react: make defaultProps Partial<P>

Added a test, which ensures that defaultProps are Partial

react/test/index.ts

@@ -689,3 +689,18 @@ type InputChangeEvent = React.ChangeEvent<HTMLInputElement>;
 type InputFormEvent = React.FormEvent<HTMLInputElement>;
 const changeEvent:InputChangeEvent = undefined as any;
 const formEvent:InputFormEvent = changeEvent;
+
+// defaultProps should be optional of props
+{
+    interface ComponentProps {
+        prop1: string;
+        prop2: string;
+        prop3?: string;
+    }
+    class ComponentWithDefaultProps extends React.Component<ComponentProps, void> {
+        static defaultProps = {
+            prop3: "default value",
+        };
+    }
+    const VariableWithAClass: React.ComponentClass<ComponentProps> = ComponentWithDefaultProps;
+}