fix: Fixed to return 400 response when the request body is not FormData

packages/conform-validator/src/utils.ts

@@ -1,9 +1,13 @@
 import type { Context } from 'hono'
 import { bufferToFormData } from 'hono/utils/buffer'
 
+// ref: https://github.com/honojs/hono/blob/a63bcfd6fba66297d8234c21aed8a42ac00711fe/src/validator/validator.ts#L27-L28
+const multipartRegex = /^multipart\/form-data(; boundary=[A-Za-z0-9'()+_,\-./:=?]+)?$/
+const urlencodedRegex = /^application\/x-www-form-urlencoded$/
+
 export const getFormDataFromContext = async (ctx: Context): Promise<FormData> => {
   const contentType = ctx.req.header('Content-Type')
-  if (!contentType) {
+  if (!contentType || !(multipartRegex.test(contentType) || urlencodedRegex.test(contentType))) {
     return new FormData()
   }
 

packages/conform-validator/test/common.test.ts

@@ -0,0 +1,35 @@
+import { Hono } from 'hono'
+import { z } from 'zod'
+import { parseWithZod } from '@conform-to/zod'
+import { conformValidator } from '../src'
+
+describe('Validate common processing', () => {
+  const app = new Hono()
+  const schema = z.object({ name: z.string() })
+  const route = app.post(
+    '/author',
+    conformValidator((formData) => parseWithZod(formData, { schema })),
+    (c) => {
+      const submission = c.req.valid('form')
+      const value = submission.value
+      return c.json({ success: true, message: `my name is ${value.name}` })
+    }
+  )
+
+  describe('When the request body is empty', () => {
+    it('Should return 400 response', async () => {
+      const res = await route.request('/author', { method: 'POST' })
+      expect(res.status).toBe(400)
+    })
+  })
+
+  describe('When the request body is not FormData', () => {
+    it('Should return 400 response', async () => {
+      const res = await route.request('/author', {
+        method: 'POST',
+        body: JSON.stringify({ name: 'Space Cat!' }),
+      })
+      expect(res.status).toBe(400)
+    })
+  })
+})