Fix branded types in record

Author: colinhacks

packages/zod/src/v4/classic/tests/brand.test.ts

@@ -55,3 +55,11 @@ test("$branded", () => {
 
   expectTypeOf<typeof a>().toEqualTypeOf<z.core.$ZodBranded<z.ZodString, "a">>();
 });
+
+test("branded record", () => {
+  const recordWithBrandedNumberKeys = z.record(z.string().brand("SomeBrand"), z.number());
+  type recordWithBrandedNumberKeys = z.infer<typeof recordWithBrandedNumberKeys>;
+  expectTypeOf<recordWithBrandedNumberKeys>().toEqualTypeOf<
+    Record<string & z.core.$brand<"SomeBrand">, number | undefined>
+  >();
+});

packages/zod/src/v4/core/schemas.ts

@@ -2324,31 +2324,31 @@ export interface $ZodRecordDef extends $ZodTypeDef {
   valueType: $ZodType;
 }
 
-type $InferZodRecordOutput<
+export type $InferZodRecordOutput<
   Key extends $ZodRecordKey = $ZodRecordKey,
   Value extends $ZodType = $ZodType,
 > = undefined extends Key["_zod"]["values"]
-  ? string extends Key["_zod"]["output"]
-    ? Record<Key["_zod"]["output"], core.output<Value>>
-    : number extends Key["_zod"]["output"]
-      ? Record<Key["_zod"]["output"], core.output<Value>>
-      : symbol extends Key["_zod"]["output"]
-        ? Record<Key["_zod"]["output"], core.output<Value>>
-        : Partial<Record<Key["_zod"]["output"], core.output<Value>>>
-  : Record<Key["_zod"]["output"], core.output<Value>>;
-
-type $InferZodRecordInput<
+  ? string extends core.output<Key>
+    ? Record<core.output<Key>, core.output<Value>>
+    : number extends core.output<Key>
+      ? Record<core.output<Key>, core.output<Value>>
+      : symbol extends core.output<Key>
+        ? Record<core.output<Key>, core.output<Value>>
+        : Partial<Record<core.output<Key>, core.output<Value>>>
+  : Record<core.output<Key>, core.output<Value>>;
+
+export type $InferZodRecordInput<
   Key extends $ZodRecordKey = $ZodRecordKey,
   Value extends $ZodType = $ZodType,
 > = undefined extends Key["_zod"]["values"]
-  ? string extends Key["_zod"]["input"]
-    ? Record<Key["_zod"]["input"], Value["_zod"]["input"]>
-    : number extends Key["_zod"]["input"]
-      ? Record<Key["_zod"]["input"], Value["_zod"]["input"]>
-      : symbol extends Key["_zod"]["input"]
-        ? Record<Key["_zod"]["input"], Value["_zod"]["input"]>
-        : Partial<Record<Key["_zod"]["input"], Value["_zod"]["input"]>>
-  : Record<Key["_zod"]["input"], Value["_zod"]["input"]>;
+  ? string extends core.input<Key>
+    ? Record<core.input<Key>, core.input<Value>>
+    : number extends core.input<Key>
+      ? Record<core.input<Key>, core.input<Value>>
+      : symbol extends core.input<Key>
+        ? Record<core.input<Key>, core.input<Value>>
+        : Partial<Record<core.input<Key>, core.input<Value>>>
+  : Record<core.input<Key>, core.input<Value>>;
 
 export interface $ZodRecordInternals<Key extends $ZodRecordKey = $ZodRecordKey, Value extends $ZodType = $ZodType>
   extends $ZodTypeInternals<$InferZodRecordOutput<Key, Value>, $InferZodRecordInput<Key, Value>> {

play.ts

@@ -1,23 +1,5 @@
 import { z } from "zod/v4";
 
 z;
-import { discriminatedUnion, literal, object, pipe, string, transform } from "zod/v4-mini";
-
-const schemaWithPipe = discriminatedUnion("type", [
-  object({
-    type: pipe(
-      transform((v) => v),
-      literal("a")
-    ),
-    a: string(),
-  }),
-  object({
-    type: pipe(
-      transform((v) => v),
-      literal("b")
-    ),
-    b: string(),
-  }),
-]);
-
-schemaWithPipe.safeParse({ type: "a", a: "abc" });
+const recordWithBrandedNumberKeys = z.record(z.number().brand("SomeBrand"), z.number());
+type recordWithBrandedNumberKeys = z.infer<typeof recordWithBrandedNumberKeys>;