fix: schedule ActionForm submit handler to run after user submit handlers (closes #3872)

A place to put e2e tests for regression, plus reporting issue caused by #4091.

examples/regression/Cargo.toml

@@ -0,0 +1,90 @@
+[package]
+name = "regression"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+axum = { version = "0.8.1", optional = true }
+console_error_panic_hook = "0.1.7"
+console_log = "1.0"
+leptos = { path = "../../leptos", features = ["tracing"] }
+leptos_meta = { path = "../../meta" }
+leptos_axum = { path = "../../integrations/axum", optional = true }
+leptos_router = { path = "../../router" }
+serde = { version = "1.0", features = ["derive"] }
+thiserror = "1.0"
+tokio = { version = "1.39", features = [ "rt-multi-thread", "macros", "time" ], optional = true }
+wasm-bindgen = "0.2.92"
+
+[features]
+hydrate = [
+  "leptos/hydrate",
+]
+ssr = [
+  "dep:axum",
+  "dep:tokio",
+  "leptos/ssr",
+  "leptos_meta/ssr",
+  "dep:leptos_axum",
+  "leptos_router/ssr",
+]
+
+[profile.release]
+panic = "abort"
+
+[profile.wasm-release]
+inherits = "release"
+opt-level = 'z'
+lto = true
+codegen-units = 1
+panic = "abort"
+
+[package.metadata.cargo-all-features]
+denylist = ["axum", "tower", "tower-http", "tokio", "sqlx", "leptos_axum"]
+skip_feature_sets = [["ssr", "hydrate"]]
+
+[package.metadata.leptos]
+# The name used by wasm-bindgen/cargo-leptos for the JS/WASM bundle. Defaults to the crate name
+output-name = "regression"
+# The site root folder is where cargo-leptos generate all output. WARNING: all content of this folder will be erased on a rebuild. Use it in your server setup.
+site-root = "target/site"
+# The site-root relative folder where all compiled output (JS, WASM and CSS) is written
+# Defaults to pkg
+site-pkg-dir = "pkg"
+# The IP and port (ex: 127.0.0.1:3000) where the server serves the content. Use it in your server setup.
+site-addr = "127.0.0.1:3000"
+# The port to use for automatic reload monitoring
+reload-port = 3001
+# [Optional] Command to use when running end2end tests. It will run in the end2end dir.
+#   [Windows] for non-WSL use "npx.cmd playwright test"
+#   This binary name can be checked in Powershell with Get-Command npx
+end2end-cmd = "cargo make test-ui"
+end2end-dir = "e2e"
+#  The browserlist query used for optimizing the CSS.
+browserquery = "defaults"
+# Set by cargo-leptos watch when building with that tool. Controls whether autoreload JS will be included in the head
+watch = false
+# The environment Leptos will run in, usually either "DEV" or "PROD"
+env = "DEV"
+# The features to use when compiling the bin target
+#
+# Optional. Can be over-ridden with the command line parameter --bin-features
+bin-features = ["ssr"]
+
+# If the --no-default-features flag should be used when compiling the bin target
+#
+# Optional. Defaults to false.
+bin-default-features = false
+
+# The features to use when compiling the lib target
+#
+# Optional. Can be over-ridden with the command line parameter --lib-features
+lib-features = ["hydrate"]
+
+# If the --no-default-features flag should be used when compiling the lib target
+#
+# Optional. Defaults to false.
+lib-default-features = false

examples/regression/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 Leptos
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

examples/regression/Makefile.toml

@@ -0,0 +1,8 @@
+extend = [
+    { path = "../cargo-make/main.toml" },
+    { path = "../cargo-make/cargo-leptos-webdriver-test.toml" },
+]
+
+[env]
+
+CLIENT_PROCESS_NAME = "regression"

examples/regression/README.md

@@ -0,0 +1,8 @@
+# Regression Tests
+
+This example functions as a catch-all for all current and future regression
+test cases that typically happens at integration.
+
+## Quick Start
+
+Run `cargo leptos watch` to run this example.

examples/regression/e2e/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "regression_e2e"
+version = "0.1.0"
+edition = "2021"
+
+[dev-dependencies]
+anyhow = "1.0"
+async-trait = "0.1.81"
+cucumber = "0.21.1"
+fantoccini = "0.21.1"
+pretty_assertions = "1.4"
+serde_json = "1.0"
+tokio = { version = "1.39", features = ["macros", "rt-multi-thread", "time"] }
+url = "2.5"
+
+[[test]]
+name = "app_suite"
+harness = false    # Allow Cucumber to print output instead of libtest

examples/regression/e2e/Makefile.toml

@@ -0,0 +1,20 @@
+extend = { path = "../../cargo-make/main.toml" }
+
+[tasks.test]
+env = { RUN_AUTOMATICALLY = false }
+condition = { env_true = ["RUN_AUTOMATICALLY"] }
+
+[tasks.ci]
+
+[tasks.test-ui]
+command = "cargo"
+args = [
+  "test",
+  "--test",
+  "app_suite",
+  "--",
+  "--retry",
+  "2",
+  "--fail-fast",
+  "${@}",
+]

examples/regression/e2e/README.md

@@ -0,0 +1,34 @@
+# E2E Testing
+
+This example demonstrates e2e testing with Rust using executable requirements.
+
+## Testing Stack
+
+|    |      Role      |  Description |
+|---|---|---|
+| [Cucumber](https://github.com/cucumber-rs/cucumber/tree/main) | Test Runner | Run [Gherkin](https://cucumber.io/docs/gherkin/reference/) specifications as Rust tests |
+| [Fantoccini](https://github.com/jonhoo/fantoccini/tree/main) | Browser Client | Interact with web pages through WebDriver |
+| [Cargo Leptos](https://github.com/leptos-rs/cargo-leptos) | Build Tool |  Compile example and start the server and end-2-end tests |
+| [chromedriver](https://chromedriver.chromium.org/downloads) | WebDriver | Provide WebDriver for Chrome |
+
+## Testing Organization
+
+Testing is organized around what a user can do and see/not see. Test scenarios are grouped by the **user action** and the **object** of that action. This makes it easier to locate and reason about requirements.
+
+Here is a brief overview of how things fit together.
+
+```bash
+features
+└── {action}_{object}.feature   # Specify test scenarios
+tests
+├── fixtures
+│   ├── action.rs               # Perform a user action (click, type, etc.)
+│   ├── check.rs                # Assert what a user can see/not see
+│   ├── find.rs                 # Query page elements
+│   ├── mod.rs
+│   └── world
+│       ├── action_steps.rs     # Map Gherkin steps to user actions
+│       ├── check_steps.rs      # Map Gherkin steps to user expectations
+│       └── mod.rs
+└── app_suite.rs                # Test main
+```

examples/regression/e2e/features/pr_4091.feature

@@ -0,0 +1,26 @@
+@check_pr_4091
+Feature: Regression from pull request 4091
+
+    Scenario: Signal for testing should work
+        Given I see the app
+        And I can access regression test 4091
+        When I select the link test1
+        Then I see the result is the string Test1
+
+    Scenario: The result returns to empty due to on_cleanup
+        Given I see the app
+        And I can access regression test 4091
+        When I select the following links
+            | test1     |
+            | 4091 Home |
+        Then I see the result is empty
+
+    Scenario: The result does not accumulate due to on_cleanup
+        Given I see the app
+        And I can access regression test 4091
+        When I select the following links
+            | test1     |
+            | 4091 Home |
+            | test1     |
+            | 4091 Home |
+        Then I see the result is empty

examples/regression/e2e/tests/app_suite.rs

@@ -0,0 +1,30 @@
+mod fixtures;
+
+use anyhow::Result;
+use cucumber::World;
+use fixtures::world::AppWorld;
+use std::{ffi::OsStr, fs::read_dir};
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    // Normally the below is done, but it's now gotten to the point of
+    // having a sufficient number of tests where the resource contention
+    // of the concurrently running browsers will cause failures on CI.
+    // AppWorld::cucumber()
+    //     .fail_on_skipped()
+    //     .run_and_exit("./features")
+    //     .await;
+
+    // Mitigate the issue by manually stepping through each feature,
+    // rather than letting cucumber glob them and dispatch all at once.
+    for entry in read_dir("./features")? {
+        let path = entry?.path();
+        if path.extension() == Some(OsStr::new("feature")) {
+            AppWorld::cucumber()
+                .fail_on_skipped()
+                .run_and_exit(path)
+                .await;
+        }
+    }
+    Ok(())
+}

examples/regression/e2e/tests/fixtures/action.rs

@@ -0,0 +1,17 @@
+use super::{find, world::HOST};
+use anyhow::Result;
+use fantoccini::Client;
+use std::result::Result::Ok;
+
+pub async fn goto_path(client: &Client, path: &str) -> Result<()> {
+    let url = format!("{}{}", HOST, path);
+    client.goto(&url).await?;
+
+    Ok(())
+}
+
+pub async fn click_link(client: &Client, text: &str) -> Result<()> {
+    let link = find::link_with_text(&client, &text).await?;
+    link.click().await?;
+    Ok(())
+}

examples/regression/e2e/tests/fixtures/check.rs

@@ -0,0 +1,13 @@
+use crate::fixtures::find;
+use anyhow::{Ok, Result};
+use fantoccini::Client;
+use pretty_assertions::assert_eq;
+
+pub async fn result_text_is(
+    client: &Client,
+    expected_text: &str,
+) -> Result<()> {
+    let actual = find::text_at_id(client, "result").await?;
+    assert_eq!(&actual, expected_text);
+    Ok(())
+}

examples/regression/e2e/tests/fixtures/find.rs

@@ -0,0 +1,21 @@
+use anyhow::{Ok, Result};
+use fantoccini::{elements::Element, Client, Locator};
+
+pub async fn text_at_id(client: &Client, id: &str) -> Result<String> {
+    let element = client
+        .wait()
+        .for_element(Locator::Id(id))
+        .await
+        .expect(format!("no such element with id `{}`", id).as_str());
+    let text = element.text().await?;
+    Ok(text)
+}
+
+pub async fn link_with_text(client: &Client, text: &str) -> Result<Element> {
+    let link = client
+        .wait()
+        .for_element(Locator::LinkText(text))
+        .await
+        .expect(format!("Link not found by `{}`", text).as_str());
+    Ok(link)
+}

examples/regression/e2e/tests/fixtures/mod.rs

@@ -0,0 +1,4 @@
+pub mod action;
+pub mod check;
+pub mod find;
+pub mod world;

examples/regression/e2e/tests/fixtures/world/action_steps.rs

@@ -0,0 +1,47 @@
+use crate::fixtures::{action, world::AppWorld};
+use anyhow::{Ok, Result};
+use cucumber::{gherkin::Step, given, when};
+
+#[given("I see the app")]
+#[when("I open the app")]
+async fn i_open_the_app(world: &mut AppWorld) -> Result<()> {
+    let client = &world.client;
+    action::goto_path(client, "").await?;
+
+    Ok(())
+}
+
+#[given(regex = "^I can access regression test (.*)$")]
+#[when(regex = "^I select the link (.*)$")]
+async fn i_select_the_link(world: &mut AppWorld, text: String) -> Result<()> {
+    let client = &world.client;
+    action::click_link(client, &text).await?;
+
+    Ok(())
+}
+
+#[given(expr = "I select the following links")]
+#[when(expr = "I select the following links")]
+async fn i_select_the_following_links(
+    world: &mut AppWorld,
+    step: &Step,
+) -> Result<()> {
+    let client = &world.client;
+
+    if let Some(table) = step.table.as_ref() {
+        for row in table.rows.iter() {
+            action::click_link(client, &row[0]).await?;
+        }
+    }
+
+    Ok(())
+}
+
+#[given(regex = "^I (refresh|reload) the (browser|page)$")]
+#[when(regex = "^I (refresh|reload) the (browser|page)$")]
+async fn i_refresh_the_browser(world: &mut AppWorld) -> Result<()> {
+    let client = &world.client;
+    client.refresh().await?;
+
+    Ok(())
+}

examples/regression/e2e/tests/fixtures/world/check_steps.rs

@@ -0,0 +1,22 @@
+use crate::fixtures::{check, world::AppWorld};
+use anyhow::{Ok, Result};
+use cucumber::then;
+
+#[then(regex = r"^I see the result is empty$")]
+async fn i_see_the_result_is_empty(
+    world: &mut AppWorld,
+) -> Result<()> {
+    let client = &world.client;
+    check::result_text_is(client, "").await?;
+    Ok(())
+}
+
+#[then(regex = r"^I see the result is the string (.*)$")]
+async fn i_see_the_result_is_the_string(
+    world: &mut AppWorld,
+    text: String,
+) -> Result<()> {
+    let client = &world.client;
+    check::result_text_is(client, &text).await?;
+    Ok(())
+}

examples/regression/e2e/tests/fixtures/world/mod.rs

@@ -0,0 +1,39 @@
+pub mod action_steps;
+pub mod check_steps;
+
+use anyhow::Result;
+use cucumber::World;
+use fantoccini::{
+    error::NewSessionError, wd::Capabilities, Client, ClientBuilder,
+};
+
+pub const HOST: &str = "http://127.0.0.1:3000";
+
+#[derive(Debug, World)]
+#[world(init = Self::new)]
+pub struct AppWorld {
+    pub client: Client,
+}
+
+impl AppWorld {
+    async fn new() -> Result<Self, anyhow::Error> {
+        let webdriver_client = build_client().await?;
+
+        Ok(Self {
+            client: webdriver_client,
+        })
+    }
+}
+
+async fn build_client() -> Result<Client, NewSessionError> {
+    let mut cap = Capabilities::new();
+    let arg = serde_json::from_str("{\"args\": [\"-headless\"]}").unwrap();
+    cap.insert("goog:chromeOptions".to_string(), arg);
+
+    let client = ClientBuilder::native()
+        .capabilities(cap)
+        .connect("http://localhost:4444")
+        .await?;
+
+    Ok(client)
+}

examples/regression/src/app.rs

@@ -0,0 +1,61 @@
+use crate::pr_4091::Routes4091;
+use leptos::prelude::*;
+use leptos_meta::{MetaTags, *};
+use leptos_router::{
+    components::{Route, Router, Routes},
+    path,
+};
+
+pub fn shell(options: LeptosOptions) -> impl IntoView {
+    view! {
+        <!DOCTYPE html>
+        <html lang="en">
+            <head>
+                <meta charset="utf-8"/>
+                <meta name="viewport" content="width=device-width, initial-scale=1"/>
+                <AutoReload options=options.clone()/>
+                <HydrationScripts options/>
+                <MetaTags/>
+            </head>
+            <body>
+                <App/>
+            </body>
+        </html>
+    }
+}
+
+#[component]
+pub fn App() -> impl IntoView {
+    provide_meta_context();
+    let fallback = || view! { "Page not found." }.into_view();
+    view! {
+        <Stylesheet id="leptos" href="/pkg/regression.css"/>
+        <Router>
+            <main>
+                <Routes fallback>
+                    <Route path=path!("") view=HomePage/>
+                    <Routes4091/>
+                </Routes>
+            </main>
+        </Router>
+    }
+}
+
+#[server]
+async fn server_call() -> Result<(), ServerFnError> {
+    tokio::time::sleep(std::time::Duration::from_millis(1)).await;
+    Ok(())
+}
+
+#[component]
+fn HomePage() -> impl IntoView {
+    view! {
+        <Title text="Regression Tests"/>
+        <h1>"Listing of regression tests"</h1>
+        <nav>
+            <ul>
+                <li><a href="/4091/">"4091"</a></li>
+            </ul>
+        </nav>
+    }
+}

examples/regression/src/lib.rs

@@ -0,0 +1,10 @@
+pub mod app;
+mod pr_4091;
+
+#[cfg(feature = "hydrate")]
+#[wasm_bindgen::prelude::wasm_bindgen]
+pub fn hydrate() {
+    use app::*;
+    console_error_panic_hook::set_once();
+    leptos::mount::hydrate_body(App);
+}

examples/regression/src/main.rs

@@ -0,0 +1,37 @@
+#[cfg(feature = "ssr")]
+#[tokio::main]
+async fn main() {
+    use axum::Router;
+    use leptos::prelude::*;
+    use leptos_axum::{generate_route_list, LeptosRoutes};
+    use regression::app::{shell, App};
+
+    let conf = get_configuration(None).unwrap();
+    let addr = conf.leptos_options.site_addr;
+    let leptos_options = conf.leptos_options;
+    // Generate the list of routes in your Leptos App
+    let routes = generate_route_list(App);
+
+    let app = Router::new()
+        .leptos_routes(&leptos_options, routes, {
+            let leptos_options = leptos_options.clone();
+            move || shell(leptos_options.clone())
+        })
+        .fallback(leptos_axum::file_and_error_handler(shell))
+        .with_state(leptos_options);
+
+    // run our app with hyper
+    // `axum::Server` is a re-export of `hyper::Server`
+    println!("listening on http://{}", &addr);
+    let listener = tokio::net::TcpListener::bind(&addr).await.unwrap();
+    axum::serve(listener, app.into_make_service())
+        .await
+        .unwrap();
+}
+
+#[cfg(not(feature = "ssr"))]
+pub fn main() {
+    // no client-side main function
+    // unless we want this to work with e.g., Trunk for pure client-side testing
+    // see lib.rs for hydration function instead
+}

examples/regression/src/pr_4091.rs

@@ -0,0 +1,67 @@
+use leptos::{context::Provider, prelude::*};
+use leptos_router::{
+    components::{ParentRoute, Route, A},
+    nested_router::Outlet,
+    path,
+};
+
+// FIXME This should be a set rather than a naive vec for push and pop, as
+// it may be possible for unexpected token be popped/pushed on multi-level
+// navigation.  For basic naive tests it should be Fine(TM).
+#[derive(Clone)]
+struct Expectations(Vec<&'static str>);
+
+#[component]
+pub fn Routes4091() -> impl leptos_router::MatchNestedRoutes + Clone {
+    view! {
+        <ParentRoute path=path!("4091") view=Container>
+            <Route path=path!("") view=Root/>
+            <Route path=path!("test1") view=Test1/>
+        </ParentRoute>
+    }
+    .into_inner()
+}
+
+#[component]
+fn Container() -> impl IntoView {
+    let rw_signal = RwSignal::new(Expectations(Vec::new()));
+    provide_context(rw_signal);
+
+    view! {
+        <nav>
+            <ul>
+                <li><A href="./">"4091 Home"</A></li>
+                <li><A href="test1">"test1"</A></li>
+            </ul>
+        </nav>
+        <div id="result">{move || {
+            rw_signal.with(|ex| ex.0.iter().fold(String::new(), |a, b| a + b + " "))
+        }}</div>
+        <Provider value=rw_signal>
+            <Outlet/>
+        </Provider>
+    }
+}
+
+#[component]
+fn Root() -> impl IntoView {
+    view! {
+        <div>"This is Root"</div>
+    }
+}
+
+#[component]
+fn Test1() -> impl IntoView {
+    let signal = expect_context::<RwSignal<Expectations>>();
+
+    on_cleanup(move || {
+        signal.update(|ex| {
+            ex.0.pop();
+        });
+    });
+
+    view! {
+        {move || signal.update(|ex| ex.0.push("Test1"))}
+        <div>"This is Test1"</div>
+    }
+}

examples/regression/style/main.scss

@@ -0,0 +1,3 @@
+body {
+    font-family: sans-serif;
+}

leptos/src/form.rs

@@ -111,28 +111,39 @@ where
 
     let on_submit = {
         move |ev: SubmitEvent| {
-            if ev.default_prevented() {
-                return;
-            }
-
-            ev.prevent_default();
-
-            match ServFn::from_event(&ev) {
-                Ok(new_input) => {
-                    action.dispatch(new_input);
+            // request_animation_frame here schedules this event handler to run slightly later
+            // this means that this `submit` handler will run *after* any other `submit` handlers
+            // that have been added by the user. this is useful because it means that the user can
+            // add an `on:submit` handler and call `ev.prevent_default()` to prevent the form submission
+            //
+            // without this delay, this handler will always run before the user's handler (which was added
+            // later), which means the user can't prevent the form submission in the same way
+            //
+            // see https://github.com/leptos-rs/leptos/issues/3872
+            request_animation_frame(move || {
+                if ev.default_prevented() {
+                    return;
                 }
-                Err(err) => {
-                    crate::logging::error!(
-                        "Error converting form field into server function \
-                         arguments: {err:?}"
-                    );
-                    value.set(Some(Err(ServerFnErrorErr::Serialization(
-                        err.to_string(),
-                    )
-                    .into_app_error())));
-                    version.update(|n| *n += 1);
+
+                ev.prevent_default();
+
+                match ServFn::from_event(&ev) {
+                    Ok(new_input) => {
+                        action.dispatch(new_input);
+                    }
+                    Err(err) => {
+                        crate::logging::error!(
+                            "Error converting form field into server function \
+                             arguments: {err:?}"
+                        );
+                        value.set(Some(Err(ServerFnErrorErr::Serialization(
+                            err.to_string(),
+                        )
+                        .into_app_error())));
+                        version.update(|n| *n += 1);
+                    }
                 }
-            }
+            });
         }
     };
 

reactive_graph/src/owner.rs

@@ -167,7 +167,6 @@ impl Owner {
                     .map(|parent| parent.read().or_poisoned().arena.clone())
                     .unwrap_or_default(),
                 paused: false,
-                joined_owners: Vec::new(),
             })),
             #[cfg(feature = "hydration")]
             shared_context,
@@ -202,7 +201,6 @@ impl Owner {
                 #[cfg(feature = "sandboxed-arenas")]
                 arena: Default::default(),
                 paused: false,
-                joined_owners: Vec::new(),
             })),
             #[cfg(feature = "hydration")]
             shared_context,
@@ -228,7 +226,6 @@ impl Owner {
                 #[cfg(feature = "sandboxed-arenas")]
                 arena,
                 paused,
-                joined_owners: Vec::new(),
             })),
             #[cfg(feature = "hydration")]
             shared_context: self.shared_context.clone(),
@@ -464,7 +461,6 @@ pub(crate) struct OwnerInner {
     #[cfg(feature = "sandboxed-arenas")]
     arena: Arc<RwLock<ArenaMap>>,
     paused: bool,
-    joined_owners: Vec<WeakOwner>,
 }
 
 impl Debug for OwnerInner {

reactive_graph/src/owner/context.rs

@@ -6,15 +6,6 @@ use std::{
 };
 
 impl Owner {
-    #[doc(hidden)]
-    pub fn join_contexts(&self, other: &Owner) {
-        self.inner
-            .write()
-            .or_poisoned()
-            .joined_owners
-            .push(other.downgrade());
-    }
-
     fn provide_context<T: Send + Sync + 'static>(&self, value: T) {
         self.inner
             .write()
@@ -34,27 +25,18 @@ impl Owner {
         if let Some(context) = contexts.remove(&ty) {
             context.downcast::<T>().ok().map(|n| *n)
         } else {
-            let parent = inner.parent.as_ref().and_then(|p| p.upgrade());
-            let joined = inner
-                .joined_owners
-                .iter()
-                .flat_map(|owner| owner.upgrade().map(|owner| owner.inner));
-            for parent in parent.into_iter().chain(joined) {
-                let mut parent = Some(parent);
-                while let Some(ref this_parent) = parent.clone() {
-                    let mut this_parent = this_parent.write().or_poisoned();
-                    let contexts = &mut this_parent.contexts;
-                    let value = contexts.remove(&ty);
-                    let downcast =
-                        value.and_then(|context| context.downcast::<T>().ok());
-                    if let Some(value) = downcast {
-                        return Some(*value);
-                    } else {
-                        parent = this_parent
-                            .parent
-                            .as_ref()
-                            .and_then(|p| p.upgrade());
-                    }
+            let mut parent = inner.parent.as_ref().and_then(|p| p.upgrade());
+            while let Some(ref this_parent) = parent.clone() {
+                let mut this_parent = this_parent.write().or_poisoned();
+                let contexts = &mut this_parent.contexts;
+                let value = contexts.remove(&ty);
+                let downcast =
+                    value.and_then(|context| context.downcast::<T>().ok());
+                if let Some(value) = downcast {
+                    return Some(*value);
+                } else {
+                    parent =
+                        this_parent.parent.as_ref().and_then(|p| p.upgrade());
                 }
             }
             None
@@ -71,29 +53,21 @@ impl Owner {
         let reference = if let Some(context) = contexts.get(&ty) {
             context.downcast_ref::<T>()
         } else {
-            let parent = inner.parent.as_ref().and_then(|p| p.upgrade());
-            let joined = inner
-                .joined_owners
-                .iter()
-                .flat_map(|owner| owner.upgrade().map(|owner| owner.inner));
-            for parent in parent.into_iter().chain(joined) {
-                let mut parent = Some(parent);
-                while let Some(ref this_parent) = parent.clone() {
-                    let this_parent = this_parent.read().or_poisoned();
-                    let contexts = &this_parent.contexts;
-                    let value = contexts.get(&ty);
-                    let downcast =
-                        value.and_then(|context| context.downcast_ref::<T>());
-                    if let Some(value) = downcast {
-                        return Some(cb(value));
-                    } else {
-                        parent = this_parent
-                            .parent
-                            .as_ref()
-                            .and_then(|p| p.upgrade());
-                    }
+            let mut parent = inner.parent.as_ref().and_then(|p| p.upgrade());
+            while let Some(ref this_parent) = parent.clone() {
+                let this_parent = this_parent.read().or_poisoned();
+                let contexts = &this_parent.contexts;
+                let value = contexts.get(&ty);
+                let downcast =
+                    value.and_then(|context| context.downcast_ref::<T>());
+                if let Some(value) = downcast {
+                    return Some(cb(value));
+                } else {
+                    parent =
+                        this_parent.parent.as_ref().and_then(|p| p.upgrade());
                 }
             }
+
             None
         };
         reference.map(cb)
@@ -109,27 +83,18 @@ impl Owner {
         let reference = if let Some(context) = contexts.get_mut(&ty) {
             context.downcast_mut::<T>()
         } else {
-            let parent = inner.parent.as_ref().and_then(|p| p.upgrade());
-            let joined = inner
-                .joined_owners
-                .iter()
-                .flat_map(|owner| owner.upgrade().map(|owner| owner.inner));
-            for parent in parent.into_iter().chain(joined) {
-                let mut parent = Some(parent);
-                while let Some(ref this_parent) = parent.clone() {
-                    let mut this_parent = this_parent.write().or_poisoned();
-                    let contexts = &mut this_parent.contexts;
-                    let value = contexts.get_mut(&ty);
-                    let downcast =
-                        value.and_then(|context| context.downcast_mut::<T>());
-                    if let Some(value) = downcast {
-                        return Some(cb(value));
-                    } else {
-                        parent = this_parent
-                            .parent
-                            .as_ref()
-                            .and_then(|p| p.upgrade());
-                    }
+            let mut parent = inner.parent.as_ref().and_then(|p| p.upgrade());
+            while let Some(ref this_parent) = parent.clone() {
+                let mut this_parent = this_parent.write().or_poisoned();
+                let contexts = &mut this_parent.contexts;
+                let value = contexts.get_mut(&ty);
+                let downcast =
+                    value.and_then(|context| context.downcast_mut::<T>());
+                if let Some(value) = downcast {
+                    return Some(cb(value));
+                } else {
+                    parent =
+                        this_parent.parent.as_ref().and_then(|p| p.upgrade());
                 }
             }
             None