Feature/delete peek scripts (#174)

* Delete temp script folder

* Delete folder and refactor code

* Add unit tests

* create folder per workspace

* Refactor and move creation to FileUtils

* Separate multiple assignment

src/Microsoft.SqlTools.ServiceLayer/LanguageServices/LanguageService.cs

@@ -21,6 +21,7 @@ using Microsoft.SqlTools.ServiceLayer.Hosting.Protocol;
 using Microsoft.SqlTools.ServiceLayer.LanguageServices.Completion;
 using Microsoft.SqlTools.ServiceLayer.LanguageServices.Contracts;
 using Microsoft.SqlTools.ServiceLayer.SqlContext;
+using Microsoft.SqlTools.ServiceLayer.QueryExecution;
 using Microsoft.SqlTools.ServiceLayer.Utility;
 using Microsoft.SqlTools.ServiceLayer.Workspace;
 using Microsoft.SqlTools.ServiceLayer.Workspace.Contracts;
@@ -216,6 +217,7 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
             serviceHost.RegisterShutdownTask(async (shutdownParams, shutdownRequestContext) =>
             {
                 Logger.Write(LogLevel.Verbose, "Shutting down language service");
+                DeletePeekDefinitionScripts();
                 await Task.FromResult(0);
             });
 
@@ -1232,5 +1234,14 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
                 return false;
             }
         }
+
+        internal void DeletePeekDefinitionScripts()
+        {
+            // Delete temp folder created to store peek definition scripts
+            if (FileUtils.SafeDirectoryExists(FileUtils.PeekDefinitionTempFolder))
+            {
+                FileUtils.SafeDirectoryDelete(FileUtils.PeekDefinitionTempFolder, true);
+            }
+        }
     }
 }

src/Microsoft.SqlTools.ServiceLayer/LanguageServices/PeekDefinition.cs

@@ -10,8 +10,9 @@ using System.Data.SqlClient;
 using Microsoft.SqlServer.Management.Smo;
 using Microsoft.SqlServer.Management.Common;
 using Microsoft.SqlServer.Management.SqlParser.Intellisense;
-using Microsoft.SqlTools.ServiceLayer.Utility;
 using Microsoft.SqlTools.ServiceLayer.Connection;
+using Microsoft.SqlTools.ServiceLayer.QueryExecution;
+using Microsoft.SqlTools.ServiceLayer.Utility;
 using Microsoft.SqlTools.ServiceLayer.Hosting.Protocol;
 using Microsoft.SqlTools.ServiceLayer.Workspace.Contracts;
 
@@ -47,9 +48,7 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
         {
             this.serverConnection = serverConnection;
             this.connectionInfo = connInfo;
-
-            DirectoryInfo tempScriptDirectory = Directory.CreateDirectory(Path.GetTempPath() + "mssql_definition");
-            this.tempPath = tempScriptDirectory.FullName;
+            this.tempPath = FileUtils.GetPeekDefinitionTempFolder();    
             Initialize();
         }
 

src/Microsoft.SqlTools.ServiceLayer/Utility/FileUtils.cs

@@ -8,6 +8,46 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
 {
     internal static class FileUtils
     {
+        internal static string PeekDefinitionTempFolder = Path.GetTempPath() + "mssql_definition"; 
+        internal static bool PeekDefinitionTempFolderCreated = false;
+
+        internal static string GetPeekDefinitionTempFolder()
+        {
+            string tempPath;
+            if (!PeekDefinitionTempFolderCreated)
+            {               
+                try
+                {
+                    // create new temp folder
+                    string tempFolder = string.Format("{0}_{1}", FileUtils.PeekDefinitionTempFolder, DateTime.Now.ToString("yyyyMMddHHmmssffff"));
+                    DirectoryInfo tempScriptDirectory = Directory.CreateDirectory(tempFolder);
+                    FileUtils.PeekDefinitionTempFolder = tempScriptDirectory.FullName;
+                    tempPath = tempScriptDirectory.FullName;
+                    PeekDefinitionTempFolderCreated = true;
+                }
+                catch (Exception)
+                {
+                    // swallow exception and use temp folder to store scripts
+                    tempPath = Path.GetTempPath();
+                }
+            }
+            else
+            {
+                try
+                {
+                    // use tempDirectory name created previously
+                    DirectoryInfo tempScriptDirectory = Directory.CreateDirectory(FileUtils.PeekDefinitionTempFolder);
+                    tempPath = tempScriptDirectory.FullName;
+                }
+                catch (Exception)
+                {
+                    // swallow exception and use temp folder to store scripts
+                    tempPath = Path.GetTempPath();
+                }
+            }
+            return tempPath;
+        }
+
         /// <summary>
         /// Checks if file exists and swallows exceptions, if any
         /// </summary>
@@ -42,5 +82,40 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
             }
         }
 
+        /// <summary>
+        /// Checks if file exists and swallows exceptions, if any
+        /// </summary>
+        /// <param name="path"> path of the file</param>
+        /// <returns></returns>
+        internal static bool SafeDirectoryExists(string path)
+        {
+            try
+            {
+                return Directory.Exists(path);
+            }
+            catch (Exception)
+            {
+                // Swallow exception
+                return false;
+            }
+        }
+
+
+        /// <summary>
+        /// Deletes a directory and swallows exceptions, if any
+        /// </summary>
+        /// <param name="path"></param>
+        internal static void SafeDirectoryDelete(string path, bool recursive)
+        {
+            try
+            {
+                Directory.Delete(path, recursive);
+            }
+            catch (Exception)
+            {
+                // Swallow exception, do nothing
+            }
+        }
+
     }
 }

src/Microsoft.SqlTools.ServiceLayer/Utility/TextUtilities.cs

@@ -6,7 +6,7 @@
 namespace Microsoft.SqlTools.ServiceLayer.Utility
 {
     public static class TextUtilities
-    {       
+    {   
         /// <summary>
         /// Find the position of the cursor in the SQL script content buffer and return previous new line position
         /// </summary>

test/Microsoft.SqlTools.ServiceLayer.Test/LanguageServer/PeekDefinitionTests.cs

@@ -19,6 +19,7 @@ using Microsoft.SqlTools.ServiceLayer.Hosting.Protocol.Contracts;
 using Microsoft.SqlTools.ServiceLayer.LanguageServices;
 using Microsoft.SqlTools.ServiceLayer.LanguageServices.Contracts;
 using Microsoft.SqlTools.ServiceLayer.SqlContext;
+using Microsoft.SqlTools.ServiceLayer.QueryExecution;
 using Microsoft.SqlTools.ServiceLayer.Test.QueryExecution;
 using Microsoft.SqlTools.ServiceLayer.Workspace;
 using Microsoft.SqlTools.ServiceLayer.Workspace.Contracts;
@@ -194,6 +195,33 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.LanguageServices
             Assert.Equal(actualSchemaName, expectedSchemaName);
         }
 
+        /// <summary>
+        /// Test Deletion of peek definition scripts for a valid temp folder that exists
+        /// </summary>
+        [Fact]
+        public void DeletePeekDefinitionScriptsTest()
+        {
+            PeekDefinition peekDefinition = new PeekDefinition(null, null);
+            var languageService = LanguageService.Instance;
+            Assert.True(Directory.Exists(FileUtils.PeekDefinitionTempFolder));
+            languageService.DeletePeekDefinitionScripts();
+            Assert.False(Directory.Exists(FileUtils.PeekDefinitionTempFolder));
+        }
+
+        /// <summary>
+        /// Test Deletion of peek definition scripts for a temp folder that does not exist
+        /// </summary>
+        [Fact]
+        public void DeletePeekDefinitionScriptsWhenFolderDoesNotExistTest()
+        {
+            var languageService = LanguageService.Instance;
+            PeekDefinition peekDefinition = new PeekDefinition(null, null);
+            FileUtils.SafeDirectoryDelete(FileUtils.PeekDefinitionTempFolder, true);
+            Assert.False(Directory.Exists(FileUtils.PeekDefinitionTempFolder));
+            // Expected not to throw any exception
+            languageService.DeletePeekDefinitionScripts();        
+        }
+         
 #if LIVE_CONNECTION_TESTS
         /// <summary>
         /// Test get definition for a table object with active connection