[Fix] Allowing for a following / on paths

mtp-webserver/src/http.rs

@@ -97,4 +97,36 @@ mod tests {
             StatusCode::CREATED
         );
     }
+
+    #[tokio::test]
+    async fn dispatch_matches_terminal_slashes_for_exact_and_pattern_routes() {
+        let router = Router::new()
+            .route("/api", |_, response| async move {
+                response.status(StatusCode::ACCEPTED)
+            })
+            .unwrap()
+            .route_pattern("/api/test/{id}", |_, response, _| async move {
+                response.status(StatusCode::CREATED)
+            })
+            .unwrap()
+            .fallback(|_, response| async move { response.status(StatusCode::IM_A_TEAPOT) })
+            .unwrap();
+
+        for uri in ["/api/test", "/api/test/"] {
+            assert_eq!(
+                dispatch_request(request(Method::GET, uri), &router)
+                    .await
+                    .status,
+                StatusCode::ACCEPTED
+            );
+        }
+        for uri in ["/api/test/1", "/api/test/1/"] {
+            assert_eq!(
+                dispatch_request(request(Method::GET, uri), &router)
+                    .await
+                    .status,
+                StatusCode::CREATED
+            );
+        }
+    }
 }

mtp-webserver/src/router.rs

@@ -150,6 +150,7 @@ impl Router {
         path: String,
         handler: HttpHandler,
     ) -> Result<Self, RouterError> {
+        let path = normalize_path(&path);
         if self
             .routes
             .insert((method, path.clone()), handler)
@@ -166,6 +167,7 @@ impl Router {
         pattern: String,
         handler: DynamicHttpHandler,
     ) -> Result<Self, RouterError> {
+        let pattern = normalize_path(&pattern);
         let segments = parse_pattern(&pattern)?;
         if self
             .pattern_routes
@@ -189,9 +191,10 @@ impl Router {
     }
 
     pub(crate) fn handler(&self, method: &Method, path: &str) -> Option<HttpHandler> {
+        let path = normalize_path(path);
         self.routes
-            .get(&(Some(method.clone()), path.to_string()))
+            .get(&(Some(method.clone()), path.clone()))
-            .or_else(|| self.routes.get(&(None, path.to_string())))
+            .or_else(|| self.routes.get(&(None, path)))
             .cloned()
     }
 
@@ -200,10 +203,11 @@ impl Router {
         method: &Method,
         path: &str,
     ) -> Option<(DynamicHttpHandler, RouteParams)> {
+        let path = normalize_path(path);
         self.pattern_routes
             .iter()
             .filter(|route| route.method.is_none() || route.method.as_ref() == Some(method))
-            .filter_map(|route| match_pattern(&route.segments, path).map(|params| (route, params)))
+            .filter_map(|route| match_pattern(&route.segments, &path).map(|params| (route, params)))
             .max_by_key(|(route, _)| (route.method.is_some(), route.static_segments))
             .map(|(route, params)| (route.handler.clone(), params))
     }
@@ -212,6 +216,25 @@ impl Router {
     }
 }
 
+/// Canonicalize a route path for matching.
+///
+/// HTTP request paths are absolute, but accepting an omitted leading slash in
+/// route registration is convenient. A terminal slash (or several terminal
+/// slashes) does not identify a different resource, except for the root path.
+fn normalize_path(path: &str) -> String {
+    let path = if path.starts_with('/') {
+        path.to_string()
+    } else {
+        format!("/{path}")
+    };
+    let normalized = path.trim_end_matches('/');
+    if normalized.is_empty() {
+        "/".to_string()
+    } else {
+        normalized.to_string()
+    }
+}
+
 fn parse_pattern(pattern: &str) -> Result<Vec<PatternSegment>, RouterError> {
     let path = pattern.strip_prefix('/').unwrap_or(pattern);
     let path = path.strip_suffix('/').unwrap_or(path);