Found workaround for microsoft/TypeScript/issues/21517 until it is fixed

Sebazzz · Sebazzz · commit d7f81a64f8f7 · 2018-02-01T18:50:31.000+01:00
diff --git a/src/App/js/AppFramework/Forms/ValidationMessage.ts b/src/App/js/AppFramework/Forms/ValidationMessage.ts
@@ -71,10 +71,11 @@ ko.bindingHandlers.validationProperty = {
                     element.setAttribute('required', 'required');
                 }
             } else {
+                const workaround = element as HTMLInputElement;
                 if (validationState) {
-                    element.classList.add('is-invalid');
+                    workaround.classList.add('is-invalid');
                 } else {
-                    element.classList.remove('is-invalid');
+                    workaround.classList.remove('is-invalid');
                 }
             }
         }

Original file line number	Diff line number	Diff line change
`@@ -71,10 +71,11 @@ ko.bindingHandlers.validationProperty = {`
`71`	`71`	`element.setAttribute('required', 'required');`
`72`	`72`	`}`
`73`	`73`	`} else {`
	`74`	`+ const workaround = element as HTMLInputElement;`
`74`	`75`	`if (validationState) {`
`75`		`- element.classList.add('is-invalid');`
	`76`	`+ workaround.classList.add('is-invalid');`
`76`	`77`	`} else {`
`77`		`- element.classList.remove('is-invalid');`
	`78`	`+ workaround.classList.remove('is-invalid');`
`78`	`79`	`}`
`79`	`80`	`}`
`80`	`81`	`}`