ion-datetime>
+  </ion-item>
+
 </ion-content>

src/components/datetime/test/datetime.spec.ts

@@ -139,6 +139,39 @@ describe('DateTime', () => {
 
       expect(columns[1].options[12].disabled).toEqual(true);
     });
+
+    it('should always return a string', () => {
+      datetime.monthValues = '6,7,8';
+      datetime.dayValues = '01,02,03,04,05,06,08,09,10, 11, 12, 13, 31';
+      datetime.yearValues = '2014,2015';
+
+      datetime.registerOnChange((value: string) => {
+        expect(value).toEqual(jasmine.any(String));
+      });
+    });
+
+    it('should return a string when setValue is passed an object', zoned(() => {
+      const dateTimeData = {
+        hour: {
+          text: '12',
+          value: 12,
+        },
+        minute: {
+          text: '09',
+          value: 9,
+        },
+        ampm: {
+          text: 'pm',
+          value: 'pm',
+        },
+      };
+
+      datetime.setValue(dateTimeData);
+
+      datetime.registerOnChange((value: string) => {
+        expect(value).toEqual(jasmine.any(String));
+      });
+    }));
   });
 
   describe('writeValue', () => {