Ensure has segments are allowed in destination

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

@@ -8,6 +8,7 @@ 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'
 
 export type RouteHas =
   | {
@@ -325,6 +326,34 @@ function checkCustomRoutes(
       }
       sourceTokens = tokens
     }
+    const hasSegments = new Set<string>()
+
+    if (route.has) {
+      for (const hasItem of route.has) {
+        if (!hasItem.value && hasItem.key) {
+          hasSegments.add(hasItem.key)
+        }
+
+        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')
+            }
+          }
+        }
+      }
+    }
 
     // make sure no unnamed patterns are attempted to be used in the
     // destination as this can cause confusion and is not allowed
@@ -369,15 +398,16 @@ function checkCustomRoutes(
             for (const token of destTokens!) {
               if (
                 typeof token === 'object' &&
-                !sourceSegments.has(token.name)
+                !sourceSegments.has(token.name) &&
+                !hasSegments.has(token.name as string)
               ) {
                 invalidDestSegments.add(token.name)
               }
             }
 
             if (invalidDestSegments.size) {
               invalidParts.push(
-                `\`destination\` has segments not in \`source\` (${[
+                `\`destination\` has segments not in \`source\` or \`has\` (${[
                   ...invalidDestSegments,
                 ].join(', ')})`
               )

packages/next/next-server/lib/router/utils/prepare-destination.ts

@@ -9,7 +9,7 @@ type Params = { [param: string]: any }
 
 // ensure only a-zA-Z are used for param names for proper interpolating
 // with path-to-regexp
-const getSafeParamName = (paramName: string) => {
+export const getSafeParamName = (paramName: string) => {
   let newParamName = ''
 
   for (let i = 0; i < paramName.length; i++) {

test/integration/custom-routes/next.config.js

@@ -149,6 +149,16 @@ module.exports = {
           ],
           destination: '/with-params?host=1',
         },
+        {
+          source: '/has-rewrite-5',
+          has: [
+            {
+              type: 'query',
+              key: 'hasParam',
+            },
+          ],
+          destination: '/:hasParam',
+        },
       ],
       beforeFiles: [
         {

test/integration/custom-routes/test/index.test.js

@@ -692,6 +692,22 @@ const runTests = (isDev = false) => {
     expect(res2.status).toBe(404)
   })
 
+  it('should pass has segment for rewrite correctly', async () => {
+    const res1 = await fetchViaHTTP(appPort, '/has-rewrite-5')
+    expect(res1.status).toBe(404)
+
+    const res = await fetchViaHTTP(appPort, '/has-rewrite-5', {
+      hasParam: 'with-params',
+    })
+
+    expect(res.status).toBe(200)
+    const $ = cheerio.load(await res.text())
+
+    expect(JSON.parse($('#query').text())).toEqual({
+      hasParam: 'with-params',
+    })
+  })
+
   it('should match has rewrite correctly before files', async () => {
     const res1 = await fetchViaHTTP(appPort, '/hello')
     expect(res1.status).toBe(200)
@@ -1509,6 +1525,17 @@ const runTests = (isDev = false) => {
               regex: '^\\/has-rewrite-4$',
               source: '/has-rewrite-4',
             },
+            {
+              destination: '/:hasParam',
+              has: [
+                {
+                  key: 'hasParam',
+                  type: 'query',
+                },
+              ],
+              regex: normalizeRegEx('^\\/has-rewrite-5$'),
+              source: '/has-rewrite-5',
+            },
           ],
           fallback: [],
         },

test/integration/invalid-custom-routes/test/index.test.js

@@ -542,7 +542,7 @@ const runTests = () => {
     const stderr = await getStderr()
 
     expect(stderr).toContain(
-      `\`destination\` has segments not in \`source\` (id) for route {"source":"/feedback/:type","destination":"/feedback/:id"}`
+      `\`destination\` has segments not in \`source\` or \`has\` (id) for route {"source":"/feedback/:type","destination":"/feedback/:id"}`
     )
   })
 }