* Add identifier to NEXT_DATA for gs(s)p

* Apply suggestions from code review
Co-Authored-By: NJoe Haddad <joe.haddad@zeit.co>

* fix lint

* apply lint fix
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Throw a NoFallbackError instead of returning

* Replace invariant
Co-authored-by: NJJ Kasper <jj@jjsweb.site>

* Prefetch SSG Data

* Update packages/next/client/page-loader.js
Co-Authored-By: NJJ Kasper <jj@jjsweb.site>

* Revert router.ts

* Revert link.tsx

* undo change

* mimmic existing

* simplify

* Prefetch href and asPath

* fix load

* dedupe prefetchAs

* Inject script tag on hover

* comment prefetchAs

* minify code

* introduce lazy files

* Add some breathing room

* correct default type

* Prefetch non-dynamic data

* Prefetch dynamic route data

* Fix size test

* Humanize code

* add tests

* Disable code

* Only generate modern version in modern mode

* Extract function helper

* add comments

* Filter out dynamic route to simplify manifest size

* add test
Co-authored-by: NJJ Kasper <jj@jjsweb.site>

* Correctly pass preview data

* remove todo

* re-do change

* fix types

* Prevent regression

* Remove Dead Code from Next Server

* remove options

* trigger

* Separate Low Priority Files from Main Files

* Fix tests

* Extract getStaticPaths helper

* Extract sendPayload and prepareServerlessUrl

* Remove erroneously included file

* Rename getServerProps to getServerSideProps

* Remove unstable_ prefix from new methods

* Add error when legacy methods are detected

* Add legacy methods for babel transform

* Add unstable_getServerSideProps also

* Apply suggestions from code review
Co-Authored-By: NJoe Haddad <joe.haddad@zeit.co>

* Update types import
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Ability to Disable SSG Fallback

* Throw error when value is missing

* Fix existing tests

* Adjust error message

* Do not render fallback at build time for `fallback: false` page

* Fix existing fallback behavior

* fix build

* fix version

* fix some tests

* Fix last test

* Add docs for get static paths

* Add explicit mode tests

* test for fallback error message

* Make sure to show error when url prop is returned for a page

* Update test and handle undefined pageProps

* Handle empty props

* Apply suggestions from code review
Co-Authored-By: NTim Neutkens <tim@timneutkens.nl>

* Update tests

* Update to not add url prop for SSG/SSP pages

* Update errsh for reserved prop

* Update errsh wording some more

* Update tests and to warn instead of error

* Update reserved prop warning

* Include page in url prop warning
Co-authored-by: NTim Neutkens <tim@timneutkens.nl>
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Add calling getStaticPaths in development before showing fallback

* Move staticPathsWorker to next-dev-server

* Make sure to clear require cache in worker process

* bump

* Remove staticPathsCache member

* Update numWorkers for staticPathsWorker

* Preview Mode Should Not Cache

* add import

* fix import

* add tests

* Add real serverless mode tests

* Add error messages for dynamic SSG page without getStaticPaths

* Update error check

* Update test file

* Update another test file

* Adjust
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Add err.sh for getStaticProps error

* Prettify error
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Clean up landed experimental flags

* Remove check for experimental flags from build too

* Remove /_errors/404 in favor of /404

* Remove unneeded check for pathname

* Update test paths

* Fix test

* Update test

* Remove test for disabled config

* Set pages404 always to true
Co-authored-by: NJoe Haddad <timer150@gmail.com>
Co-authored-by: NJJ Kasper <jj@jjsweb.site>

* Fixed pathname check in router

Remove the query portion of the URL when checking paths

* Updated change and added trial test

* Update test
Co-authored-by: NJJ Kasper <jj@jjsweb.site>

* Add NextApiHandler type

* Fix formatting
Co-authored-by: NJoe Haddad <timer150@gmail.com>

Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Remove ts-ignore where possible

And replace by typecasts

* More accurate types

* bend cliententries in a correct shape earlier on

* comment becomes unnecessary

* add webpack overload to allow for the next.js use case

* Avoid changing public interface
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Speculate Navigations for Client-Side JS

* add tests

* avoid desctructure

This adds a `isFallback` property to detect if the page is being rendered in "fallback" mode or normal mode.
Accessed via the `useRouter()` hook.

---

Closes #10527

* Check next.config.js settings

* Add tests

* test package.json case too

* Make sure to encode pathname for custom-route destination

* Add tests to security test suite

* Clean up async in next-server

* fix case when err is null

* Refactor how components are loaded
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Adjust SSG Loading Behavior

* Update expected preview behavior

* Rename two corrections

* Only use skeleton in production for now

* Fix "should SSR SPR page correctly" test

* fix tests

* fix trailing comment letter

* disable test for now

* checkpoint: api impl

* Add support for tryGetPreviewData

* snapshot: server(less) support

* Add X-Prerender-Bypass-Mode header support

* Pass preview data to getStaticProps call

* add TODO

* setPreviewData

* 100k iterations

* Handle jwt error

* Write out preview values

* forgot file

* set preview props

* Send preview props

* add preview props

* Pass around more data

* update yarn lock

* Fail on Invalid Prerender Manifest

* Make Missing Prerender Manifest Fatal

* fix ts errors

* fix test

* Fix setting cookies + maxage

* Secure is not needed as we encrypt necessary data

* Set on domain root

* Set cookie max ages

* Render a fallback on-demand for non-dynamic pages

* Test preview mode

* remove old build

* remove snapshots

* Add serverless tests

* use afterAll

* Remove object assigns

* fix cookie spread

* add comment

* Update next-server routes order for expected priority

* Update router to allow disabling page routes

* Fix headers having check: true behavior when they should not
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Fail on Invalid Prerender Manifest

* Make Missing Prerender Manifest Fatal

* fix test

* Add error message when rewriting to dynamic SSG page

* Update comment
Co-authored-by: NJoe Haddad <timer150@gmail.com>

* Add paths field for unstable_getStaticPaths

* Make sure to specify page in getStaticPaths errors

* Add initial SSG fallback handling

* Remove extra changes and update fallback handling

* Remove extra timeout for testing

* Update SSG tests in dynamic-routing suite

* Add racing to decide between rendering fallback and data

* Update size-limit test

* Update comment

* Make sure to follow correct route change order

* Make comment more verbose for racing

* Revert getStaticData to only return Promise

* Make sure to update URL on fallback

* Add retrying for data, de-dupe initial fallback request, and merge fallback replace

* Update to add preload for fallback pages data

* Add test for data preload link

* Use pre-built fallback in production mode

* Remove preload link for fallback from _document

* Update to make sure fallback is rendered correctly for serverless