Improved forwardRef with generics explainer

Author: mattpocock

src/08-advanced-patterns/65-forward-ref-with-generics.explainer.3.ts

@@ -0,0 +1,46 @@
+import { Equal, Expect } from "../helpers/type-utils";
+
+type TableProps<T> = {
+  data: T[];
+  renderRow: (item: T) => React.ReactNode;
+};
+
+export const Table = <T,>(props: TableProps<T>) => {
+  return null;
+};
+
+type FC<Props> = {
+  (arg: Props): React.ReactNode;
+  // Try uncommenting this - and it works!
+  someOtherThing?: string;
+};
+
+const removeInference = <Props,>(component: FC<Props>) => {
+  return component;
+};
+
+const TableWithoutInference = removeInference(Table);
+
+const Parent = () => {
+  return (
+    <>
+      <TableWithoutInference
+        data={["123"]}
+        renderRow={(row) => {
+          // Without inference, this is 'unknown'
+          type test = Expect<Equal<typeof row, string>>;
+          return <div>123</div>;
+        }}
+      ></TableWithoutInference>
+
+      <Table
+        data={["123"]}
+        renderRow={(row) => {
+          // With inference, it's 'string'
+          type test = Expect<Equal<typeof row, string>>;
+          return <div>123</div>;
+        }}
+      ></Table>
+    </>
+  );
+};