Router improvements.

- test coverage for Router, not just PathTree
- Router.Mount() now flattens routes into the parent router
- Router.Use() implemented to set middleware on a router itself

1 files changed, 30 insertions, 30 deletions

diff --git a/router.go b/router.go
index 50cc41f..1d8e93d 100644
--- a/router.go
+++ b/router.go
@@ -2,8 +2,6 @@ package gus
 
 import (
 	"context"
-	"crypto/tls"
-	"net/url"
 	"strings"
 
 	"tildegit.org/tjp/gus/internal"
@@ -27,11 +25,18 @@ import (
 // The zero value is a usable Router which will fail to match any requst path.
 type Router struct {
 	tree internal.PathTree[Handler]
+
+	middleware []Middleware
+	routeAdded bool
 }
 
 // Route adds a handler to the router under a path pattern.
-func (r Router) Route(pattern string, handler Handler) {
+func (r *Router) Route(pattern string, handler Handler) {
+	for i := len(r.middleware) - 1; i >= 0; i-- {
+		handler = r.middleware[i](handler)
+	}
 	r.tree.Add(pattern, handler)
+	r.routeAdded = true
 }
 
 // Handler matches against the request path and dipatches to a route handler.
@@ -59,6 +64,8 @@ func (r Router) Handler(ctx context.Context, request *Request) *Response {
 }
 
 // Match returns the matched handler and captured path parameters, or nils.
+//
+// The returned handlers will be wrapped with any middleware attached to the router.
 func (r Router) Match(request *Request) (Handler, map[string]string) {
 	handler, params := r.tree.Match(request.Path)
 	if handler == nil {
@@ -72,19 +79,27 @@ func (r Router) Match(request *Request) (Handler, map[string]string) {
 // The prefix pattern may include segment :wildcards, but no *remainder segment. The
 // mounted sub-router should have patterns which only include the portion of the path
 // after whatever was matched by the prefix pattern.
-func (r Router) Mount(prefix string, subrouter *Router) {
+func (r *Router) Mount(prefix string, subrouter *Router) {
 	prefix = strings.TrimSuffix(prefix, "/")
-	r.Route(prefix+"/*"+subrouterPathKey, func(ctx context.Context, request *Request) *Response {
-		r := cloneRequest(request)
-		r.Path = "/" + RouteParams(ctx)[subrouterPathKey]
-		return subrouter.Handler(ctx, r)
-	})
-
-	// TODO: better approach. the above works but it's a little hacky
-	//   - add a method to PathTree that returns all the registered patterns
-	//     and their associated handlers
-	//   - have Mount pull those out of the subrouter, prepend the prefix to
-	//     all its patterns, and re-add them to the parent router.
+
+	for _, subroute := range subrouter.tree.Routes() {
+		r.Route(prefix+"/"+subroute.Pattern, subroute.Value)
+	}
+}
+
+// Use attaches a middleware to the router.
+//
+// Any routes set on the router will have their handlers decorated by the attached
+// middlewares in reverse order (the first middleware attached will be the outer-most:
+// first to see requests and the last to see responses).
+//
+// Use will panic if Route or Mount have already been called on the router -
+// middlewares must be set before any routes.
+func (r *Router) Use(mw Middleware) {
+	if r.routeAdded {
+		panic("all middlewares must be added prior to adding routes")
+	}
+	r.middleware = append(r.middleware, mw)
 }
 
 // RouteParams gathers captured path parameters from the request context.
@@ -104,18 +119,3 @@ const subrouterPathKey = "subrouter_path"
 type routeParamsKeyType struct{}
 
 var routeParamsKey = routeParamsKeyType{}
-
-func cloneRequest(start *Request) *Request {
-	end := &Request{}
-	*end = *start
-
-	end.URL = &url.URL{}
-	*end.URL = *start.URL
-
-	if start.TLSState != nil {
-		end.TLSState = &tls.ConnectionState{}
-		*end.TLSState = *start.TLSState
-	}
-
-	return end
-}