feat(hemx): clarify generated authoring path

Close the fallible handler and example coherence slice: v0 uses typed todo newtypes, Result handler failure mapping, generated form/partial helpers, and page composition; kanban is explicitly marked as an advanced north-star milestone; raw render is isolated behind hemx::advanced::render.

req: canonical_authoring/003

req: failure/004

req: public_api/005

req: examples/004

hemx-axum/tests/response.rs

@@ -1,14 +1,14 @@
 use axum::extract::State;
 use axum::http::{header, HeaderMap};
 use axum::response::IntoResponse;
-use scraper::{Html, Selector};
 use hemx_axum::{
-    interactions, runtime_js, DispatchRejection, EffectResponse, Form, InteractionForm,
-    InteractionFormRejection, InteractionRequest, PageMode, PageRequest, PageResponse,
-    HEMX_CONTENT_TYPE, HEMX_FINGERPRINT_HEADER, HEMX_PARTIAL_HEADER, HEMX_RUNTIME_CONTENT_TYPE,
-    HEMX_TITLE_HEADER,
+    interactions, runtime_js, DispatchRejection, EffectResponse, Form, HandlerErrorContext,
+    HandlerFailure, InteractionForm, InteractionFormRejection, InteractionRequest,
+    IntoHandlerFailure, PageMode, PageRequest, PageResponse, HEMX_CONTENT_TYPE,
+    HEMX_FINGERPRINT_HEADER, HEMX_PARTIAL_HEADER, HEMX_RUNTIME_CONTENT_TYPE, HEMX_TITLE_HEADER,
 };
 use hemx_core::{push, BuildFingerprint, Handle, IntoEffect, SafeHtml, Slot};
+use scraper::{Html, Selector};
 
 fn selector(value: &str) -> Selector {
     Selector::parse(value).expect("test selector parses")
@@ -306,6 +306,21 @@ impl std::fmt::Display for HandlerBoom {
 
 impl std::error::Error for HandlerBoom {}
 
+impl IntoHandlerFailure for HandlerBoom {
+    fn into_handler_failure(self, _context: HandlerErrorContext) -> HandlerFailure {
+        HandlerFailure::internal(self.to_string())
+    }
+}
+
+#[derive(Debug)]
+struct UiFailure;
+
+impl IntoHandlerFailure for UiFailure {
+    fn into_handler_failure(self, context: HandlerErrorContext) -> HandlerFailure {
+        HandlerFailure::effects(Slot::<String>::new(3).text("try again"), context)
+    }
+}
+
 #[tokio::test]
 async fn interaction_request_dispatches_async_typed_state_extractors() {
     // req: axum_integration/003 req: form/004 req: canonical_authoring/003
@@ -359,10 +374,69 @@ async fn interaction_request_reports_async_result_handler_errors() {
 
     assert_eq!(
         error,
-        DispatchRejection::HandlerError {
-            handle_id: 11,
+        DispatchRejection::HandlerError(HandlerFailure::Response {
+            status: axum::http::StatusCode::INTERNAL_SERVER_ERROR,
             message: "database unavailable".to_owned(),
-        }
+        })
+    );
+}
+
+#[tokio::test]
+async fn interaction_request_maps_async_result_errors_to_effects() {
+    // req: axum_integration/003 req: failure/004
+    async fn open_project(
+        State(_multiplier): State<u32>,
+        Form(_input): Form<OpenProject>,
+    ) -> Result<impl IntoEffect, UiFailure> {
+        Err::<(), _>(UiFailure)
+    }
+
+    let request = InteractionRequest::from(InteractionForm::for_handle(
+        Handle::<()>::new(12),
+        vec![("project_id".to_owned(), "21".to_owned())],
+    ));
+    let response = request
+        .dispatch_async(
+            interactions(BuildFingerprint(4))
+                .with_state(2_u32)
+                .on_async_result(Handle::<()>::new(12), open_project)
+                .into_registry(),
+        )
+        .await
+        .unwrap();
+
+    assert_eq!(
+        response.batch.ops,
+        vec![Slot::<String>::new(3).text("try again")]
+    );
+}
+
+#[test]
+fn interaction_request_maps_sync_result_errors_to_effects() {
+    // req: axum_integration/003 req: failure/004
+    fn open_project(
+        State(_multiplier): State<u32>,
+        Form(_input): Form<OpenProject>,
+    ) -> Result<impl IntoEffect, UiFailure> {
+        Err::<(), _>(UiFailure)
+    }
+
+    let request = InteractionRequest::from(InteractionForm::for_handle(
+        Handle::<()>::new(13),
+        vec![("project_id".to_owned(), "21".to_owned())],
+    ));
+    let response = request
+        .dispatch(
+            interactions(BuildFingerprint(4))
+                .with_state(2_u32)
+                .on_result(Handle::<()>::new(13), open_project)
+                .into_registry(),
+        )
+        .unwrap();
+
+    assert_eq!(
+        response.batch.ops,
+        vec![Slot::<String>::new(3).text("try again")]
     );
 }