update filebrowser expand contract and methods (#500)

src/Microsoft.SqlTools.ServiceLayer/FileBrowser/Contracts/FileBrowserExpandedNotification.cs

@@ -17,9 +17,14 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser.Contracts
         public string OwnerUri;
 
         /// <summary>
-        /// Expanded node 
+        /// Expand path
         /// </summary>
-        public FileTreeNode ExpandedNode;
+        public string ExpandPath;
+
+        /// <summary>
+        /// Children nodes
+        /// </summary>
+        public FileTreeNode[] Children;
 
         /// <summary>
         /// Result of the operation

src/Microsoft.SqlTools.ServiceLayer/FileBrowser/Contracts/FileTreeNode.cs

@@ -23,7 +23,7 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser.Contracts
         /// <summary>
         /// List of children nodes
         /// </summary>
-        public List<FileTreeNode> Children { get; private set; }
+        public List<FileTreeNode> Children { get; set; }
 
         // Indicates if the node is expanded, applicable to a folder.
         public bool IsExpanded { get; set; }

src/Microsoft.SqlTools.ServiceLayer/FileBrowser/FileBrowserOperation.cs

@@ -52,7 +52,7 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser
 
         #endregion
 
-        #region public properties and methods
+        #region public properties
 
         public FileTree FileTree
         {
@@ -70,6 +70,8 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser
             }
         }
 
+        #endregion
+
         public void PopulateFileTree()
         {
             this.PathSeparator = GetPathSeparator(this.Enumerator, this.sqlConnection);
@@ -107,7 +109,7 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser
                         currentNode.IsExpanded = true;
                         if (!currentNode.IsFile)
                         {
-                            PopulateFileNode(currentNode);
+                            currentNode.Children = this.GetChildren(currentNode.FullPath);
                         }
                         currentChildren = currentNode.Children;
                         lastNode = currentNode;
@@ -129,38 +131,10 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser
             }
         }
 
-        #endregion
+        public List<FileTreeNode> GetChildren(string filepath)
-
-        private void PopulateDrives()
         {
-            bool first = true;
+            List<FileTreeNode> children = new List<FileTreeNode>();
-            foreach (var fileInfo in EnumerateDrives(Enumerator, sqlConnection))
+            foreach (var file in EnumerateFilesInFolder(Enumerator, sqlConnection, filepath))
-            {
-                // Windows drive letter paths have a '\' at the end. Linux drive paths won't have a '\'.
-                var node = new FileTreeNode
-                {
-                    Name = Convert.ToString(fileInfo.path, CultureInfo.InvariantCulture).TrimEnd('\\'),
-                    FullPath = fileInfo.path
-                };
-
-                this.fileTree.RootNode.AddChildNode(node);
-
-                if (first)
-                {
-                    this.fileTree.SelectedNode = node;
-                    first = false;
-                }
-
-                PopulateFileNode(node);
-            }
-        }
-
-        private void PopulateFileNode(FileTreeNode parentNode)
-        {
-            string parentPath = parentNode.FullPath;
-            parentNode.Children.Clear();
-
-            foreach (var file in EnumerateFilesInFolder(Enumerator, sqlConnection, parentPath))
             {
                 bool isFile = !string.IsNullOrEmpty(file.fileName);
                 FileTreeNode treeNode = new FileTreeNode();
@@ -180,9 +154,35 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser
                 // add the node to the tree
                 if (!isFile || (this.FilterFile(treeNode.Name, this.fileFilters)))
                 {
-                    parentNode.AddChildNode(treeNode);
+                    children.Add(treeNode);
                 }
             }
+
+            return children;
+        }
+
+        public void PopulateDrives()
+        {
+            bool first = true;
+            foreach (var fileInfo in EnumerateDrives(Enumerator, sqlConnection))
+            {
+                // Windows drive letter paths have a '\' at the end. Linux drive paths won't have a '\'.
+                var node = new FileTreeNode
+                {
+                    Name = Convert.ToString(fileInfo.path, CultureInfo.InvariantCulture).TrimEnd('\\'),
+                    FullPath = fileInfo.path
+                };
+
+                this.fileTree.RootNode.AddChildNode(node);
+
+                if (first)
+                {
+                    this.fileTree.SelectedNode = node;
+                    first = false;
+                }
+
+                node.Children = this.GetChildren(node.FullPath);
+            }
         }
 
         /// <summary>

src/Microsoft.SqlTools.ServiceLayer/FileBrowser/FileBrowserService.cs

@@ -230,9 +230,9 @@ namespace Microsoft.SqlTools.ServiceLayer.FileBrowser
                 if (this.ownerToFileBrowserMap.ContainsKey(fileBrowserParams.OwnerUri))
                 {
                     FileBrowserOperation browser = this.ownerToFileBrowserMap[fileBrowserParams.OwnerUri];
-                    browser.ExpandSelectedNode(fileBrowserParams.ExpandPath);
+                    result.Children = browser.GetChildren(fileBrowserParams.ExpandPath).ToArray();
+                    result.ExpandPath = fileBrowserParams.ExpandPath;
                     result.OwnerUri = fileBrowserParams.OwnerUri;
-                    result.ExpandedNode = browser.FileTree.SelectedNode;
                     result.Succeeded = true;
                 }
                 else

test/Microsoft.SqlTools.ServiceLayer.IntegrationTests/DisasterRecovery/BackupServiceTests.cs

@@ -288,9 +288,8 @@ CREATE CERTIFICATE {1} WITH SUBJECT = 'Backup Encryption Certificate'; ";
             // Verify result
             serviceHostMock.Verify(x => x.SendEvent(FileBrowserExpandedNotification.Type,
                 It.Is<FileBrowserExpandedParams>(p => p.Succeeded == true
-                && p.ExpandedNode != null
+                && p.Children != null
-                && p.ExpandedNode.Children != null
+                && p.Children.Length > 0)),
-                && p.ExpandedNode.Children.Count > 0)),
                 Times.Once());
 
             var validateParams = new FileBrowserValidateParams