Fix Trusted Types navigation and fragment history loops

packages/csr/test/nav.test.ts

@@ -7,7 +7,7 @@ let win: any;
 let fetchCalls: { url: string; opts: any }[];
 let nextHtml: string;
 
-function install(bodyHtml: string): void {
+function install(bodyHtml: string, configure?: (window: any) => void): void {
   win = new Window({ url: "https://example.test/" });
   win.document.body.innerHTML = bodyHtml;
   fetchCalls = [];
@@ -32,6 +32,7 @@ function install(bodyHtml: string): void {
       text: () => Promise.resolve(nextHtml),
     });
   };
+  configure?.(win);
   (0, eval)(NAV_RUNTIME);
 }
 
@@ -71,6 +72,38 @@ test("intercepts an internal link click and swaps #app in place", async () => {
   expect(win.document.title).toBe("About");
 });
 
+test("fragment history navigation preserves the page without fetching", async () => {
+  install('<div id="app"><input value="Unsaved draft"></div>');
+  win.history.pushState({}, "", "/#setup-commands");
+  win.dispatchEvent(new win.PopStateEvent("popstate"));
+  await flush();
+  expect(fetchCalls).toHaveLength(0);
+  expect(win.document.querySelector("input").value).toBe("Unsaved draft");
+});
+
+test("navigation supplies TrustedHTML to the document parser", async () => {
+  let parses = 0;
+  install('<div id="app"><a href="/next" id="lnk">Next</a></div>', (window) => {
+    window.trustedTypes = { createPolicy: (_name: string, rules: any) => ({
+      createHTML: (value: string) => ({ trusted: true, value: rules.createHTML(value) }),
+      createScriptURL: rules.createScriptURL,
+    }) };
+    const Parser = window.DOMParser;
+    (globalThis as any).DOMParser = class {
+      parseFromString(value: any, type: string) {
+        if (!value?.trusted) throw new TypeError("TrustedHTML required");
+        parses++;
+        return new Parser().parseFromString(value.value, type);
+      }
+    };
+  });
+  nextHtml = '<html><body><div id="app">Next page</div></body></html>';
+  win.document.getElementById("lnk").click();
+  await flush();
+  expect(parses).toBe(1);
+  expect(win.document.getElementById("app").textContent).toBe("Next page");
+});
+
 test("navigation replaces document control registries before hydration", async () => {
   install('<div id="app"><a href="/next" id="lnk">Next</a></div><script type="application/json" data-wrn-controls id="old">[]</script>');
   nextHtml = '<html><body><div id="app">Next</div><script type="application/json" data-wrn-controls id="new">[[{"cond":null,"body":"Ready"}]]</script></body></html>';