Fix hydration error suspense (#4640)

* Fix hydration of error boundaries

* add a regression test

* add more comments

* fix typos

* more typos

* fix clippy

packages/fullstack-hooks/src/errors.rs

@@ -0,0 +1,29 @@
+//! Contains a hydration compatible error boundary context.
+
+use dioxus_core::{spawn_isomorphic, CapturedError, ErrorContext, ReactiveContext};
+use dioxus_fullstack_protocol::serialize_context;
+use futures_util::StreamExt;
+
+/// Initializes an error boundary context that is compatible with hydration.
+pub fn init_error_boundary() -> ErrorContext {
+    let initial_errors = serialize_context().create_entry::<Vec<CapturedError>>();
+    let (rx_context, mut rx) = ReactiveContext::new();
+    let errors = ErrorContext::new(Vec::new());
+    for error in initial_errors.get().iter().flatten() {
+        errors.insert_error(error.clone());
+    }
+    rx_context.run_in(|| {
+        errors.errors();
+    });
+    spawn_isomorphic({
+        let errors = errors.clone();
+        async move {
+            if rx.next().await.is_some() {
+                rx_context.run_in(|| {
+                    initial_errors.insert(&errors.errors().to_vec(), std::panic::Location::caller())
+                });
+            }
+        }
+    });
+    errors
+}

packages/fullstack-hooks/src/lib.rs

@@ -2,6 +2,7 @@
 #![doc = include_str!("../README.md")]
 
 pub mod document;
+pub mod errors;
 pub mod history;
 mod hooks;
 mod streaming;