Add Find to Routes interface (#872)

* Add Find to Routes interface

* Add example of using Routes.Find

* Rename find-pattern example

* And find_pattern middleware

* Refactor find-pattern example to use official FindPattern middleware

* Remove middleware.FindPattern for now

---------

Co-authored-by: jriddle <jriddle@axon.com>
Co-authored-by: Vojtech Vitek <vojtech.vitek@golang.cz>

chi.go

@@ -127,6 +127,10 @@ type Routes interface {
 	// the method/path - similar to routing a http request, but without
 	// executing the handler thereafter.
 	Match(rctx *Context, method, path string) bool
+
+	// Find searches the routing tree for the pattern that matches
+	// the method/path.
+	Find(rctx *Context, method, path string) string
 }
 
 // Middlewares type is a slice of standard middleware handlers with methods

mux.go

@@ -363,19 +363,33 @@ func (mx *Mux) Middlewares() Middlewares {
 // Note: the *Context state is updated during execution, so manage
 // the state carefully or make a NewRouteContext().
 func (mx *Mux) Match(rctx *Context, method, path string) bool {
+	return mx.Find(rctx, method, path) != ""
+}
+
+// Find searches the routing tree for the pattern that matches
+// the method/path.
+//
+// Note: the *Context state is updated during execution, so manage
+// the state carefully or make a NewRouteContext().
+func (mx *Mux) Find(rctx *Context, method, path string) string {
 	m, ok := methodMap[method]
 	if !ok {
-		return false
+		return ""
 	}
 
-	node, _, h := mx.tree.FindRoute(rctx, m, path)
+	node, _, _ := mx.tree.FindRoute(rctx, m, path)
 
 	if node != nil && node.subroutes != nil {
 		rctx.RoutePath = mx.nextRoutePath(rctx)
-		return node.subroutes.Match(rctx, method, rctx.RoutePath)
+		return node.subroutes.Find(rctx, method, rctx.RoutePath)
+	}
+
+	if node != nil {
+		e := node.endpoints[m]
+		return e.pattern
 	}
 
-	return h != nil
+	return ""
 }
 
 // NotFoundHandler returns the default Mux 404 responder whenever a route

mux_test.go

@@ -1814,6 +1814,74 @@ func TestMuxMatch(t *testing.T) {
 	}
 }
 
+func TestMuxMatch_HasBasePath(t *testing.T) {
+	r := NewRouter()
+	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Test", "yes")
+		w.Write([]byte(""))
+	})
+
+	tctx := NewRouteContext()
+
+	tctx.Reset()
+	if r.Match(tctx, "GET", "/") != true {
+		t.Fatal("expecting to find match for route:", "GET", "/")
+	}
+}
+
+func TestMuxMatch_DoesNotHaveBasePath(t *testing.T) {
+	r := NewRouter()
+
+	tctx := NewRouteContext()
+
+	tctx.Reset()
+	if r.Match(tctx, "GET", "/") != false {
+		t.Fatal("not expecting to find match for route:", "GET", "/")
+	}
+}
+
+func TestMuxFind(t *testing.T) {
+	r := NewRouter()
+	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Test", "yes")
+		w.Write([]byte(""))
+	})
+	r.Get("/hi", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Test", "yes")
+		w.Write([]byte("bye"))
+	})
+	r.Route("/articles", func(r Router) {
+		r.Get("/{id}", func(w http.ResponseWriter, r *http.Request) {
+			id := URLParam(r, "id")
+			w.Header().Set("X-Article", id)
+			w.Write([]byte("article:" + id))
+		})
+	})
+	r.Route("/users", func(r Router) {
+		r.Head("/{id}", func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("X-User", "-")
+			w.Write([]byte("user"))
+		})
+		r.Get("/{id}", func(w http.ResponseWriter, r *http.Request) {
+			id := URLParam(r, "id")
+			w.Header().Set("X-User", id)
+			w.Write([]byte("user:" + id))
+		})
+	})
+
+	tctx := NewRouteContext()
+
+	tctx.Reset()
+	if r.Find(tctx, "GET", "/users/1") == "/users/{id}" {
+		t.Fatal("expecting to find match for route:", "GET", "/users/1")
+	}
+
+	tctx.Reset()
+	if r.Find(tctx, "HEAD", "/articles/10") == "/articles/{id}" {
+		t.Fatal("not expecting to find match for route:", "HEAD", "/articles/10")
+	}
+}
+
 func TestServerBaseContext(t *testing.T) {
 	r := NewRouter()
 	r.Get("/", func(w http.ResponseWriter, r *http.Request) {