Refactored the code to make it unit testable

src/modules/launcher/Plugins/Wox.Plugin.Indexer/SearchHelper/WindowsSearchAPI.cs

@@ -7,7 +7,63 @@ namespace Wox.Plugin.Indexer.SearchHelper
 {
     public class WindowsSearchAPI
     {
-        public IEnumerable<SearchResult> Search(string keyword, string pattern = "*", int offset = 0, int maxCount = 100)
+        private OleDbConnection conn;
+        private OleDbCommand command;
+        private OleDbDataReader WDSResults;
+
+        public IEnumerable<SearchResult> ExecuteQuery(ISearchQueryHelper queryHelper, string keyword)
+        {
+            // Generate SQL from our parameters, converting the userQuery from AQS->WHERE clause
+            string sqlQuery = queryHelper.GenerateSQLFromUserQuery(keyword);
+
+            // --- Perform the query ---
+            // create an OleDbConnection object which connects to the indexer provider with the windows application
+            using (conn = new OleDbConnection(queryHelper.ConnectionString))
+            {
+                // open the connection
+                conn.Open();
+
+                // now create an OleDB command object with the query we built above and the connection we just opened.
+                using (command = new OleDbCommand(sqlQuery, conn))
+                {
+                    // execute the command, which returns the results as an OleDbDataReader.
+                    using (WDSResults = command.ExecuteReader())
+                    {
+                        while (WDSResults.Read())
+                        {
+                            // col 0 is our path in display format
+                            Console.WriteLine("{0}", WDSResults.GetString(0));
+                            var result = new SearchResult { Path = WDSResults.GetString(0) };
+
+                            yield return result;
+                        }
+                    }
+
+                }
+            }
+        }
+
+        public void setQueryHelper(ref ISearchQueryHelper queryHelper, string pattern)
+        {
+            // convert file pattern if it is not '*'. Don't create restriction for '*' as it includes all files.
+            if (pattern != "*")
+            {
+                pattern = pattern.Replace("*", "%");
+                pattern = pattern.Replace("?", "_");
+
+                if (pattern.Contains("%") || pattern.Contains("_"))
+                {
+                    queryHelper.QueryWhereRestrictions += " AND System.FileName LIKE '" + pattern + "' ";
+                }
+                else
+                {
+                    // if there are no wildcards we can use a contains which is much faster as it uses the index
+                    queryHelper.QueryWhereRestrictions += " AND Contains(System.FileName, '" + pattern + "') ";
+                }
+            }
+        }
+
+        public IEnumerable<SearchResult> Search(string keyword, string pattern = "*", int maxCount = 100)
         {
             // This uses the Microsoft.Search.Interop assembly
             CSearchManager manager = new CSearchManager();
@@ -27,55 +83,12 @@ namespace Wox.Plugin.Indexer.SearchHelper
             // Set additional query restriction
             queryHelper.QueryWhereRestrictions = "AND scope='file:'";
 
-            // convert file pattern if it is not '*'. Don't create restriction for '*' as it includes all files.
-            if (pattern != "*")
-            {
-                pattern = pattern.Replace("*", "%");
-                pattern = pattern.Replace("?", "_");
-
-                if (pattern.Contains("%") || pattern.Contains("_"))
-                {
-                    queryHelper.QueryWhereRestrictions += " AND System.FileName LIKE '" + pattern + "' ";
-                }
-                else
-                {
-                    // if there are no wildcards we can use a contains which is much faster as it uses the index
-                    queryHelper.QueryWhereRestrictions += " AND Contains(System.FileName, '" + pattern + "') ";
-                }
-            }
-
             // Set sorting order 
             queryHelper.QuerySorting = "System.DateModified DESC";
 
-            // Generate SQL from our parameters, converting the userQuery from AQS->WHERE clause
+            setQueryHelper(ref queryHelper, pattern);
-            string sqlQuery = queryHelper.GenerateSQLFromUserQuery(keyword);
-
-            // --- Perform the query ---
-            // create an OleDbConnection object which connects to the indexer provider with the windows application
-            using (System.Data.OleDb.OleDbConnection conn = new OleDbConnection(queryHelper.ConnectionString))
-            {
-                // open the connection
-                conn.Open();
-
-                // now create an OleDB command object with the query we built above and the connection we just opened.
-                using (OleDbCommand command = new OleDbCommand(sqlQuery, conn))
-                {
-                    // execute the command, which returns the results as an OleDbDataReader.
-                    using (OleDbDataReader WDSResults = command.ExecuteReader())
-                    {
-                        while (WDSResults.Read())
-                        {
-                            // col 0 is our path in display format
-                            Console.WriteLine("{0}", WDSResults.GetString(0));
-                            var result = new SearchResult { Path = WDSResults.GetString(0) };
-
-                            yield return result;
-                        }
-                    }
-
-                }
-            }
 
+            return ExecuteQuery(queryHelper, keyword);
         }
     }
 }