penguinui

web/src/ui/mod.rs

@@ -47,7 +47,8 @@ impl Default for Nav {
     }
 }
 
-/// The swap target every form POST answers with.
+/// The swap target every form POST answers with. An error carries the dialog
+/// that puts the message in front of the user; see `ui/alert_fragment.html`.
 #[derive(Template)]
 #[template(path = "ui/alert_fragment.html")]
 pub(crate) struct Alert<'a> {
@@ -117,3 +118,24 @@ pub(crate) fn render<T: Template>(template: &T) -> String {
         .render()
         .unwrap_or_else(|error| format!("<p class=\"error\">Template error: {error}</p>"))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Every form on the site answers through `Alert`, so this is the one
+    /// place that decides a failure cannot go unnoticed.
+    #[test]
+    fn a_failed_form_gets_a_dialog_and_a_successful_one_does_not() {
+        let failure = render(&Alert::error("Could not save", "A name is required."));
+        assert!(!failure.contains("Template error"), "{failure}");
+        assert!(failure.contains(r#"role="alert""#));
+        assert!(failure.contains(r#"role="dialog""#));
+        // Once in the inline alert, once in the dialog.
+        assert_eq!(failure.matches("A name is required.").count(), 2);
+
+        let success = render(&Alert::success("Saved", "Two rows written."));
+        assert!(success.contains(r#"role="alert""#));
+        assert!(!success.contains(r#"role="dialog""#));
+    }
+}