Add failing test for #589

test/apps/with-basepath/src/routes/index.svelte

@@ -1 +1,2 @@
-<h1>Great success!</h1>
+<h1>Great success!</h1>
+<a href="redirect-from">redirect from</a>

test/apps/with-basepath/src/routes/redirect-from.svelte

@@ -0,0 +1,7 @@
+<script context="module">
+  export function preload() {
+    this.redirect(301, 'redirect-to');
+  }
+</script>
+
+<h1>unredirected</h1>

test/apps/with-basepath/src/routes/redirect-to.svelte

@@ -0,0 +1 @@
+<h1>redirected</h1>