From 5b7f61dcaae62164d5b88701ec073246dcb5a212 Mon Sep 17 00:00:00 2001
From: Sheraff <fpellet@ensc.fr>
Date: Wed, 21 Jan 2026 22:31:27 +0100
Subject: [PATCH 1/5] refactor(router-core): skip full matchRoutesInternal for
 Link's buildLocation, use simple getMatchedRoutes

---
 packages/router-core/src/router.ts | 44 ++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 11 deletions(-)

diff --git a/packages/router-core/src/router.ts b/packages/router-core/src/router.ts
index f0c20f4170b..a341febc3c4 100644
--- a/packages/router-core/src/router.ts
+++ b/packages/router-core/src/router.ts
@@ -1775,16 +1775,38 @@ export class RouterCore<
         params: nextParams,
       }).interpolatedPath
 
-      const { matches: destMatches, rawParams } = this.matchRoutesInternal(
-        { pathname: interpolatedNextTo } as ParsedLocation,
-        { _buildLocation: true },
-      )
-      const destRoutes = destMatches.map(
-        (d) => this.looseRoutesById[d.routeId]!,
-      )
-
-      // Check if any match indicates global not found
-      const globalNotFoundMatch = destMatches.find((m) => m.globalNotFound)
+      // Use lightweight getMatchedRoutes instead of matchRoutesInternal
+      // This avoids creating full match objects (AbortController, ControlledPromise, etc.)
+      // which are expensive and not needed for buildLocation
+      const destMatchResult = this.getMatchedRoutes(interpolatedNextTo)
+      const destRoutes = destMatchResult.matchedRoutes as Array<AnyRoute>
+      const rawParams = destMatchResult.routeParams
+
+      // Compute globalNotFoundRouteId using the same logic as matchRoutesInternal
+      const isGlobalNotFound = destMatchResult.foundRoute
+        ? destMatchResult.foundRoute.path !== '/' &&
+          destMatchResult.routeParams['**']
+        : trimPathRight(interpolatedNextTo)
+
+      let globalNotFoundRouteId: string | undefined
+      if (isGlobalNotFound) {
+        if (this.options.notFoundRoute) {
+          globalNotFoundRouteId = this.options.notFoundRoute.id
+        } else if (this.options.notFoundMode !== 'root') {
+          for (let i = destRoutes.length - 1; i >= 0; i--) {
+            const route = destRoutes[i]!
+            if (route.children) {
+              globalNotFoundRouteId = route.id
+              break
+            }
+          }
+          if (!globalNotFoundRouteId) {
+            globalNotFoundRouteId = rootRouteId
+          }
+        } else {
+          globalNotFoundRouteId = rootRouteId
+        }
+      }
 
       // If there are any params, we need to stringify them
       if (Object.keys(nextParams).length > 0) {
@@ -1877,7 +1899,7 @@ export class RouterCore<
         routes: destRoutes,
         params: snapshotParams,
         searchStr,
-        globalNotFoundRouteId: globalNotFoundMatch?.routeId,
+        globalNotFoundRouteId,
       })
 
       // Create the full path of the location

From 5704974ad1598b2bde3f87a0d7383fc62210418b Mon Sep 17 00:00:00 2001
From: Sheraff <fpellet@ensc.fr>
Date: Thu, 22 Jan 2026 08:25:52 +0100
Subject: [PATCH 2/5] update unit tests, useParams not called on link building,
 only nav

---
 packages/react-router/tests/useParams.test.tsx | 8 ++++----
 packages/solid-router/tests/useParams.test.tsx | 8 ++++----
 packages/vue-router/tests/useParams.test.tsx   | 8 ++++----
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/packages/react-router/tests/useParams.test.tsx b/packages/react-router/tests/useParams.test.tsx
index ec54c5e1fb1..3c15aade319 100644
--- a/packages/react-router/tests/useParams.test.tsx
+++ b/packages/react-router/tests/useParams.test.tsx
@@ -189,7 +189,7 @@ test('useParams must return parsed result if applicable.', async () => {
 
   expect(window.location.pathname).toBe('/posts/category_first')
   expect(await screen.findByTestId('post-category-heading')).toBeInTheDocument()
-  expect(mockedfn).toHaveBeenCalledTimes(1)
+  expect(mockedfn).not.toHaveBeenCalled()
 
   mockedfn.mockClear()
   await act(() => fireEvent.click(firstPostLink))
@@ -213,7 +213,7 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(renderedPost.category).toBe('one')
   expect(paramCategoryValue.textContent).toBe('one')
   expect(paramPostIdValue.textContent).toBe('1')
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).toHaveBeenCalledTimes(1)
   expect(allCategoryLink).toBeInTheDocument()
 
   mockedfn.mockClear()
@@ -224,7 +224,7 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(window.location.pathname).toBe('/posts/category_all')
   expect(await screen.findByTestId('post-category-heading')).toBeInTheDocument()
   expect(secondPostLink).toBeInTheDocument()
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).not.toHaveBeenCalled()
 
   mockedfn.mockClear()
   await act(() => fireEvent.click(secondPostLink))
@@ -246,5 +246,5 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(renderedPost.category).toBe('two')
   expect(paramCategoryValue.textContent).toBe('all')
   expect(paramPostIdValue.textContent).toBe('2')
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).toHaveBeenCalledTimes(1)
 })
diff --git a/packages/solid-router/tests/useParams.test.tsx b/packages/solid-router/tests/useParams.test.tsx
index 291e76d0f81..b94df57c6ae 100644
--- a/packages/solid-router/tests/useParams.test.tsx
+++ b/packages/solid-router/tests/useParams.test.tsx
@@ -188,7 +188,7 @@ test('useParams must return parsed result if applicable.', async () => {
 
   expect(window.location.pathname).toBe('/posts/category_first')
   expect(await screen.findByTestId('post-category-heading')).toBeInTheDocument()
-  expect(mockedfn).toHaveBeenCalledTimes(1)
+  expect(mockedfn).not.toHaveBeenCalled()
 
   mockedfn.mockClear()
   await waitFor(() => fireEvent.click(firstPostLink))
@@ -211,7 +211,7 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(renderedPost.category).toBe('one')
   expect(paramCategoryValue.textContent).toBe('one')
   expect(paramPostIdValue.textContent).toBe('1')
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).toHaveBeenCalledTimes(1)
   expect(allCategoryLink).toBeInTheDocument()
 
   mockedfn.mockClear()
@@ -222,7 +222,7 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(window.location.pathname).toBe('/posts/category_all')
   expect(await screen.findByTestId('post-category-heading')).toBeInTheDocument()
   expect(secondPostLink).toBeInTheDocument()
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).not.toHaveBeenCalled()
 
   mockedfn.mockClear()
   await waitFor(() => fireEvent.click(secondPostLink))
@@ -244,5 +244,5 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(renderedPost.category).toBe('two')
   expect(paramCategoryValue.textContent).toBe('all')
   expect(paramPostIdValue.textContent).toBe('2')
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).toHaveBeenCalledTimes(1)
 })
diff --git a/packages/vue-router/tests/useParams.test.tsx b/packages/vue-router/tests/useParams.test.tsx
index 897e43928f0..07da6c02d14 100644
--- a/packages/vue-router/tests/useParams.test.tsx
+++ b/packages/vue-router/tests/useParams.test.tsx
@@ -193,7 +193,7 @@ test('useParams must return parsed result if applicable.', async () => {
 
   expect(window.location.pathname).toBe('/posts/category_first')
   expect(await screen.findByTestId('post-category-heading')).toBeInTheDocument()
-  expect(mockedfn).toHaveBeenCalledTimes(1)
+  expect(mockedfn).not.toHaveBeenCalled()
 
   mockedfn.mockClear()
   await waitFor(() => fireEvent.click(firstPostLink))
@@ -216,7 +216,7 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(renderedPost.category).toBe('one')
   expect(paramCategoryValue.textContent).toBe('one')
   expect(paramPostIdValue.textContent).toBe('1')
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).toHaveBeenCalledTimes(1)
   expect(allCategoryLink).toBeInTheDocument()
 
   mockedfn.mockClear()
@@ -227,7 +227,7 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(window.location.pathname).toBe('/posts/category_all')
   expect(await screen.findByTestId('post-category-heading')).toBeInTheDocument()
   expect(secondPostLink).toBeInTheDocument()
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).not.toHaveBeenCalled()
 
   mockedfn.mockClear()
   await waitFor(() => fireEvent.click(secondPostLink))
@@ -249,5 +249,5 @@ test('useParams must return parsed result if applicable.', async () => {
   expect(renderedPost.category).toBe('two')
   expect(paramCategoryValue.textContent).toBe('all')
   expect(paramPostIdValue.textContent).toBe('2')
-  expect(mockedfn).toHaveBeenCalledTimes(2)
+  expect(mockedfn).toHaveBeenCalledTimes(1)
 })

From df7decf09cc2c4e94b063b56edb32236b035a581 Mon Sep 17 00:00:00 2001
From: Sheraff <fpellet@ensc.fr>
Date: Thu, 22 Jan 2026 15:14:12 +0100
Subject: [PATCH 3/5] factorize a little

---
 packages/router-core/src/router.ts | 50 +++++++++++++-----------------
 1 file changed, 22 insertions(+), 28 deletions(-)

diff --git a/packages/router-core/src/router.ts b/packages/router-core/src/router.ts
index a341febc3c4..6fbbdc3dd1d 100644
--- a/packages/router-core/src/router.ts
+++ b/packages/router-core/src/router.ts
@@ -1330,22 +1330,9 @@ export class RouterCore<
         }
       }
 
-      globalNotFoundRouteId = (() => {
-        if (!isGlobalNotFound) {
-          return undefined
-        }
-
-        if (this.options.notFoundMode !== 'root') {
-          for (let i = matchedRoutes.length - 1; i >= 0; i--) {
-            const route = matchedRoutes[i]!
-            if (route.children) {
-              return route.id
-            }
-          }
-        }
-
-        return rootRouteId
-      })()
+      globalNotFoundRouteId = isGlobalNotFound
+        ? findGlobalNotFoundRouteId(this.options.notFoundMode, matchedRoutes)
+        : undefined
     }
 
     const matches: Array<AnyRouteMatch> = []
@@ -1792,19 +1779,11 @@ export class RouterCore<
       if (isGlobalNotFound) {
         if (this.options.notFoundRoute) {
           globalNotFoundRouteId = this.options.notFoundRoute.id
-        } else if (this.options.notFoundMode !== 'root') {
-          for (let i = destRoutes.length - 1; i >= 0; i--) {
-            const route = destRoutes[i]!
-            if (route.children) {
-              globalNotFoundRouteId = route.id
-              break
-            }
-          }
-          if (!globalNotFoundRouteId) {
-            globalNotFoundRouteId = rootRouteId
-          }
         } else {
-          globalNotFoundRouteId = rootRouteId
+          globalNotFoundRouteId = findGlobalNotFoundRouteId(
+            this.options.notFoundMode,
+            destRoutes,
+          )
         }
       }
 
@@ -3173,3 +3152,18 @@ function applySearchMiddleware({
   // Start applying middlewares
   return applyNext(0, search)
 }
+
+function findGlobalNotFoundRouteId(
+  notFoundMode: 'root' | 'fuzzy' | undefined,
+  routes: ReadonlyArray<AnyRoute>,
+) {
+  if (notFoundMode !== 'root') {
+    for (let i = routes.length - 1; i >= 0; i--) {
+      const route = routes[i]!
+      if (route.children) {
+        return route.id
+      }
+    }
+  }
+  return rootRouteId
+}

From 7de43c42c5590ec932e41f4c42626b37ff62720f Mon Sep 17 00:00:00 2001
From: Sheraff <fpellet@ensc.fr>
Date: Thu, 22 Jan 2026 15:17:27 +0100
Subject: [PATCH 4/5] remove type cast

---
 packages/router-core/src/router.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/router-core/src/router.ts b/packages/router-core/src/router.ts
index 6fbbdc3dd1d..f3061298901 100644
--- a/packages/router-core/src/router.ts
+++ b/packages/router-core/src/router.ts
@@ -1766,7 +1766,7 @@ export class RouterCore<
       // This avoids creating full match objects (AbortController, ControlledPromise, etc.)
       // which are expensive and not needed for buildLocation
       const destMatchResult = this.getMatchedRoutes(interpolatedNextTo)
-      const destRoutes = destMatchResult.matchedRoutes as Array<AnyRoute>
+      const destRoutes = destMatchResult.matchedRoutes
       const rawParams = destMatchResult.routeParams
 
       // Compute globalNotFoundRouteId using the same logic as matchRoutesInternal
@@ -3046,7 +3046,7 @@ function applySearchMiddleware({
 }: {
   search: any
   dest: BuildNextOptions
-  destRoutes: Array<AnyRoute>
+  destRoutes: ReadonlyArray<AnyRoute>
   _includeValidateSearch: boolean | undefined
 }) {
   const allMiddlewares =

From 3e7e9a0f132f10e3803d8221c7dd9b274123e83b Mon Sep 17 00:00:00 2001
From: Sheraff <fpellet@ensc.fr>
Date: Thu, 22 Jan 2026 15:33:50 +0100
Subject: [PATCH 5/5] fix deprecated not found route handling

---
 packages/router-core/src/router.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/router-core/src/router.ts b/packages/router-core/src/router.ts
index f3061298901..6ac72354975 100644
--- a/packages/router-core/src/router.ts
+++ b/packages/router-core/src/router.ts
@@ -1766,7 +1766,7 @@ export class RouterCore<
       // This avoids creating full match objects (AbortController, ControlledPromise, etc.)
       // which are expensive and not needed for buildLocation
       const destMatchResult = this.getMatchedRoutes(interpolatedNextTo)
-      const destRoutes = destMatchResult.matchedRoutes
+      let destRoutes = destMatchResult.matchedRoutes
       const rawParams = destMatchResult.routeParams
 
       // Compute globalNotFoundRouteId using the same logic as matchRoutesInternal
@@ -1778,7 +1778,7 @@ export class RouterCore<
       let globalNotFoundRouteId: string | undefined
       if (isGlobalNotFound) {
         if (this.options.notFoundRoute) {
-          globalNotFoundRouteId = this.options.notFoundRoute.id
+          destRoutes = [...destRoutes, this.options.notFoundRoute]
         } else {
           globalNotFoundRouteId = findGlobalNotFoundRouteId(
             this.options.notFoundMode,