fix(api): implement TryFromConn for Vec<u8> and String

instead of using the FromConn blanket impl with Error = ();

api/src/from_conn.rs

@@ -1,6 +1,5 @@
-use trillium::{async_trait, Conn};
-
 use crate::TryFromConn;
+use trillium::{async_trait, Conn};
 
 /// A trait to extract content from [`Conn`]s to be used as the second
 /// argument to an api handler. Implement this for your types.
@@ -18,20 +17,6 @@ impl FromConn for () {
     }
 }
 
-#[async_trait]
-impl FromConn for String {
-    async fn from_conn(conn: &mut Conn) -> Option<Self> {
-        conn.request_body_string().await.ok()
-    }
-}
-
-#[async_trait]
-impl FromConn for Vec<u8> {
-    async fn from_conn(conn: &mut Conn) -> Option<Self> {
-        conn.request_body().await.read_bytes().await.ok()
-    }
-}
-
 #[async_trait]
 impl<E: FromConn> FromConn for Option<E> {
     async fn from_conn(conn: &mut Conn) -> Option<Self> {

api/src/try_from_conn.rs

@@ -34,6 +34,26 @@ impl<T: FromConn> TryFromConn for T {
     }
 }
 
+#[async_trait]
+impl TryFromConn for Vec<u8> {
+    type Error = crate::Error;
+    async fn try_from_conn(conn: &mut Conn) -> Result<Self, Self::Error> {
+        conn.request_body()
+            .await
+            .read_bytes()
+            .await
+            .map_err(Into::into)
+    }
+}
+
+#[async_trait]
+impl TryFromConn for String {
+    type Error = crate::Error;
+    async fn try_from_conn(conn: &mut Conn) -> Result<Self, Self::Error> {
+        conn.request_body_string().await.map_err(Into::into)
+    }
+}
+
 #[cfg(feature = "url")]
 #[async_trait]
 impl TryFromConn for url::Url {