Fix

Author: mpppk

pkgs/typed-api-spec/src/fetch/index.t-test.ts

@@ -118,7 +118,6 @@ type ValidateUrlTestCase = [
   (async () => {
     const f = fetch as FetchT<"", JsonSpec>;
     const f2 = fetch as FetchT<"", Spec>;
-    const JSONT = JSON as JSONT;
     {
       // @ts-expect-error fetch requires input
       f();

pkgs/typed-api-spec/src/json/index.ts

@@ -20,22 +20,24 @@ type JsonPrimitive = string | number | boolean | null | Date;
 // eslint-disable-next-line @typescript-eslint/ban-types
 type InvalidJsonValue = undefined | Function | symbol | bigint;
 
-type JsonifyArrayElement<T> = T extends InvalidJsonValue ? null : Jsonify<T>;
-
 type JsonifyObject<T> = {
   [K in keyof T as K extends string
-    ? Jsonify<T[K]> extends infer ProcessedValue
-      ? ProcessedValue extends InvalidJsonValue
-        ? never
-        : K
-      : never
+    ? T[K] extends InvalidJsonValue
+      ? never
+      : K
     : never]: Jsonify<T[K]>;
 };
 
-// タプル型を保持するためのヘルパー型
-type JsonifyTuple<T extends readonly unknown[]> = {
-  [K in keyof T]: T[K] extends InvalidJsonValue ? null : Jsonify<T[K]>;
-};
+// タプル型を保持するためのヘルパー型 - 再帰の深さを制限
+type JsonifyTuple<T extends readonly unknown[]> = T extends [
+  infer First,
+  ...infer Rest,
+]
+  ? [
+      First extends InvalidJsonValue ? null : Jsonify<First>,
+      ...JsonifyTuple<Rest>,
+    ]
+  : [];
 
 type Jsonify<T> = T extends { toJSON(): infer R }
   ? Jsonify<R>
@@ -45,10 +47,10 @@ type Jsonify<T> = T extends { toJSON(): infer R }
       ? T
       : T extends InvalidJsonValue
         ? T
-        : T extends readonly [unknown, ...unknown[]] // T may be tuple
+        : T extends readonly [unknown, ...unknown[]] // タプル型の特別処理
           ? JsonifyTuple<T>
-          : T extends Array<infer E>
-            ? Array<JsonifyArrayElement<E>>
+          : T extends (infer E)[]
+            ? (E extends InvalidJsonValue ? null : Jsonify<E>)[]
             : T extends object
               ? JsonifyObject<T>
               : never;