From c6a16ab7aa8fba2403d4294e7673f96796020c65 Mon Sep 17 00:00:00 2001
From: Yusuke Wada <yusuke@kamawada.com>
Date: Sat, 19 Jul 2025 10:20:40 +0900
Subject: [PATCH] fix(zod-validator): support transform (#1315)

* fix(zod-validator): support transform

* polish
---
 .changeset/mean-rice-spend.md         |  5 ++++
 packages/zod-validator/src/index.ts   |  2 +-
 packages/zod-validator/src/v4.test.ts | 36 +++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/mean-rice-spend.md

diff --git a/.changeset/mean-rice-spend.md b/.changeset/mean-rice-spend.md
new file mode 100644
index 00000000..1097c238
--- /dev/null
+++ b/.changeset/mean-rice-spend.md
@@ -0,0 +1,5 @@
+---
+'@hono/zod-validator': patch
+---
+
+fix: support transform
diff --git a/packages/zod-validator/src/index.ts b/packages/zod-validator/src/index.ts
index 4689e6d8..90d29a4a 100644
--- a/packages/zod-validator/src/index.ts
+++ b/packages/zod-validator/src/index.ts
@@ -73,7 +73,7 @@ export const zValidator = <
     if ((target === 'header' && '_def' in schema) || (target === 'header' && '_zod' in schema)) {
       // create an object that maps lowercase schema keys to lowercase
       // @ts-expect-error the schema is a Zod Schema
-      const schemaKeys = Object.keys(schema.shape)
+      const schemaKeys = Object.keys('in' in schema ? schema.in.shape : schema.shape)
       const caseInsensitiveKeymap = Object.fromEntries(
         schemaKeys.map((key) => [key.toLowerCase(), key])
       )
diff --git a/packages/zod-validator/src/v4.test.ts b/packages/zod-validator/src/v4.test.ts
index 884e6410..1a0fdff7 100644
--- a/packages/zod-validator/src/v4.test.ts
+++ b/packages/zod-validator/src/v4.test.ts
@@ -464,3 +464,39 @@ describe('With options + validationFunction', () => {
     })
   })
 })
+
+describe('Transform', () => {
+  const schema = z
+    .object({
+      'user-agent': z.string(),
+    })
+    .transform((data) => ({
+      userAgent: data['user-agent'],
+    }))
+
+  const zValidatorHeader = zValidator('header', schema)
+
+  const app = new Hono()
+
+  app.post('/test', zValidatorHeader, async (c) => {
+    const header = c.req.valid('header')
+    return c.json(header)
+  })
+
+  it('Should return 400 response', async () => {
+    const res = await app.request('/test', {
+      method: 'POST',
+    })
+    expect(res.status).toBe(400)
+  })
+
+  it('Should return 200 response', async () => {
+    const res = await app.request('/test', {
+      method: 'POST',
+      headers: {
+        'user-agent': 'my-agent',
+      },
+    })
+    expect(res.status).toBe(200)
+  })
+})