Fix

Author: brophdawg11

.changeset/real-rules-compare.md

@@ -0,0 +1,5 @@
+---
+"react-router": patch
+---
+
+Fix `TypeError` if you throw from `patchRoutesOnNavigation` when no partial matches exist

packages/react-router/__tests__/router/lazy-discovery-test.ts

@@ -2115,15 +2115,6 @@ describe("Lazy Route Discovery (Fog of War)", () => {
         async patchRoutesOnNavigation({ patch }) {
           await tick();
           throw new Error("broke!");
-          patch("b", [
-            {
-              id: "b",
-              path: "b",
-              loader() {
-                return "B";
-              },
-            },
-          ]);
         },
       });
 
@@ -2151,15 +2142,6 @@ describe("Lazy Route Discovery (Fog of War)", () => {
         async patchRoutesOnNavigation({ patch }) {
           await tick();
           throw new Error("broke!");
-          patch("b", [
-            {
-              id: "b",
-              path: "b",
-              action() {
-                return "B";
-              },
-            },
-          ]);
         },
       });
 

packages/react-router/lib/router/router.ts

@@ -1802,8 +1802,9 @@ export function createRouter(init: RouterInit): Router {
       if (discoverResult.type === "aborted") {
         return { shortCircuited: true };
       } else if (discoverResult.type === "error") {
-        let boundaryId = findNearestBoundary(discoverResult.partialMatches)
-          .route.id;
+        let boundaryId =
+          findNearestBoundary(discoverResult.partialMatches)?.route.id ??
+          getShortCircuitMatches(dataRoutes).route.id;
         return {
           matches: discoverResult.partialMatches,
           pendingActionResult: [
@@ -1996,8 +1997,9 @@ export function createRouter(init: RouterInit): Router {
       if (discoverResult.type === "aborted") {
         return { shortCircuited: true };
       } else if (discoverResult.type === "error") {
-        let boundaryId = findNearestBoundary(discoverResult.partialMatches)
-          .route.id;
+        let boundaryId =
+          findNearestBoundary(discoverResult.partialMatches)?.route.id ??
+          getShortCircuitMatches(dataRoutes).route.id;
         return {
           matches: discoverResult.partialMatches,
           loaderData: {},