fix: GDictionary absent values are returned as null, not undefined

Author: Benjamin-Dobell

scripts/jsb.editor/src/jsb.editor.codegen.ts

@@ -383,7 +383,7 @@ const TypeMutations: Record<string, TypeMutation> = {
             "proxy<Write extends boolean = false>(): Write extends true ? GDictionaryProxy<T> : GDictionaryReadProxy<T>",
             "",
             `${names.get_member("set_keyed")}<K extends keyof T>(key: K, value: T[K]): void`,
-            `${names.get_member("get_keyed")}<K extends keyof T>(key: K): T[K]`,
+            `${names.get_member("get_keyed")}<K extends keyof T>(key: K): UndefinedToNull<T[K]>`,
         ],
         property_overrides: {
             assign: mutate_parameter_type("dictionary", "T"),
@@ -394,10 +394,10 @@ const TypeMutations: Record<string, TypeMutation> = {
             find_key: chain_mutators(mutate_parameter_type("value", "T[keyof T]"), mutate_return_type("keyof T")), // This can be typed more accurately with a mapped type, but it seems excessive.
             erase: mutate_parameter_type("key", "keyof T"),
             keys: mutate_return_type("GArray<keyof T>"),
-            values: mutate_return_type("GArray<T[keyof T]>"),
+            values: mutate_return_type("GArray<UndefinedToNull<T[keyof T]>>"),
             duplicate: mutate_return_type("GDictionary<T>"),
-            get: chain_mutators(mutate_parameter_type("key", "K"), mutate_return_type("T[K]"), mutate_template("K extends keyof T")),
-            get_or_add: chain_mutators(mutate_parameter_type("key", "K"), mutate_parameter_type("default_", "T[K]"), mutate_template("K extends keyof T")),
+            get: chain_mutators(mutate_parameter_type("key", "K"), mutate_return_type("UndefinedToNull<T[K]>"), mutate_template("K extends keyof T")),
+            get_or_add: chain_mutators(mutate_parameter_type("key", "K"), mutate_return_type("UndefinedToNull<T[K]>"), mutate_parameter_type("default_", "T[K]"), mutate_template("K extends keyof T")),
             set: chain_mutators(mutate_parameter_type("key", "K"), mutate_parameter_type("value", "T[K]"), mutate_template("K extends keyof T")),
         }
     },

scripts/typings/godot.mix.d.ts

@@ -99,6 +99,8 @@ declare module "godot" {
     type ExtractValueKeys<T, V> = { [K in keyof T]: T[K] extends V ? K : never }[keyof T];
     type IfAny<T, Y, N> = 0 extends (1 & T) ? Y : N;
 
+    type UndefinedToNull<T> = T extends undefined ? null : T;
+
     /**
      * This namespace and the values within do not exist at runtime. They're declared here, for internal use only, as a
      * work-around for limitations of TypeScript's type system.