Handle no avatar, add delete avatar support

backend/internal/rest/handler_profile.go

@@ -20,7 +20,7 @@ type updatePasswordRequest struct {
 
 func (h *Handler) getProfile(w http.ResponseWriter, r *http.Request) {
 	u := userFromRequest(r)
-	writeJson(w, http.StatusOK, newUserResponse(u))
+	h.respondUser(w, r, u, http.StatusOK)
 }
 
 func (h *Handler) updateProfile(w http.ResponseWriter, r *http.Request) {
@@ -58,7 +58,7 @@ func (h *Handler) updateProfile(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	writeJson(w, http.StatusOK, newUserResponse(updated))
+	h.respondUser(w, r, updated, http.StatusOK)
 }
 
 func (h *Handler) updatePassword(w http.ResponseWriter, r *http.Request) {
@@ -109,6 +109,19 @@ func (h *Handler) uploadAvatar(w http.ResponseWriter, r *http.Request) {
 	writeNoContent(w)
 }
 
+// deleteAvatar removes the caller's avatar. It is idempotent: deleting an
+// avatar that does not exist still succeeds.
+func (h *Handler) deleteAvatar(w http.ResponseWriter, r *http.Request) {
+	u := userFromRequest(r)
+
+	if err := h.users.DeleteAvatar(r.Context(), u); err != nil {
+		h.fail(w, err)
+		return
+	}
+
+	writeNoContent(w)
+}
+
 func (h *Handler) getAvatar(w http.ResponseWriter, r *http.Request) {
 	u := userFromRequest(r)