feat: integrate nstart (#33)

src/PageManager.tsx

@@ -105,10 +105,19 @@ export function PageManager({ maxStackSize = 5 }: { maxStackSize?: number }) {
     }
 
     const onPopState = (e: PopStateEvent) => {
-      const state = e.state ?? { index: -1, url: '/' }
+      let state = e.state as { index: number; url: string } | null
       setSecondaryStack((pre) => {
         const currentItem = pre[pre.length - 1] as TStackItem | undefined
         const currentIndex = currentItem?.index
+        if (!state) {
+          if (window.location.pathname + window.location.search + window.location.hash !== '/') {
+            // Just change the URL
+            return pre
+          } else {
+            // Back to root
+            state = { index: -1, url: '/' }
+          }
+        }
 
         // Go forward
         if (currentIndex === undefined || state.index > currentIndex) {
@@ -124,7 +133,7 @@ export function PageManager({ maxStackSize = 5 }: { maxStackSize?: number }) {
         }
 
         // Go back
-        const newStack = pre.filter((item) => item.index <= state.index)
+        const newStack = pre.filter((item) => item.index <= state!.index)
         const topItem = newStack[newStack.length - 1] as TStackItem | undefined
         if (!topItem) {
           // Create a new stack item if it's not exist (e.g. when the user refreshes the page, the stack will be empty)