vendor assets with versionning

e2e/tests/websocket.spec.ts

@@ -20,12 +20,25 @@ test("a list updates live for another user via websocket", async ({ page, browse
   // Give the websocket connections a moment to establish.
   await page.waitForTimeout(500);
 
+  // Both start with an empty list.
+  await expect(pageB.locator("#list-meta")).toHaveText("0 items left out of 0");
+
   // User A adds an item.
   await addItem(page, "Apple", "2");
 
   // It should appear on User B's page without any reload.
   await expect(pageB.locator(".item-row").filter({ hasText: "Apple" })).toBeVisible();
   await expect(pageB.locator(".item-row").filter({ hasText: "Apple" }).locator(".item-qty")).toHaveText("(2)");
+  // The left/total count should also update live for User B.
+  await expect(pageB.locator("#list-meta")).toHaveText("1 items left out of 1");
+
+  // User A removes the item.
+  await page.locator(".item-actions-button").first().click();
+  await page.locator("[id^='item-edit-delete']").click();
+
+  // The item and the count should update live on User B's page.
+  await expect(pageB.locator(".item-row").filter({ hasText: "Apple" })).toHaveCount(0);
+  await expect(pageB.locator("#list-meta")).toHaveText("0 items left out of 0");
 
   await contextB.close();
 });

src/assets.rs

@@ -0,0 +1,79 @@
+use std::collections::HashMap;
+use std::sync::LazyLock;
+
+use sha2::{Digest, Sha256};
+
+/// A single static asset: its embedded bytes and a content hash used to
+/// version its URL.
+pub struct StaticAsset {
+    pub data: &'static [u8],
+    pub hash: String,
+}
+
+/// A registry of the app's static assets, keyed by filename. Each asset's
+/// content hash is computed once on first use and cached, so the versioned URL
+/// changes automatically whenever the underlying file changes.
+pub struct StaticAssetStore {
+    assets: HashMap<&'static str, StaticAsset>,
+}
+
+impl StaticAssetStore {
+    fn new(entries: &[(&'static str, &'static [u8])]) -> Self {
+        let assets = entries
+            .iter()
+            .map(|(name, data)| {
+                let hash = content_hash(data);
+                (*name, StaticAsset { data, hash })
+            })
+            .collect();
+        Self { assets }
+    }
+
+    /// Looks up an asset by its filename (e.g. `"style.css"`).
+    pub fn get(&self, name: &str) -> Option<&StaticAsset> {
+        self.assets.get(name)
+    }
+
+    /// Returns the versioned URL for an asset, e.g. `/static/style.css?v=<hash>`.
+    pub fn url(&self, name: &str) -> Option<String> {
+        self.assets
+            .get(name)
+            .map(|asset| format!("/static/{name}?v={}", asset.hash))
+    }
+}
+
+fn content_hash(data: &[u8]) -> String {
+    let mut hasher = Sha256::new();
+    hasher.update(data);
+    hex::encode(hasher.finalize())
+}
+
+/// Constructs a `StaticAssetStore` from `name => path` pairs, embedding each
+/// file's bytes at compile time via `include_bytes!`.
+macro_rules! static_assets {
+    ($($name:literal => $path:literal),* $(,)?) => {
+        StaticAssetStore::new(&[
+            $(($name, include_bytes!($path))),*
+        ])
+    };
+}
+
+/// The app's static assets, loaded once on first use.
+pub static STORE: LazyLock<StaticAssetStore> = LazyLock::new(|| {
+    static_assets! {
+        "style.css" => "../static/style.css",
+        "passkey-login.js" => "../static/passkey-login.js",
+        "passkey-register.js" => "../static/passkey-register.js",
+        "password-toggle.js" => "../static/password-toggle.js",
+        "htmx.min.js" => "../static/htmx.min.js",
+        "htmx-ws.min.js" => "../static/htmx-ws.min.js",
+    }
+});
+
+/// Returns the versioned URL for a known asset, panicking if the name isn't
+/// registered (a programmer error, since these are compile-time constants).
+pub fn url(name: &str) -> String {
+    STORE
+        .url(name)
+        .unwrap_or_else(|| panic!("unknown static asset: {name}"))
+}

src/http.rs

@@ -20,19 +20,13 @@ use thiserror::Error;
 use tower_http::trace::{DefaultMakeSpan, DefaultOnResponse, TraceLayer};
 use tracing::{Level, error, warn};
 
+use crate::assets;
 use crate::domain::{DomainError, SessionUser};
 use crate::ports::{HubEvent, RealtimeNotifier};
 use crate::services::{AuthService, InvitationService, ListService, MealService};
 use crate::views;
 use crate::webauthn::WebAuthnService;
 
-/// The contents of `static/`, embedded into the binary at compile time so the
-/// app can be shipped as a single executable without a separate static directory.
-const STYLE_CSS: &[u8] = include_bytes!("../static/style.css");
-const PASSKEY_LOGIN_JS: &[u8] = include_bytes!("../static/passkey-login.js");
-const PASSKEY_REGISTER_JS: &[u8] = include_bytes!("../static/passkey-register.js");
-const PASSWORD_TOGGLE_JS: &[u8] = include_bytes!("../static/password-toggle.js");
-
 #[derive(Clone)]
 pub struct AppState {
     pub auth: Arc<AuthService>,
@@ -340,15 +334,24 @@ async fn home() -> Redirect {
 }
 
 /// Serves a file embedded in the binary from the `static/` folder.
+///
+/// Every asset is served with an immutable, long-lived cache header. Because
+/// the HTML references each asset under a URL that is versioned by its content
+/// hash, a changed file gets a new URL and the cache is never stale.
 async fn static_asset(Path(path): Path<String>) -> Response {
-    let (mime, data) = match path.as_str() {
-        "style.css" => ("text/css", STYLE_CSS),
-        "passkey-login.js" => ("application/javascript", PASSKEY_LOGIN_JS),
-        "passkey-register.js" => ("application/javascript", PASSKEY_REGISTER_JS),
-        "password-toggle.js" => ("application/javascript", PASSWORD_TOGGLE_JS),
-        _ => return StatusCode::NOT_FOUND.into_response(),
+    let Some(asset) = assets::STORE.get(&path) else {
+        return StatusCode::NOT_FOUND.into_response();
     };
-    ([(header::CONTENT_TYPE, mime)], data).into_response()
+    let mime = match path.as_str() {
+        "style.css" => "text/css",
+        _ => "application/javascript",
+    };
+    let mut response = ([(header::CONTENT_TYPE, mime)], asset.data).into_response();
+    response.headers_mut().insert(
+        header::CACHE_CONTROL,
+        HeaderValue::from_static("public, max-age=31536000, immutable"),
+    );
+    response
 }
 
 async fn log_response_status(request: Request, next: Next) -> Response {

src/main.rs

@@ -1,3 +1,4 @@
+mod assets;
 mod domain;
 mod http;
 mod hub;

src/views.rs

@@ -37,8 +37,8 @@ pub fn login_page(error: Option<&str>, invite: Option<&str>) -> Markup {
                 button id="passkey-login" class="button button-secondary" type="button" { "Sign in with a passkey" }
                 p class="auth-switch" { "Need an account? " a href="/register" { "Create one" } }
             }
-            script src="/static/password-toggle.js" {}
-            script src="/static/passkey-login.js" {}
+            script src=(crate::assets::url("password-toggle.js")) {}
+            script src=(crate::assets::url("passkey-login.js")) {}
         },
     )
 }
@@ -72,7 +72,7 @@ pub fn register_page(error: Option<&str>, invite: Option<&str>) -> Markup {
                 }
                 p class="auth-switch" { "Already have an account? " a href="/login" { "Sign in" } }
             }
-            script src="/static/password-toggle.js" {}
+            script src=(crate::assets::url("password-toggle.js")) {}
         },
     )
 }
@@ -164,8 +164,8 @@ pub fn account_page(
                     }
                 }
             }
-            script src="/static/password-toggle.js" {}
-            script src="/static/passkey-register.js" {}
+            script src=(crate::assets::url("password-toggle.js")) {}
+            script src=(crate::assets::url("passkey-register.js")) {}
         },
     )
 }
@@ -795,7 +795,7 @@ pub fn list_page(
                         div {
                             p class="eyebrow" { "SHARED LIST" }
                             h1 { (list.name) }
-                            p class="list-meta" { (items.iter().filter(|item| !item.checked).count()) " items to get" }
+                            (list_meta_fragment(items, false))
                         }
                         div class="list-topbar-actions" {
                             @if list.archived_at.is_some() {
@@ -1095,6 +1095,21 @@ pub fn categories_panel(categories: &[Category], csrf_token: &str, out_of_band:
     }
 }
 
+fn list_meta_fragment(items: &[Item], out_of_band: bool) -> Markup {
+    let left = items.iter().filter(|item| !item.checked).count();
+    let total = items.len();
+    let meta = html! {
+        p id="list-meta" class="list-meta" { (left) " items left out of " (total) }
+    };
+    if out_of_band {
+        html! {
+            p id="list-meta" class="list-meta" hx-swap-oob="outerHTML" { (left) " items left out of " (total) }
+        }
+    } else {
+        meta
+    }
+}
+
 pub fn live_list_fragments(
     list: &GroceryList,
     items: &[Item],
@@ -1104,6 +1119,7 @@ pub fn live_list_fragments(
 ) -> Markup {
     let editable = list.archived_at.is_none();
     html! {
+        (list_meta_fragment(items, true))
         (list_items_fragment(list, items, categories, csrf_token, true, editable))
         (list_meals_panel(list_meals, list.id, csrf_token, true, editable))
     }
@@ -1292,9 +1308,9 @@ fn page(title: &str, user: Option<&User>, content: Markup) -> Markup {
                 meta charset="utf-8";
                 meta name="viewport" content="width=device-width, initial-scale=1";
                 title { (title) " · Sustenance" }
-                link rel="stylesheet" href="/static/style.css";
-                script src="https://unpkg.com/htmx.org@2.0.10" {}
-                script src="https://unpkg.com/htmx-ext-ws@2.0.4/ws.js" {}
+                link rel="stylesheet" href=(crate::assets::url("style.css"));
+                script src=(crate::assets::url("htmx.min.js")) {}
+                script src=(crate::assets::url("htmx-ws.min.js")) {}
             }
             body hx-boost="true" {
                 header class="site-header" {