fix(zod-validator): support transform (#1315)

* fix(zod-validator): support transform

* polish

.changeset/mean-rice-spend.md

@@ -0,0 +1,5 @@
+---
+'@hono/zod-validator': patch
+---
+
+fix: support transform

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])
       )

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)
+  })
+})