Repository: vercel/next.js
Pull request: feat: provide nextVersion to modifyConfig adapter hook

For providers that either don't manage or allow for custom build commands, checking Next.js version in their builders is not reliable. Especially for providers that already have existing support there needs to be very reliable way to only apply certain configuration adjustments for supported versions of Adapters API.

So this adds `nextVersion` to `modifyConfig` to allow that. It also brings parity to this hook (`onBuildComplete` already does receive `nextVersion`. 

Corresponding adjustments for docs (just types update) prepared in https://github.com/vercel/next.js/compare/canary...pieh:next.js:docs/nextVersion-in-adapter-modifyConfig

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Changed files:
filename: packages/next/src/build/adapter/build-complete.ts
patch: @@ -335,6 +335,10 @@ export interface NextAdapter {
     config: NextConfigComplete,
     ctx: {
       phase: PHASE_TYPE
+      /**
+       * nextVersion is the current version of Next.js being used
+       */
+      nextVersion: string
     }
   ) => Promise<NextConfigComplete> | NextConfigComplete
   onBuildComplete?: (ctx: {

filename: packages/next/src/server/config.ts
patch: @@ -1442,6 +1442,7 @@ async function applyModifyConfig(
 
       config = await adapterMod.modifyConfig(config, {
         phase,
+        nextVersion: process.env.__NEXT_VERSION as string,
       })
     }
   }