Issue with next/link in Next 12.2.0

Hello!

I’ve noticed that after upgrade to newest version of Next 12.2.0 (released 3 days ago) there is an issue with tests utilising Next Link.

import Link from "next/link"
...
jest.mock("next/router", () => require("next-router-mock"));
jest.mock("next/dist/client/router", () => require("next-router-mock"));
...
it("", () => {
  const { getByText } = render(<div><Link href={"/foo"}>Foo</Link></div>);
  const foo = getByText("Foo");
  fireEvent.click(foo);
});
...

test fails with following error:

TypeError: Cannot read properties of null (reading ‘push’) 57 | fireEvent.click(foo);

After Next downgrade to previous stable version (12.1.6) everything works fine.

I am on the latest version of next-router-mock

I suspected that there may be some changes in the paths or refactor of Link component in the 12.2.0 release but didn’t found anything like that in the PR. Do you have any clue what’s going on?

Best!

[Damo1155]

Thanks for the input.

Just to note, the above code resolves most of the issue but it still seems like you need both of the following:

jest.mock("next/dist/client/router", () => require("next-router-mock"));

jest.mock("next/dist/shared/lib/router-context", () => {
  const { createContext } = require("react");
  const router = require("next-router-mock").default;
  const RouterContext = createContext(router);
  return { RouterContext };
});

Not having line one continues to break the tests but keeping line one passes them all.

[scottrippey]

I’ve started work on this router-context concept, but it’s not quite complete, and I’m not sure if it’s a long-term solution. I’ll post here as I update.

I’m attempting to get in contact with Vercel directly, so that I can make some headway on a long-term solution.