fix: SPA routing is broken unless origin matches value in in vite.config #8093

.changeset/spicy-seas-check.md

@@ -0,0 +1,14 @@
+---
+'@builder.io/qwik-city': patch
+---
+
+fix: SPA routing is broken unless origin matches value in in vite.config #8093
+
+If the SSG origin was set to `localhost:3000` and a user visited from `127.0.0.1:3000`, SPA routing would be broken.
+
+Internally, useNavigate's context provider `goto` checks the new destination with the last route location. If the
+origin is different, it just does a normal browser navigation. This makes sense; links to other origins cannot use
+SPA routing. However, the initial route it compares was using an origin that came from the server environment.
+
+Now, the first navigation will set that initial route to the browser's actual href, eliminating the erroneous
+origin mismatch for SPA navigations.

packages/qwik-city/src/runtime/src/qwik-city-component.tsx

@@ -139,13 +139,19 @@ export const QwikCityProvider = component$<QwikCityProps>((props) => {
   );
   const navResolver: { r?: () => void } = {};
   const loaderState = _weakSerialize(useStore(env.response.loaders, { deep: false }));
+
+  // The initial state of routeInternal uses the URL provided by the server environment.
+  // It may not be accurate to the actual URL the browser is accessing the site from.
+  // It is useful for the purposes of SSR and SSG, but may be overridden browser-side
+  // if needed for SPA routing.
   const routeInternal = useSignal<RouteStateInternal>({
     type: 'initial',
     dest: url,
     forceReload: false,
     replaceState: false,
     scroll: true,
   });
+
   const documentHead = useStore<Editable<ResolvedDocumentHead>>(createDocumentHead);
   const content = useStore<Editable<ContentState>>({
     headings: undefined,
@@ -218,6 +224,15 @@ export const QwikCityProvider = component$<QwikCityProps>((props) => {
     } = typeof opt === 'object' ? opt : { forceReload: opt };
     internalState.navCount++;
 
+    // If this is the first SPA navigation, we rewrite routeInternal's URL
+    // as the browser location URL to prevent an erroneous origin mismatch.
+    // The initial value of routeInternal is derived from the server env,
+    // which in the case of SSG may not match the actual origin the site
+    // is deployed on.
+    if (isBrowser && routeInternal.value.type === 'initial') {
+      routeInternal.value.dest = new URL(window.location.href);
+    }
+
     const lastDest = routeInternal.value.dest;
     const dest =
       path === undefined