Add test

tests/cases/fourslash/partialUnionPropertyCacheInconsistentErrors.ts

@@ -0,0 +1,45 @@
+/// <reference path="fourslash.ts" />
+
+// @strict: true
+// @lib: esnext
+
+//// interface ComponentOptions<Props> {
+////   setup?: (props: Props) => void;
+////   name?: string;
+//// }
+//// 
+//// interface FunctionalComponent<P> {
+////   (props: P): void;
+//// }
+//// 
+//// type ConcreteComponent<Props> =
+////   | ComponentOptions<Props>
+////   | FunctionalComponent<Props>;
+//// 
+//// type Component<Props = {}> = ConcreteComponent<Props>;
+//// 
+//// type WithInstallPlugin = { _prefix?: string };
+//// 
+//// 
+//// /**/
+//// export function withInstall<C extends Component, T extends WithInstallPlugin>(
+////   component: C | C[],
+////   target?: T,
+//// ): string {
+////   const componentWithInstall = (target ?? component) as T;
+////   const components = Array.isArray(component) ? component : [component];
+//// 
+////   const { name } = components[0];
+////   if (name) {
+////     return name;
+////   }
+//// 
+////   return "";
+//// }
+
+verify.noErrors();
+
+goTo.marker();
+edit.insert("type C = Component['name']");
+
+verify.noErrors();