Some exceptions have been added.

Author: VLAD

FastSearchLibrary/DirectorySearcher/DirectorySearcherMultiple.cs

@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -75,9 +73,8 @@ protected virtual void OnSearchCompleted(bool isCanceled)
             /// <exception cref="ArgumentException"></exception>
             /// <exception cref="ArgumentNullException"></exception>
             public DirectorySearcherMultiple(List<string> folders, Func<DirectoryInfo, bool> isValid, CancellationTokenSource tokenSource, ExecuteHandlers handlerOption, bool suppressOperationCanceledException)
-            { 
-                 foreach (var folder in folders)
-                     CheckFolder(folder);
+            {
+                 CheckFolders(folders);
 
                  CheckDelegate(isValid);
 
@@ -142,9 +139,7 @@ public DirectorySearcherMultiple(List<string> folders, Func<DirectoryInfo, bool>
             /// <exception cref="ArgumentNullException"></exception>
             public DirectorySearcherMultiple(List<string> folders, string pattern, CancellationTokenSource tokenSource, ExecuteHandlers handlerOption, bool suppressOperationCanceledException)
             {
-
-                foreach (var folder in folders)
-                    CheckFolder(folder);
+                CheckFolders(folders);
 
                 CheckPattern(pattern);
 
@@ -209,6 +204,19 @@ public DirectorySearcherMultiple(List<string> folders, CancellationTokenSource t
 
 
             #region Checking methods
+            
+            private void CheckFolders(List<string> folders)
+            {
+                if (folders == null)
+                    throw new ArgumentNullException(nameof(folders), "Argument is null.");
+
+                if (folders.Count == 0)
+                    throw new ArgumentException("Argument is an empty list.", nameof(folders));
+
+                foreach (var folder in folders)
+                    CheckFolder(folder);
+            }
+
 
             private void CheckFolder(string folder)
             {

FastSearchLibrary/FastSearchLibrary.csproj

@@ -15,7 +15,7 @@
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
     <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
+    <Optimize>true</Optimize>
     <OutputPath>bin\Debug\</OutputPath>
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>

FastSearchLibrary/FileSearcher/FileSearcherMultiple.cs

@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -74,9 +72,8 @@ protected virtual void OnSearchCompleted(bool isCanceled)
         /// <exception cref="ArgumentException"></exception>
         /// <exception cref="ArgumentNullException"></exception>
         public FileSearcherMultiple(List<string> folders, Func<FileInfo, bool> isValid, CancellationTokenSource tokenSource, ExecuteHandlers handlerOption, bool suppressOperationCanceledException)
-        { 
-            foreach (var folder in folders)
-                CheckFolder(folder);
+        {
+            CheckFolders(folders);
 
             CheckDelegate(isValid);
 
@@ -140,9 +137,7 @@ public FileSearcherMultiple(List<string> folders, Func<FileInfo, bool> isValid,
         /// <exception cref="ArgumentNullException"></exception>
         public FileSearcherMultiple(List<string> folders, string pattern, CancellationTokenSource tokenSource, ExecuteHandlers handlerOption, bool suppressOperationCanceledException)
         {
-
-            foreach (var folder in folders)
-                CheckFolder(folder);
+            CheckFolders(folders);
 
             CheckPattern(pattern);
 
@@ -206,6 +201,18 @@ public FileSearcherMultiple(List<string> folders, CancellationTokenSource tokenS
 
 
         #region Checking methods
+        private void CheckFolders(List<string> folders)
+        {
+            if (folders == null)
+                throw new ArgumentNullException(nameof(folders), "Argument is null.");
+
+            if (folders.Count == 0)
+                throw new ArgumentException("Argument is an empty list.", nameof(folders));
+
+            foreach (var folder in folders)
+                CheckFolder(folder);
+        }
+
 
         private void CheckFolder(string folder)
         {

FastSearchLibrary/Properties/AssemblyInfo.cs

@@ -1,5 +1,4 @@
 using System.Reflection;
-using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 // General Information about an assembly is controlled through the following 
@@ -32,5 +31,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.1.6.0")]
-[assembly: AssemblyFileVersion("1.1.6.0")]
+[assembly: AssemblyVersion("1.1.6.1")]
+[assembly: AssemblyFileVersion("1.1.6.1")]