additional polish and QoL features

server/internal/utils/types.d.ts

@@ -0,0 +1,7 @@
+export type FilterConditionally<Source, Condition> = Pick<
+  Source,
+  { [K in keyof Source]: Source[K] extends Condition ? K : never }[keyof Source]
+>;
+export type KeyOfType<T, V> = keyof {
+  [P in keyof T as T[P] extends V ? P : never]: any;
+};