Allow servers to return DAV capabilities in OPTIONS

carddav/server.go

@@ -214,22 +214,29 @@ type backend struct {
 	Backend Backend
 }
 
-func (b *backend) Options(r *http.Request) ([]string, error) {
+func (b *backend) Options(r *http.Request) (caps []string, allow []string, err error) {
-	// TODO: add DAV: addressbook
+	caps = []string{"addressbook"}
 
 	if r.URL.Path == "/" {
-		return []string{http.MethodOptions, "PROPFIND"}, nil
+		return caps, []string{http.MethodOptions, "PROPFIND", "REPORT"}, nil
 	}
 
 	var dataReq AddressDataRequest
-	_, err := b.Backend.GetAddressObject(r.URL.Path, &dataReq)
+	_, err = b.Backend.GetAddressObject(r.URL.Path, &dataReq)
 	if httpErr, ok := err.(*internal.HTTPError); ok && httpErr.Code == http.StatusNotFound {
-		return []string{http.MethodOptions}, nil
+		return caps, []string{http.MethodOptions, http.MethodPut}, nil
 	} else if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
-	return []string{http.MethodOptions, http.MethodHead, http.MethodGet, "PROPFIND"}, nil
+	return caps, []string{
+		http.MethodOptions,
+		http.MethodHead,
+		http.MethodGet,
+		http.MethodPut,
+		http.MethodDelete,
+		"PROPFIND",
+	}, nil
 }
 
 func (b *backend) HeadGet(w http.ResponseWriter, r *http.Request) error {

internal/server.go

@@ -75,7 +75,7 @@ func ServeMultistatus(w http.ResponseWriter, ms *Multistatus) error {
 }
 
 type Backend interface {
-	Options(r *http.Request) ([]string, error)
+	Options(r *http.Request) (caps []string, allow []string, err error)
 	HeadGet(w http.ResponseWriter, r *http.Request) error
 	Propfind(r *http.Request, pf *Propfind, depth Depth) (*Multistatus, error)
 	Proppatch(r *http.Request, pu *Propertyupdate) (*Response, error)
@@ -140,13 +140,14 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *Handler) handleOptions(w http.ResponseWriter, r *http.Request) error {
-	methods, err := h.Backend.Options(r)
+	caps, allow, err := h.Backend.Options(r)
 	if err != nil {
 		return err
 	}
+	caps = append([]string{"1", "3"}, caps...)
 
-	w.Header().Add("Allow", strings.Join(methods, ", "))
+	w.Header().Add("DAV", strings.Join(caps, ", "))
-	w.Header().Add("DAV", "1, 3")
+	w.Header().Add("Allow", strings.Join(allow, ", "))
 	w.WriteHeader(http.StatusNoContent)
 	return nil
 }

server.go

@@ -45,31 +45,27 @@ type backend struct {
 	FileSystem FileSystem
 }
 
-func (b *backend) Options(r *http.Request) ([]string, error) {
+func (b *backend) Options(r *http.Request) (caps []string, allow []string, err error) {
 	fi, err := b.FileSystem.Stat(r.URL.Path)
 	if os.IsNotExist(err) {
-		return []string{http.MethodOptions}, nil
+		return nil, []string{http.MethodOptions, http.MethodPut, "MKCOL"}, nil
 	} else if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
-	if fi.IsDir {
+	allow = []string{
-		return []string{
+		http.MethodOptions,
-			http.MethodOptions,
+		http.MethodDelete,
-			http.MethodDelete,
+		"PROPFIND",
-			"PROPFIND",
+		"COPY",
-			"MKCOL",
+		"MOVE",
-		}, nil
-	} else {
-		return []string{
-			http.MethodOptions,
-			http.MethodHead,
-			http.MethodGet,
-			http.MethodPut,
-			http.MethodDelete,
-			"PROPFIND",
-		}, nil
 	}
+
+	if !fi.IsDir {
+		allow = append(allow, http.MethodHead, http.MethodGet, http.MethodPut)
+	}
+
+	return nil, allow, nil
 }
 
 func (b *backend) HeadGet(w http.ResponseWriter, r *http.Request) error {