minify: minify html on the fly in release mode

crates/ezidam/Cargo.toml

@@ -16,6 +16,7 @@ rocket_cors = "0.6.0-alpha2"
 email_address = { workspace = true }
 chrono-tz = "0.8.2"
 chrono-humanize = "0.2.2"
+minify-html = "0.10.8"
 
 # local crates
 database_pool = { path = "../database_pool" }

crates/ezidam/src/lib.rs

@@ -10,6 +10,7 @@ mod guards;
 mod icons;
 mod id;
 mod menu;
+mod minify;
 mod oauth;
 mod page;
 mod response_timer;
@@ -18,6 +19,7 @@ mod shutdown;
 mod tokens;
 
 pub use crate::email::init as email_init;
+use crate::minify::Minify;
 
 pub fn rocket_setup(rocket_builder: Rocket<Build>) -> Rocket<Build> {
     use cache::CacheControl;
@@ -46,6 +48,9 @@ pub fn rocket_setup(rocket_builder: Rocket<Build>) -> Rocket<Build> {
     // Static assets
     let rocket_builder = rocket_builder.mount("/", FileServer::from("static"));
 
+    // Minify content
+    let rocket_builder = Minify::rocket(rocket_builder);
+
     // Routes
     let rocket_builder = routes::routes(rocket_builder);
 

crates/ezidam/src/minify.rs

@@ -0,0 +1,49 @@
+use rocket::fairing::{self, Fairing, Kind};
+use rocket::http::ContentType;
+use rocket::{Build, Request, Response, Rocket};
+
+pub struct Minify {}
+
+impl Minify {
+    pub fn rocket(rocket_builder: Rocket<Build>) -> Rocket<Build> {
+        if cfg!(debug_assertions) {
+            rocket_builder
+        } else {
+            rocket_builder.attach(Self {})
+        }
+    }
+}
+
+#[rocket::async_trait]
+impl Fairing for Minify {
+    fn info(&self) -> fairing::Info {
+        fairing::Info {
+            name: "Minify HTML",
+            kind: Kind::Response,
+        }
+    }
+
+    async fn on_response<'r>(&self, _request: &'r Request<'_>, response: &mut Response<'r>) {
+        if response.content_type() == Some(ContentType::HTML) {
+            let body = response.body_mut();
+
+            if let Ok(original) = body.to_bytes().await {
+                let cfg = minify_html::Cfg {
+                    // Be HTML spec compliant
+                    do_not_minify_doctype: true,
+                    ensure_spec_compliant_unquoted_attribute_values: true,
+                    keep_spaces_between_attributes: true,
+
+                    // The rest
+                    keep_closing_tags: true,
+                    keep_html_and_head_opening_tags: true,
+                    minify_css: true,
+                    minify_js: true,
+                    ..Default::default()
+                };
+                let minified = minify_html::minify(&original, &cfg);
+                response.set_sized_body(minified.len(), std::io::Cursor::new(minified));
+            }
+        }
+    }
+}