fix: Troubleshooting a bug in which an empty array is deduced as an a…

…rray of Dates unconditionally #4
kakasoo · Jan 26, 2025 · 6f95218 · 6f95218
1 parent a363ced
commit 6f95218
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Showing 2 changed files with 17 additions and 2 deletions.
diff --git a/src/types/DeepStrictUnbrand.ts b/src/types/DeepStrictUnbrand.ts
@@ -39,8 +39,9 @@ namespace DeepStrictUnbrand {
  * type Example3 = DeepStrictUnbrand<Array<string & { __brand: 'email' }>>; // Array<string>
  * ```
  */
-export type DeepStrictUnbrand<T> =
-  T extends Array<Date>
+export type DeepStrictUnbrand<T> = T extends []
+  ? []
+  : T extends Array<Date>
     ? Array<Date>
     : T extends Array<infer I extends object>
       ? Array<DeepStrictUnbrand<I>>

diff --git a/test/types/DeepStrictUnbrand.ts b/test/types/DeepStrictUnbrand.ts
@@ -3,6 +3,20 @@ import test from 'node:test';
 import typia from 'typia';
 import { DeepStrictUnbrand, Equal } from '../../src';
 
+test('If it is empty array', () => {
+  type Question = DeepStrictUnbrand<[]>;
+  type Answer = Equal<Question, []>;
+
+  ok(typia.random<Answer>());
+});
+
+test('If it is empty array', () => {
+  type Question = DeepStrictUnbrand<[][]>;
+  type Answer = Equal<Question, [][]>;
+
+  ok(typia.random<Answer>());
+});
+
 test('If it is not a brand type', () => {
   type Question = DeepStrictUnbrand<string | Date>;
   type Answer = Equal<Question, string | Date>;