fix(vue): guard traceVueRouter cleanup + pin router-tracing edge cases

Guard the WeakMap delete in cleanup() so a stale HMR cleanup can't
disable dedup for the active guards. Add coverage for the onError
empty-name fallback and blocked-initial-navigation pageload naming,
and assert the settled route name (not just call count) on the
existing onError test.

Author: DriesH

packages/vue/src/traceVueRouter.ts

@@ -127,7 +127,7 @@ export function traceVueRouter(router: unknown): () => void {
         safeInvoke(offAfter);
         safeInvoke(offError);
         safeInvoke(() => nav.unregister());
-        instrumented.delete(r);
+        if (instrumented.get(r) === cleanup) instrumented.delete(r);
     };
     instrumented.set(r, cleanup);
     return cleanup;

packages/vue/tests/vue-router.integration.test.ts

@@ -178,6 +178,7 @@ describe('traceVueRouter against a real vue-router', () => {
         await router.push('/product/p01').catch(() => {});
         expect(nav.startNavigation).toHaveBeenCalledTimes(1);
         expect(nav.settleNavigation).toHaveBeenCalledTimes(1);
+        expect(nav.settleNavigation).toHaveBeenLastCalledWith({ name: '/', source: 'route' });
     });
 
     it('names the pageload immediately when installed after the router is ready', async () => {

packages/vue/tests/vue-router.test.ts

@@ -33,7 +33,7 @@ import { traceVueRouter } from '../src/traceVueRouter';
 type Loc = { path: string; fullPath: string; matched: { path: string }[] };
 type Guard = (...a: any[]) => unknown;
 
-function fakeRouter(current: Loc) {
+function fakeRouter(current: Loc | undefined) {
     let before: Guard[] = [];
     let after: Guard[] = [];
     let error: Guard[] = [];
@@ -59,13 +59,16 @@ function fakeRouter(current: Loc) {
         },
         fireBefore: (to: Loc, from: Loc) => before.forEach((g) => g(to, from)),
         fireAfter: (to: Loc, from: Loc, failure?: { type: number }) => after.forEach((g) => g(to, from, failure)),
+        fireError: () => error.forEach((g) => g()),
         counts: () => ({ before: before.length, after: after.length, error: error.length }),
     };
 }
 
 const home: Loc = { path: '/', fullPath: '/', matched: [{ path: '/' }] };
 const product: Loc = { path: '/product/p01', fullPath: '/product/p01', matched: [{ path: '/product/:id' }] };
 const cart: Loc = { path: '/cart', fullPath: '/cart', matched: [{ path: '/cart' }] };
+const blocked: Loc = { path: '/blocked', fullPath: '/blocked', matched: [{ path: '/blocked' }] };
+const START: Loc = { path: '/', fullPath: '/', matched: [] };
 
 beforeEach(() => {
     nav.startNavigation.mockClear();
@@ -102,4 +105,23 @@ describe('traceVueRouter edge cases', () => {
         expect(router.counts()).toEqual({ before: 1, after: 1, error: 1 }); // prior removed, not doubled
         expect(nav.unregister).toHaveBeenCalledTimes(1); // prior nav source released
     });
+
+    it('falls back to an empty name on onError when there is no current route', () => {
+        const router = fakeRouter(undefined); // currentRoute.value is undefined
+        traceVueRouter(router); // must not throw on install-time enrichment either
+        router.fireBefore(product, home); // client nav (home has matched → not initial): opens held root
+        router.fireError();
+        expect(nav.settleNavigation).toHaveBeenLastCalledWith({ name: '', source: 'url' });
+    });
+
+    it('keeps a blocked initial navigation in pageload naming until the first success', () => {
+        const router = fakeRouter(START); // START_LOCATION-like: empty matched → sawInitial stays false
+        traceVueRouter(router);
+        router.fireBefore(blocked, START); // treated as pageload naming, no nav root
+        router.fireAfter(blocked, START, { type: 4 }); // aborted initial → still no nav root, sawInitial stays false
+        router.fireBefore(product, START); // from is still START: aborted nav never committed
+        router.fireAfter(product, START, undefined); // success → finalizes the pageload name
+        expect(nav.startNavigation).not.toHaveBeenCalled();
+        expect(nav.setActiveRouteName).toHaveBeenLastCalledWith({ name: '/product/:id', source: 'route' });
+    });
 });