DevTools causes hydration errrors on page refresh in Next.js

[raleigh9123]

I thought I had done something wonky in my app when these errors started appearing. I rolled back on some changes and learned that they appeared when I refresh the page that has the component imported.

I am working within a Blitz.js app which is built on Next.js (I am unsure, but am lead to believe that this is a problem within Next.js?)

The

component used by default in the Blitz.js installation is a little bit of a beast, in my opinion, and I added a couple more details to allow me to pass a custom prop to the child inputs.

My Form Component

// src / core / components / Form.tsx
// --> COMPONENT <-

// Node Modules Imports
import { useState, ReactNode, PropsWithoutRef, Children, cloneElement } from "react"
import { FormProvider, useForm, UseFormProps } from "react-hook-form"
import { zodResolver } from "@hookform/resolvers/zod"
import { z } from "zod"
import { DevTool } from "@hookform/devtools"

// TS Declarations
export interface FormProps<S extends z.ZodType<any, any>>
  extends Omit<PropsWithoutRef<JSX.IntrinsicElements["form"]>, "onSubmit"> {
  /** All your form fields */
  children?: ReactNode
  /** Text to display in the submit button */
  schema?: S
  onSubmit: (values: z.infer<S>) => Promise<void | OnSubmitResult>
  initialValues?: UseFormProps<z.infer<S>>["defaultValues"]
  formtype?: string
}

interface OnSubmitResult {
  FORM_ERROR?: string
  [prop: string]: any
}

export const FORM_ERROR = "FORM_ERROR"

export function Form<S extends z.ZodType<any, any>>({
  children,
  schema,
  initialValues,
  onSubmit,
  formtype = "submit",
  ...props
}: FormProps<S>) {
  const ctx = useForm<z.infer<S>>({
    mode: "onChange",
    resolver: schema ? zodResolver(schema) : undefined,
    defaultValues: initialValues,
  })
  const [formError, setFormError] = useState<string | null>(null)

  let isProd = process.env.NODE_ENV === "production"

  return (
    <FormProvider {...ctx}>
      <form
        onSubmit={ctx.handleSubmit(async (values) => {
          const result = (await onSubmit(values)) || {}
          for (const [key, value] of Object.entries(result)) {
            if (key === FORM_ERROR) {
              setFormError(value)
            } else {
              ctx.setError(key as any, {
                type: "submit",
                message: value,
              })
            }
          }
        })}
        className="space-y-4"
        {...props}
      >
        {/* Form fields supplied as children are rendered here */}
        {Children.map(children, (child) =>
          cloneElement(child as React.ReactElement, { formtype })
        )}

        {formError && (
          <div role="alert" className="text-salmon-500 text-center">
            {formError}
          </div>
        )}


      </form>
      {!isProd && <DevTool control={ctx.control} /> }

    </FormProvider>
  )
}

export default Form

Again, the hydration errors ONLY occur when I refresh the page. They are listed in the following screenshot. I have not tried anything as a solution, but they do not appear when I remove the component.

The following is my package.json dependencies:

"dependencies": {
    "@blitzjs/auth": "2.0.0-beta.19",
    "@blitzjs/next": "2.0.0-beta.19",
    "@blitzjs/rpc": "2.0.0-beta.19",
    "@headlessui/react": "1.7.7",
    "@heroicons/react": "2.0.13",
    "@hookform/error-message": "2.0.1",
    "@hookform/resolvers": "2.9.10",
    "@prisma/client": "4.8.0",
    "blitz": "2.0.0-beta.19",
    "framer-motion": "7.10.2",
    "next": "12.2.5",
    "node-device-detector": "2.0.9",
    "postmark": "3.0.14",
    "prisma": "4.8.0",
    "react": "18.2.0",
    "react-dom": "18.2.0",
    "react-hook-form": "7.40.0",
    "react-icons": "4.7.1",
    "zod": "3.20.2"
  },
  "devDependencies": {
    "@hookform/devtools": "4.3.0",
    "@next/bundle-analyzer": "12.0.8",
    "@tailwindcss/forms": "0.5.3",
    "@testing-library/jest-dom": "5.16.3",
    "@testing-library/react": "13.4.0",
    "@testing-library/react-hooks": "8.0.1",
    "@types/jest": "29.2.2",
    "@types/node": "18.11.9",
    "@types/preview-email": "2.0.1",
    "@types/react": "18.0.25",
    "@typescript-eslint/eslint-plugin": "5.30.5",
    "autoprefixer": "10.4.13",
    "eslint": "8.27.0",
    "eslint-config-next": "12.3.1",
    "eslint-config-prettier": "8.5.0",
    "husky": "8.0.2",
    "jest": "29.3.0",
    "jest-environment-jsdom": "29.3.0",
    "lint-staged": "13.0.3",
    "postcss": "8.4.19",
    "prettier": "^2.7.1",
    "prettier-plugin-prisma": "4.4.0",
    "pretty-quick": "3.1.3",
    "preview-email": "3.0.7",
    "tailwindcss": "3.2.4",
    "ts-jest": "28.0.7",
    "typescript": "^4.8.4"
  },

[Nurou]

@raleigh9123 I've the same issue in a next.js app caused by DevTools. I use the following dynamic import workaround for now:

const DevT = dynamic(
  () =>
    import('@hookform/devtools').then((module) => {
      return module.DevTool
    }),
  { ssr: false },
)

[adamwdennis]

@Nurou 's answer worked for me! Thank you!!

Here's a slightly updated, typescript-compatible version of it that worked for me (hope it can save a few minutes for others like me who enjoy having a painful eslint config 😄 ):

import dynamic from 'next/dynamic';
const DevT: React.ElementType = dynamic(
  () => import('@hookform/devtools').then((module) => module.DevTool),
  { ssr: false }
);

Then, (like @Nurou insinuates), I can use it like so:

...
return (
  <FormProvider {...methods}>
    <DevT control={methods.control} placement="top-left" />
    ...
  </FormProvider>
)

[mohaimenkhalid]

@adamwdennis cool.. working..