Allow readonly arrays in resource Relations declaration

Author: CarsonF

src/common/resource.dto.ts

@@ -80,7 +80,10 @@ export type ResourceShape<T> = AbstractClassType<T> & {
   // Default should probably be considered the props on Resource class.
   BaseNodeProps?: string[];
   Relations?: Thunk<
-    Record<string, ResourceShape<any> | [ResourceShape<any>] | undefined>
+    Record<
+      string,
+      ResourceShape<any> | readonly [ResourceShape<any>] | undefined
+    >
   >;
   /**
    * Define this resource as being a child of another.
@@ -397,7 +400,7 @@ export type SecuredPropsPlusExtraKey<
 /* eslint-disable @typescript-eslint/ban-types -- {} is used to mean non-nullable, it's not an empty interface */
 
 export type ExtraPropsFromRelationsKey<T extends ResourceShape<any>> = {
-  [R in RelKey<T>]: RelOf<T>[R] extends Array<infer U>
+  [R in RelKey<T>]: RelOf<T>[R] extends ReadonlyArray<infer U>
     ? U extends ResourceShape<any>
       ? U['Parent'] extends {}
         ? never
@@ -411,7 +414,7 @@ export type ExtraPropsFromRelationsKey<T extends ResourceShape<any>> = {
 }[RelKey<T>];
 
 export type ChildSinglesKey<T extends ResourceShape<any>> = {
-  [R in RelKey<T>]: RelOf<T>[R] extends any[]
+  [R in RelKey<T>]: RelOf<T>[R] extends readonly any[]
     ? never
     : RelOf<T>[R] extends ResourceShape<any>
     ? RelOf<T>[R]['Parent'] extends {}
@@ -421,7 +424,7 @@ export type ChildSinglesKey<T extends ResourceShape<any>> = {
 }[RelKey<T>];
 
 export type ChildListsKey<T extends ResourceShape<any>> = {
-  [R in RelKey<T>]: RelOf<T>[R] extends Array<infer U>
+  [R in RelKey<T>]: RelOf<T>[R] extends ReadonlyArray<infer U>
     ? U extends ResourceShape<any>
       ? U['Parent'] extends {}
         ? R