fix: ensure pages routes are defined correctly

In e151223 we introduced a bug where the RouteKey was now an array rather than a simple URL string. When it got stringified into the routing object these were invalid.
E.g. `[':page*', undefined]` got stringified to `":page*,"` rather than `":page*"`.

Fixes #379

.changeset/chilled-ties-lay.md

@@ -0,0 +1,10 @@
+---
+"wrangler": patch
+---
+
+fix: ensure pages routes are defined correctly
+
+In e151223 we introduced a bug where the RouteKey was now an array rather than a simple URL string. When it got stringified into the routing object these were invalid.
+E.g. `[':page*', undefined]` got stringified to `":page*,"` rather than `":page*"`.
+
+Fixes #379

packages/wrangler/pages/functions/filepath-routing.ts

@@ -155,7 +155,14 @@ export async function generateConfigFromFileTree({
 
   routeEntries.sort(([a], [b]) => compareRoutes(a, b));
 
-  return { routes: Object.fromEntries(routeEntries) } as Config;
+  return {
+    routes: Object.fromEntries(
+      routeEntries.map(([routeKey, routeConfig]) => [
+        stringifyRouteKey(routeKey),
+        routeConfig,
+      ])
+    ),
+  } as Config;
 }
 
 // Ensure routes are produced in order of precedence so that
@@ -229,3 +236,7 @@ interface NonEmptyArray<T> extends Array<T> {
 function isNotEmpty<T>(array: T[]): array is NonEmptyArray<T> {
   return array.length > 0;
 }
+
+function stringifyRouteKey(routeKey: RouteKey): string {
+  return (routeKey[1] ? `${routeKey[1]} ` : "") + routeKey[0];
+}