feat: Remove undefined from Jsonlike (#98)

src/type-utils.ts

@@ -16,7 +16,7 @@ export type IsEqual<T, U> = (<G>() => G extends T ? 1 : 2) extends <G>() => G ex
 
 type IsNotJsonableError<T> = Invalid<`${Extract<T, string>} is not Json-like`> & {};
 
-type NotJsonable = ((...arguments_: any[]) => any) | undefined | symbol | RegExp | Function;
+type NotJsonable = ((...arguments_: any[]) => any) | symbol | RegExp | Function;
 
 type NeverToNull<T> = IsNever<T> extends true ? null : T;
 
@@ -66,8 +66,10 @@ export type Jsonlike<T, CastBehavior extends JsonCastBehavior> = T extends Posit
   ? JsonlikeList<WritableDeep<T>, CastBehavior>
   : T extends object
   ? {
-      [K in keyof T]: [T[K]] extends [NotJsonable] | [never] ? IsNotJsonableError<K> : Jsonlike<T[K], CastBehavior>;
-    } // JsonifyObject recursive call for its children
+      [K in keyof T]: [T[K]] extends [NotJsonable] | [never] ? IsNotJsonableError<K> : Jsonlike<T[K], CastBehavior>; // JsonifyObject recursive call for its children
+    }
+  : T extends undefined
+  ? T
   : IsNotJsonableError<'Passed value'>;
 
 export interface Invalid<msg = any> {

test/test_schema.gen.json

@@ -467,5 +467,5 @@
       }
     }
   },
-  "$hash": "09d762cb9c53f4338c7374249078c983ab9ddf1a0814f98d7854a4e15f301e7b__v2.0.0"
+  "$hash": "09d762cb9c53f4338c7374249078c983ab9ddf1a0814f98d7854a4e15f301e7b__v2.0.0-rc.1"
 }

test/typed-fastify.test-d.ts

@@ -722,52 +722,55 @@ expectType<Service<Params>>({
   },
 });
 
-function verifyJsonlike<
-  Input,
-  Expected extends Jsonlike<Input, DoNotCastToPrimitive>,
-  DoNotCastToPrimitive extends 'cast' | 'combine',
->() {}
-
-verifyJsonlike<
-  {
-    a: string;
-    b: {
-      toJSON(): number;
-    };
-    c: {
-      toJSON(): {
-        toJSON(): string;
+function jsonLike<Input, DoNotCastToPrimitive extends 'cast' | 'combine'>() {
+  return {} as unknown as Jsonlike<Input, DoNotCastToPrimitive>;
+}
+expectType<{
+  a?: string;
+  aa?: string | null | undefined;
+  b: number;
+  c: string;
+  d: string;
+  A: Invalid<'A is not Json-like'>;
+  B: Invalid<'B is not Json-like'>;
+  C: Invalid<'C is not Json-like'>;
+  D?: undefined;
+}>(
+  jsonLike<
+    {
+      a: string | undefined;
+      aa?: string | null | undefined;
+      b: {
+        toJSON(): number;
       };
-    };
-    d: Date;
-    A: RegExp;
-    B: Function;
-    C: () => 1;
-    D: undefined;
-  },
-  {
-    a: string;
-    b: number;
-    c: string;
-    d: string;
-    A: Invalid<'A is not Json-like'>;
-    B: Invalid<'B is not Json-like'>;
-    C: Invalid<'C is not Json-like'>;
-    D: Invalid<'D is not Json-like'>;
-  },
-  'cast'
->();
-
-verifyJsonlike<
-  {
-    a: Date;
-    b: Number;
-    A: RegExp;
-  },
-  {
-    a: Date;
-    b: number;
-    A: Invalid<'A is not Json-like'>;
-  },
-  'combine'
->();
+      c: {
+        toJSON(): {
+          toJSON(): string;
+        };
+      };
+      d: Date;
+      A: RegExp;
+      B: Function;
+      C: () => 1;
+      D: undefined;
+    },
+    'cast'
+  >(),
+);
+
+expectType<{
+  a: Date | string;
+  aa?: Date | string;
+  b: number;
+  A: Invalid<'A is not Json-like'>;
+}>(
+  jsonLike<
+    {
+      a: Date;
+      aa: Date | undefined;
+      b: Number;
+      A: RegExp;
+    },
+    'combine'
+  >(),
+);