Add QueryResultOptionalPopulated helper type

src/types/EntityPrimitiveOrId.ts

@@ -1,3 +1,9 @@
 import type { Entity } from '../Entity';
 
-export type EntityPrimitiveOrId<T extends Entity> = Extract<NonNullable<T>, Entity> extends Entity ? Exclude<NonNullable<T>, Entity> | Pick<T, 'id'> : T;
+export type EntityPrimitiveOrId<T> = T extends []
+  ? T extends (infer U)[]
+    ? EntityPrimitiveOrId<U>[]
+    : T // Unable to determine array type, so return original
+  : Extract<NonNullable<T>, Entity> extends undefined
+  ? T
+  : Exclude<NonNullable<T>, Entity> | Pick<Extract<NonNullable<T>, Entity>, 'id'>;

src/types/QueryResultOptionalPopulated.ts

@@ -0,0 +1,15 @@
+import type { Entity } from '../Entity';
+
+import type { EntityPrimitiveOrId } from './EntityPrimitiveOrId';
+import type { QueryResult } from './QueryResult';
+
+/**
+ * Allows a QueryResult type with specific properties optionally populated. If the property is populated, only the id property is needed
+ */
+export type QueryResultOptionalPopulated<T extends Entity, K extends keyof T> = Omit<QueryResult<T>, K> & {
+  [P in K]-?: T[P] extends []
+    ? undefined extends T[P] // If property is not an array
+      ? EntityPrimitiveOrId<T[P]> | null // If the property is originally optional, include null as a possible value type
+      : EntityPrimitiveOrId<T[P]> // Otherwise, use the TPropertyType
+    : EntityPrimitiveOrId<T[P]>; // Otherwise return an array of items
+};

src/types/index.ts

@@ -13,3 +13,4 @@ export * from './PickFunctions';
 export * from './Populated';
 export * from './QueryResult';
 export * from './QueryResultPopulated';
+export * from './QueryResultOptionalPopulated';