Style tests fixes

tns-core-modules/ui/core/properties.ts

@@ -507,10 +507,10 @@ export class CssProperty<T extends Style, U> implements definitions.CssProperty<
                 value = defaultValue;
                 delete this[sourceKey];
             } else {
-                this[sourceKey] = ValueSource.Css;
                 if (valueConverter && typeof value === "string") {
                     value = valueConverter(value);
                 }
+                this[sourceKey] = ValueSource.Css;
             }
 
             const currentValue: U = key in this ? this[key] : defaultValue;

tns-core-modules/ui/core/view-base.ts

@@ -123,6 +123,9 @@ export class ViewBase extends Observable implements ViewBaseDefinition {
     get style(): Style {
         return this._style;
     }
+    set style(value) {
+        throw new Error("View.style property is read-only.");
+    }
 
     get android(): any {
         return undefined;