* Set default `Error` status code to 404
This is an appropriate default behavior because:
1. When the server encounters an error, the `err` property is set.
2. When the client-side application crashes, the `err` property is set.
This means the "only" way to render the `/_error` page without an error
is when a page is not found (special condition).
Fixes#6243Closes#5437
* Add new integration test for client side 404
* single quotes
* Remove unused variable
* Standard needs to go away
* Whoops
* Check for null status code in res and err
* Only check response for valid statusCode
* convert export default anonymous functions into named functions
* change examples to function declaration and split export in classes
* change NextHead name to Head and rename component
* Update README.md
I know I'm a moron for not understanding what's written in black on white, but... Maybe this will save someone an hour or two 😄
* Apply proposed changed
* Implement circular JSON err.sh link
* Add test for getInitialProps returning circular json
* Make test warn less
* Fix tests
* Add reference to original tests
Fixes#6117
I'm not entirely sure why we had this rule in the first place. I think for some tests related things when we didn't have a monorepo yet. However it could also be related to bundle sizes. I'll compare that when the build finishes.
The reason for #6117 is that we added `react-is` to the dependency tree of Next.js to check valid elements. react-redux uses hoist-non-react-statics which ships a different version of react-is in this case, one that has `ReactIs.isMemo`
Fixes#5363
I noticed this happening when making some changes on the nextjs.org/learn app. Basically we didn't apply updates when a warning was emitted from webpack. This would cause issues for users using eslint-loader or similar too.