feat(test): bind text assertions to targets

hemx-test/tests/inspector.rs

@@ -17,6 +17,40 @@ fn inspects_tuple_effects() {
     }));
 }
 
+#[test]
+fn text_update_condition_is_bound_to_the_expected_target() {
+    // req: test/018
+    let expected_target = TestTarget(ResourceKind::Slot, 42);
+    let inspected = hemx_test::inspect(vec![
+        Effect::Put {
+            target: ResourceRef::unscoped(ResourceId::new(ResourceKind::Slot, 42)),
+            payload: Payload::Text(String::from("wrong payload")),
+        },
+        Effect::Put {
+            target: ResourceRef::unscoped(ResourceId::new(ResourceKind::Slot, 7)),
+            payload: Payload::Text(String::from("expected fragment")),
+        },
+    ]);
+
+    assert!(inspected.updates_text(expected_target));
+    assert!(inspected.payload_contains("expected fragment"));
+    assert!(!inspected.updates_text_containing(expected_target, "expected fragment"));
+
+    let panic = std::panic::catch_unwind(|| {
+        inspected.assert_updates_text_containing(expected_target, "expected fragment");
+    })
+    .expect_err("a payload on another target must not satisfy the assertion");
+    let message = panic
+        .downcast_ref::<String>()
+        .map(String::as_str)
+        .or_else(|| panic.downcast_ref::<&str>().copied())
+        .expect("assertion panic must carry a message");
+
+    assert!(message.contains("expected fragment"), "{message}");
+    assert!(message.contains("wrong payload"), "{message}");
+    assert!(message.contains("ResourceId"), "{message}");
+}
+
 #[test]
 fn html_update_assertion_reports_expectation_and_actual_effects() {
     // req: test/018