update missed Rust test

Author: janechu

crates/microsoft-fast-build/tests/custom_elements.rs

@@ -634,7 +634,7 @@ fn test_root_custom_element_missing_binding_attr_omitted() {
         None,
     ).unwrap();
     assert!(!result.contains("text="), "missing binding attr omitted: {result}");
-    assert!(result.contains("<!--fe-b$$start$$0$$text-0$$fe-b--><!--fe-b$$end$$0$$text-0$$fe-b-->"));
+    assert!(result.contains("<!--fe:b--><!--fe:/b-->"), "content binding marker: {result}");
 }
 
 #[test]

crates/microsoft-fast-build/tests/edge_cases.rs

@@ -115,7 +115,7 @@ fn test_render_entry_with_locator_without_state_uses_empty_object() {
     let result = render_entry_with_locator_without_state("<my-el></my-el>", &locator, None)
         .expect("render entry without state");
     assert!(result.contains("<span>"), "shadow content rendered: {result}");
-    assert!(result.contains("<!--fe-b$$start$$0$$label-0$$fe-b--><!--fe-b$$end$$0$$label-0$$fe-b-->"));
+    assert!(result.contains("<!--fe:b--><!--fe:/b-->"), "content binding marker: {result}");
 }
 
 // ── deeply nested property access ─────────────────────────────────────────────

crates/microsoft-fast-build/tests/hydration.rs

@@ -98,7 +98,7 @@ fn test_hydration_missing_attribute_binding_omits_attribute() {
     ).unwrap();
 
     let shadow = extract_shadow(&result);
-    assert!(shadow.contains("data-fe-c-0-2"), "compact marker: {result}");
+    assert!(shadow.contains(r#"data-fe="2""#), "compact marker: {result}");
     assert!(shadow.contains(r#"type="text""#), "resolved attr: {result}");
     assert!(shadow.contains(r#"class="static""#), "static attr: {result}");
     assert!(!shadow.contains("value="), "missing attr omitted: {result}");
@@ -616,9 +616,9 @@ fn test_hydration_nested_element_missing_attr_binding_omits_attribute() {
         None,
     ).unwrap();
 
-    assert!(result.contains("data-fe-c-0-1"), "attr binding marker remains: {result}");
+    assert!(result.contains(r#"data-fe="1""#), "attr binding marker remains: {result}");
     assert!(!result.contains("label="), "missing attr omitted: {result}");
-    assert!(result.contains("<!--fe-b$$start$$0$$label-0$$fe-b--><!--fe-b$$end$$0$$label-0$$fe-b-->"));
+    assert!(result.contains("<!--fe:b--><!--fe:/b-->"), "content binding marker: {result}");
 }
 
 // ── Unescaped triple-brace ────────────────────────────────────────────────────