Fix user input (#480)

* Add test for user input without value change

* Do not set userInput if there is no change

* Remove flag where it was added

src/vaadin-text-field-mixin.html

@@ -410,7 +410,9 @@
       if (!e.__fromClearButton) {
         this.__userInput = true;
       }
+
       this.value = e.target.value;
+      this.__userInput = false;
     }
 
     // NOTE(yuriy): Workaround needed for IE11 and Edge for proper displaying
@@ -467,7 +469,6 @@
       }
 
       if (this.__userInput) {
-        this.__userInput = false;
         return;
       } else if (newVal !== undefined) {
         this.inputElement.value = newVal;

test/text-field.html

@@ -439,6 +439,26 @@
 
       });
 
+      describe('value property', function() {
+        let textField, input;
+
+        beforeEach(function() {
+          textField = fixture(`default${fixtureName}`);
+          input = textField.inputElement;
+        });
+
+        it('should not consider updating the value as user input if the value is not changed', () => {
+          const event = new Event('input', {
+            bubbles: true,
+            cancelable: true
+          });
+          input.dispatchEvent(event);
+
+          textField.value = 'foo';
+          expect(input.value).to.equal('foo');
+        });
+      });
+
       describe(`events ${condition}`, function() {
         let textField, input;