Set `charset` params on returned content types.

This is a somewhat indirect change; it removes `mime_guess` in favour of some very, uh, "bespoke" mime detection logic that hardcodes mime types for the small repertoire of file extensions actually present in the UI. `mime_guess` doesn't provide a way to set params as it exports its own `Mime` struct, which doesn't provide `with_params()`.

1 files changed, 26 insertions, 6 deletions

diff --git a/src/ui/assets.rs b/src/ui/assets.rs
index 342ba59..6a7563a 100644
--- a/src/ui/assets.rs
+++ b/src/ui/assets.rs
@@ -1,29 +1,31 @@
+use ::mime::{FromStrError, Mime};
 use axum::{
     http::{header, StatusCode},
     response::{IntoResponse, Response},
 };
-use mime_guess::Mime;
 use rust_embed::EmbeddedFile;
 
-use crate::{error::Internal, ui::error::NotFound};
+use super::{error::NotFound, mime};
+use crate::error::Internal;
 
 #[derive(rust_embed::Embed)]
 #[folder = "target/ui"]
 pub struct Assets;
 
 impl Assets {
-    pub fn load(path: impl AsRef<str>) -> Result<Asset, NotFound<String>> {
+    pub fn load(path: impl AsRef<str>) -> Result<Asset, Error> {
         let path = path.as_ref();
-        let mime = mime_guess::from_path(path).first_or_octet_stream();
+        let mime = mime::from_path(path)?;
 
         Self::get(path)
             .map(|file| Asset(mime, file))
-            .ok_or(NotFound(format!("not found: {path}")))
+            .ok_or(Error::NotFound(path.into()))
     }
 
     pub fn index() -> Result<Asset, Internal> {
         // "not found" in this case really is an internal error, as it should
-        // never happen. `index.html` is a known-valid path.
+        // never happen. `index.html` is a known-valid path with a known-valid
+        // file extension.
         Ok(Self::load("index.html")?)
     }
 }
@@ -41,3 +43,21 @@ impl IntoResponse for Asset {
             .into_response()
     }
 }
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("not found: {0}")]
+    NotFound(String),
+    #[error(transparent)]
+    Mime(#[from] FromStrError),
+}
+
+impl IntoResponse for Error {
+    fn into_response(self) -> Response {
+        #[allow(clippy::match_wildcard_for_single_variants)]
+        match self {
+            Self::NotFound(_) => NotFound(self.to_string()).into_response(),
+            other => Internal::from(other).into_response(),
+        }
+    }
+}