feat: preserve query string when redirecting on first visit (web-infr…

…a-dev#864)

Co-authored-by: neverland <[email protected]>

.changeset/cyan-tigers-bow.md

@@ -0,0 +1,5 @@
+---
+"@rspress/theme-default": minor
+---
+
+feat: preserve query string when redirecting on first visit

packages/theme-default/src/logic/useRedirect4FirstVisit.ts

@@ -22,7 +22,7 @@ export function useRedirect4FirstVisit() {
       return;
     }
     // Normalize current url, to ensure that the home url is always with a trailing slash
-    const { pathname } = window.location;
+    const { pathname, search } = window.location;
     const cleanPathname = removeBase(pathname);
     // Check if the user is visiting the site for the first time
     const FIRST_VISIT_KEY = 'rspress-visited';
@@ -37,19 +37,22 @@ export function useRedirect4FirstVisit() {
     if (!langs.includes(targetLang)) {
       return;
     }
-    if (targetLang !== currentLang) {
-      if (targetLang === defaultLang) {
-        // Redirect to the default language
-        window.location.replace(pathname.replace(`/${currentLang}`, ''));
-      } else if (currentLang === defaultLang) {
-        // Redirect to the current language
-        window.location.replace(withBase(`/${targetLang}${cleanPathname}`));
-      } else {
-        // Redirect to the current language
-        window.location.replace(
-          pathname.replace(`/${currentLang}`, `/${targetLang}`),
-        );
-      }
+    if (targetLang === currentLang) {
+      return;
+    }
+    let newPath: string;
+    if (targetLang === defaultLang) {
+      // Redirect to the default language
+      newPath = pathname.replace(`/${currentLang}`, '');
+    } else if (currentLang === defaultLang) {
+      // Redirect to the current language
+      newPath = withBase(`/${targetLang}${cleanPathname}`);
+    } else {
+      // Redirect to the current language
+      newPath = pathname.replace(`/${currentLang}`, `/${targetLang}`);
+    }
+    if (newPath) {
+      window.location.replace(newPath + search);
     }
   }, []);
 }