Use regex lexer for gathering named groups from has (#23626)

This is a follow-up to #23588 to update to use a regex lexer to gather the named regex groups instead of attempting to gather them through executing the regex since it can fail to gather the regex groups when they are using specific matching. This also ensures we don't pass the value as a segment when value is defined and it doesn't use a capture group. Additional tests are added to cover these cases and documentation updated to reflect this. 

Closes: #23415

## Bug

- [x] Related issues linked using `fixes #number`
- [x] Integration tests added

## Documentation / Examples

- [x] Make sure the linting passes

.eslintignore

@@ -16,4 +16,5 @@ packages/next-codemod/**/*.js
 packages/next-codemod/**/*.d.ts
 packages/next-env/**/*.d.ts
 test/integration/async-modules/**
-test-timings.json
+test-timings.json
+packages/next/lib/regexr/**/*

docs/api-reference/next.config.js/headers.md

@@ -195,6 +195,9 @@ module.exports = {
           {
             type: 'query',
             key: 'page',
+            // the page value will not be available in the
+            // header key/values since value is provided and
+            // doesn't use a named capture group e.g. (?<page>home)
             value: 'home',
           },
           {

docs/api-reference/next.config.js/redirects.md

@@ -135,6 +135,9 @@ module.exports = {
           {
             type: 'query',
             key: 'page',
+            // the page value will not be available in the
+            // destination since value is provided and doesn't
+            // use a named capture group e.g. (?<page>home)
             value: 'home',
           },
           {

docs/api-reference/next.config.js/rewrites.md

@@ -214,6 +214,9 @@ module.exports = {
           {
             type: 'query',
             key: 'page',
+            // the page value will not be available in the
+            // destination since value is provided and doesn't
+            // use a named capture group e.g. (?<page>home)
             value: 'home',
           },
           {
@@ -222,7 +225,7 @@ module.exports = {
             value: 'true',
           },
         ],
-        destination: '/:path*/:page',
+        destination: '/:path*/home',
       },
       // if the header `x-authorized` is present and
       // contains a matching value, this rewrite will be applied

packages/next/lib/load-custom-routes.ts

@@ -8,7 +8,10 @@ import {
 } from '../next-server/lib/constants'
 import { execOnce } from '../next-server/lib/utils'
 import * as Log from '../build/output/log'
-import { getSafeParamName } from '../next-server/lib/router/utils/prepare-destination'
+// @ts-ignore
+import Lexer from 'next/dist/compiled/regexr-lexer/lexer'
+// @ts-ignore
+import lexerProfiles from 'next/dist/compiled/regexr-lexer/profiles'
 
 export type RouteHas =
   | {
@@ -336,20 +339,16 @@ function checkCustomRoutes(
 
         if (hasItem.value) {
           const matcher = new RegExp(`^${hasItem.value}$`)
-          const matches = matcher.exec('')
-
-          if (matches) {
-            if (matches.groups) {
-              Object.keys(matches.groups).forEach((groupKey) => {
-                const safeKey = getSafeParamName(groupKey)
-
-                if (safeKey && matches.groups![groupKey]) {
-                  hasSegments.add(safeKey)
-                }
-              })
-            } else {
-              hasSegments.add(hasItem.key || 'host')
-            }
+          const lexer = new Lexer()
+          lexer.profile = lexerProfiles.js
+          lexer.parse(`/${matcher.source}/`)
+
+          Object.keys(lexer.namedGroups).forEach((groupKey) => {
+            hasSegments.add(groupKey)
+          })
+
+          if (hasItem.type === 'host') {
+            hasSegments.add('host')
           }
         }
       }