Error: NextRouter was not mounted
Shivan M.
—The Problem
When using the useRouter hook in Next.js 13 or later, you may encounter the following error:
Error: NextRouter was not mounted
This error can occur in one of two ways:
- When a component uses the
useRouterhook outside of a Next.js application, or when a router is rendered outside of a Next.js application - like during unit testing. - When trying to use the
useRouterhook from thenext/routerpackage when using the App Directory. This is because the App Router (fromnext/navigation) has a different behavior from theuseRouterhook used inpages.
The Solution
Ensure you are using the correct useRouter hook. If you are using the App Directory, check that the useRouter hook is imported from next/navigation and not from next/router.
When using the useRouter hook from next/navigation, use the following guidelines:
- Instead of
pathname, use theusePathname()hook. - Instead of the
queryobject, use theuseSearchParams()hook.
Mock next/navigation When Writing Unit Tests
next/navigation When Writing Unit TestsThe above error can also occur when using the useRouter hook from next/navigation in unit tests. It might be a good idea to use the next-router-mock package to mock it.
Ensure you mock the new hooks, usePathname() and useSearchParams(), for example:
const nextRouterMock = require('next-router-mock') jest.mock('next/navigation', () => { const { useRouter } = nextRouterMock const usePathname = () => { const router = useRouter() return router.pathname } const useSearchParams = () => { const router = useRouter() return new URLSearchParams(router.query) } return { useRouter, usePathname, useSearchParams } })
- Sentry BlogCommon Errors in Next.js and How to Resolve Them
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