fix(validator): don't return a FormData if formData is cached (#3067)

* fix(validator): don't return a FormData if formData is cached

* fixed typo

* test the value

src/validator/validator.test.ts

@@ -910,6 +910,24 @@ describe('Clone Request object', () => {
       }
     )
 
+    app.post(
+      '/cached',
+      async (c, next) => {
+        await c.req.parseBody()
+        await next()
+      },
+      validator('form', (value) => {
+        if (value instanceof FormData) {
+          throw new Error('The value should not be a FormData')
+        }
+        return value
+      }),
+      (c) => {
+        const v = c.req.valid('form')
+        return c.json(v)
+      }
+    )
+
     it('Should not throw the error with c.req.parseBody()', async () => {
       const body = new FormData()
       body.append('foo', 'bar')
@@ -920,6 +938,18 @@ describe('Clone Request object', () => {
       const res = await app.request(req)
       expect(res.status).toBe(200)
     })
+
+    it('Should not be an instance of FormData if the formData is cached', async () => {
+      const body = new FormData()
+      body.append('foo', 'bar')
+      const req = new Request('http://localhost/cached', {
+        method: 'POST',
+        body: body,
+      })
+      const res = await app.request(req)
+      expect(res.status).toBe(200)
+      expect(await res.json()).toEqual({ foo: 'bar' })
+    })
   })
 })
 

src/validator/validator.ts

@@ -83,33 +83,35 @@ export const validator = <
           break
         }
 
+        let formData: FormData
+
         if (c.req.bodyCache.formData) {
-          value = await c.req.bodyCache.formData
-          break
+          formData = await c.req.bodyCache.formData
+        } else {
+          try {
+            const arrayBuffer = await c.req.arrayBuffer()
+            formData = await bufferToFormData(arrayBuffer, contentType)
+            c.req.bodyCache.formData = formData
+          } catch (e) {
+            let message = 'Malformed FormData request.'
+            message += e instanceof Error ? ` ${e.message}` : ` ${String(e)}`
+            throw new HTTPException(400, { message })
+          }
         }
 
-        try {
-          const arrayBuffer = await c.req.arrayBuffer()
-          const formData = await bufferToFormData(arrayBuffer, contentType)
-          const form: BodyData<{ all: true }> = {}
-          formData.forEach((value, key) => {
-            if (key.endsWith('[]')) {
-              if (form[key] === undefined) {
-                form[key] = [value]
-              } else if (Array.isArray(form[key])) {
-                ;(form[key] as unknown[]).push(value)
-              }
-            } else {
-              form[key] = value
+        const form: BodyData<{ all: true }> = {}
+        formData.forEach((value, key) => {
+          if (key.endsWith('[]')) {
+            if (form[key] === undefined) {
+              form[key] = [value]
+            } else if (Array.isArray(form[key])) {
+              ;(form[key] as unknown[]).push(value)
             }
-          })
-          value = form
-          c.req.bodyCache.formData = formData
-        } catch (e) {
-          let message = 'Malformed FormData request.'
-          message += e instanceof Error ? ` ${e.message}` : ` ${String(e)}`
-          throw new HTTPException(400, { message })
-        }
+          } else {
+            form[key] = value
+          }
+        })
+        value = form
         break
       }
       case 'query':