Add VFS capabilities method

Author: mahsa shadi

__tests__/adapters/vfs/system.js

@@ -35,6 +35,15 @@ describe('VFS System adapter', () => {
 
   const request = (name, ...args) => adapter[name](vfs, vfs)(...args);
 
+  test('#capabilities', () => {
+    return expect(request('capabilities', '', createOptions()))
+      .resolves
+      .toMatchObject({
+        pagination: false,
+        sort: false,
+      });
+  });
+
   test('#touch', () => {
     return expect(request('touch', 'home:/test', createOptions()))
       .resolves

src/adapters/vfs/system.js

@@ -162,6 +162,17 @@ module.exports = (core) => {
 
       return watch;
     },
+    /**
+     * Get filesystem capabilities
+     * @param {String} file The file path from client
+     * @param {Object} [options={}] Options
+     * @return {Object[]}
+     */
+    capabilities: vfs => (file, options = {}) =>
+      Promise.resolve({
+        sort:false,
+        pagination:false
+      }),
 
     /**
      * Checks if file exists

src/vfs.js

@@ -235,6 +235,7 @@ const vfs = core => {
 
   // Wire up all available VFS events
   return {
+    capabilities: createRequest(requestPath, 'capabilities', false),
     realpath: createRequest(requestPath, 'realpath', false),
     exists: createRequest(requestPath, 'exists', false, respondBoolean),
     stat: createRequest(requestPath, 'stat', false),
@@ -266,6 +267,7 @@ module.exports = core => {
   router.use(middleware);
 
   // Then all VFS routes (needs implementation above)
+  router.get('/capabilities', wrapper(methods.capabilities));
   router.get('/exists', wrapper(methods.exists));
   router.get('/stat', wrapper(methods.stat));
   router.get('/readdir', wrapper(methods.readdir));