fix keyof method's recursion error when many keys used

library/src/methods/keyof/keyof.test-d.ts

@@ -6,6 +6,7 @@ import {
   type PicklistIssue,
   type PicklistSchema,
   string,
+  unknown,
 } from '../../schemas/index.ts';
 import type { InferInput, InferIssue, InferOutput } from '../../types/index.ts';
 import { keyof } from './keyof.ts';
@@ -52,4 +53,141 @@ describe('keyof', () => {
       expectTypeOf<InferIssue<Schema>>().toEqualTypeOf<PicklistIssue>();
     });
   });
+
+  test('should not trigger TS error for many keys', () => {
+    expectTypeOf(
+      keyof(
+        object({
+          k00: unknown(),
+          k01: unknown(),
+          k02: unknown(),
+          k03: unknown(),
+          k04: unknown(),
+          k05: unknown(),
+          k06: unknown(),
+          k07: unknown(),
+          k08: unknown(),
+          k09: unknown(),
+          k10: unknown(),
+          k11: unknown(),
+          k12: unknown(),
+          k13: unknown(),
+          k14: unknown(),
+          k15: unknown(),
+          k16: unknown(),
+          k17: unknown(),
+          k18: unknown(),
+          k19: unknown(),
+          k20: unknown(),
+          k21: unknown(),
+          k22: unknown(),
+          k23: unknown(),
+          k24: unknown(),
+          k25: unknown(),
+          k26: unknown(),
+          k27: unknown(),
+          k28: unknown(),
+          k29: unknown(),
+          k30: unknown(),
+          k31: unknown(),
+          k32: unknown(),
+          k33: unknown(),
+          k34: unknown(),
+          k35: unknown(),
+          k36: unknown(),
+          k37: unknown(),
+          k38: unknown(),
+          k39: unknown(),
+          k40: unknown(),
+          k41: unknown(),
+          k42: unknown(),
+          k43: unknown(),
+          k44: unknown(),
+          k45: unknown(),
+          k46: unknown(),
+          k47: unknown(),
+          k48: unknown(),
+          k49: unknown(),
+          k50: unknown(),
+          k51: unknown(),
+          k52: unknown(),
+          k53: unknown(),
+          k54: unknown(),
+          k55: unknown(),
+          k56: unknown(),
+          k57: unknown(),
+          k58: unknown(),
+          k59: unknown(),
+          k60: unknown(),
+        })
+      )
+    ).toEqualTypeOf<
+      PicklistSchema<
+        [
+          'k00',
+          'k01',
+          'k02',
+          'k03',
+          'k04',
+          'k05',
+          'k06',
+          'k07',
+          'k08',
+          'k09',
+          'k10',
+          'k11',
+          'k12',
+          'k13',
+          'k14',
+          'k15',
+          'k16',
+          'k17',
+          'k18',
+          'k19',
+          'k20',
+          'k21',
+          'k22',
+          'k23',
+          'k24',
+          'k25',
+          'k26',
+          'k27',
+          'k28',
+          'k29',
+          'k30',
+          'k31',
+          'k32',
+          'k33',
+          'k34',
+          'k35',
+          'k36',
+          'k37',
+          'k38',
+          'k39',
+          'k40',
+          'k41',
+          'k42',
+          'k43',
+          'k44',
+          'k45',
+          'k46',
+          'k47',
+          'k48',
+          'k49',
+          'k50',
+          'k51',
+          'k52',
+          'k53',
+          'k54',
+          'k55',
+          'k56',
+          'k57',
+          'k58',
+          'k59',
+          'k60',
+        ],
+        undefined
+      >
+    >();
+  });
 });

library/src/types/utils.ts

@@ -66,14 +66,21 @@ export type UnionToIntersect<TUnion> =
     : never;
 
 /**
- * Converts union to tuple type.
+ * Converts union to tuple type using an accumulator.
+ *
+ * For more information: {@link https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-5.html#tail-recursion-elimination-on-conditional-types}
  */
-export type UnionToTuple<TUnion> =
+type UnionToTupleHelper<TUnion, TResult extends unknown[]> =
   UnionToIntersect<
     TUnion extends never ? never : () => TUnion
   > extends () => infer TLast
-    ? [...UnionToTuple<Exclude<TUnion, TLast>>, TLast]
-    : [];
+    ? UnionToTupleHelper<Exclude<TUnion, TLast>, [TLast, ...TResult]>
+    : TResult;
+
+/**
+ * Converts union to tuple type.
+ */
+export type UnionToTuple<TUnion> = UnionToTupleHelper<TUnion, []>;
 
 /**
  * Checks if a type is `any`.