Added directory/file exists

src/index.js

@@ -13,6 +13,17 @@ export const create_api = (conn) => {
   return {
     directory: {
       create: async (remote_path) => ops.create_directory(conn, remote_path),
+      exists: async (remote_path) => {
+        try {
+          const info = await ops.get_file_attributes2(conn, remote_path);
+          return info.directory;
+        } catch (e) {
+          if (e.message.split(':')[1].trim() == '-2') {
+            return false;
+          }
+          throw new Error(e.message);
+        }
+      },
       list: async (remote_path, page_reader_cb) =>
         ops.list_directory(conn, remote_path, page_reader_cb),
       remove: async (remote_path) => ops.remove_directory(conn, remote_path),
@@ -43,6 +54,17 @@ export const create_api = (conn) => {
           overwrite,
           resume
         ),
+      exists: async (remote_path) => {
+        try {
+          const info = await ops.get_file_attributes2(conn, remote_path);
+          return !info.directory;
+        } catch (e) {
+          if (e.message.split(':')[1].trim() == '-2') {
+            return false;
+          }
+          throw new Error(e.message);
+        }
+      },
       open: async (remote_path) =>
         new file(conn, await ops.open_file(conn, remote_path), remote_path),
       upload: async (local_path, remote_path, progress_cb, overwrite, resume) =>