Add ability to lookup mux handle

Author: raphael

design/validation.go

@@ -211,8 +211,10 @@ func (r *ResourceDefinition) Validate() *ValidationErrors {
 	if r.Params != nil {
 		verr.Merge(r.Params.Validate("resource parameters", r))
 	}
-	if err := CanUse(r, Design); err != nil {
-		verr.Add(r, "Invalid API version in list")
+	if !r.SupportsNoVersion() {
+		if err := CanUse(r, Design); err != nil {
+			verr.Add(r, "Invalid API version in list")
+		}
 	}
 	return verr.AsError()
 }

goagen/gen_app/generator.go

@@ -86,7 +86,10 @@ func (g *Generator) Generate(api *design.APIDefinition) (_ []string, err error)
 
 	outdir := AppOutputDir()
 	err = api.IterateVersions(func(v *design.APIVersionDefinition) error {
-		verdir := filepath.Join(outdir, codegen.VersionPackage(v.Version))
+		verdir := outdir
+		if v.Version != "" {
+			verdir = filepath.Join(verdir, codegen.VersionPackage(v.Version))
+		}
 		if err := os.MkdirAll(verdir, 0755); err != nil {
 			return err
 		}

mux.go

@@ -34,6 +34,8 @@ type (
 		http.Handler
 		// Handle sets the HandleFunc for a given HTTP method and path.
 		Handle(method, path string, handle HandleFunc)
+		// Lookup returns the HandleFunc associated with the given HTTP method and path.
+		Lookup(method, path string) HandleFunc
 	}
 
 	// HandleFunc provides the implementation for an API endpoint.
@@ -57,15 +59,19 @@ type (
 
 	// defaultVersionMux is the default goa API version specific mux.
 	defaultVersionMux struct {
-		router *httprouter.Router
+		router  *httprouter.Router
+		handles map[string]HandleFunc
 	}
 )
 
 // NewMux creates a top level mux using the default goa mux implementation.
 func NewMux() ServeMux {
 	return &DefaultMux{
-		defaultVersionMux: &defaultVersionMux{router: httprouter.New()},
-		selectVersion:     PathSelectVersionFunc("/:version"),
+		defaultVersionMux: &defaultVersionMux{
+			router:  httprouter.New(),
+			handles: make(map[string]HandleFunc),
+		},
+		selectVersion: PathSelectVersionFunc("/:version"),
 	}
 }
 
@@ -173,9 +179,15 @@ func (m *defaultVersionMux) Handle(method, path string, handle HandleFunc) {
 		}
 		handle(rw, req, params)
 	}
+	m.handles[method+path] = handle
 	m.router.Handle(method, path, hthandle)
 }
 
+// Lookup returns the HandleFunc associated with the given method and path.
+func (m *defaultVersionMux) Lookup(method, path string) HandleFunc {
+	return m.handles[method+path]
+}
+
 // ServeHTTP is the function called back by the underlying HTTP server to handle incoming requests.
 func (m *defaultVersionMux) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	m.router.ServeHTTP(rw, req)