add exception handling when Windows Search service not available

Flow.Launcher.Test/Plugins/ExplorerTest.cs

@@ -116,7 +116,7 @@ namespace Flow.Launcher.Test.Plugins
         {
             // Given
             var queryConstructor = new QueryConstructor(new Settings());
-            var baseQuery = queryConstructor.BaseQueryHelper;
+            var baseQuery = queryConstructor.CreateBaseQuery();
 
             // system running this test could have different locale than the hard-coded 1033 LCID en-US.
             var queryKeywordLocale = baseQuery.QueryKeywordLocale;

Plugins/Flow.Launcher.Plugin.Explorer/Search/WindowsIndex/QueryConstructor.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Buffers;
 using Microsoft.Search.Interop;
 
@@ -6,25 +6,21 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
 {
     public class QueryConstructor
     {
-        private Settings Settings { get; }
+        private Settings settings { get; }
 
         private const string SystemIndex = "SystemIndex";
 
-        public CSearchQueryHelper BaseQueryHelper { get; }
-
         public QueryConstructor(Settings settings)
         {
-            Settings = settings;
+            this.settings = settings;
-            BaseQueryHelper = CreateBaseQuery();
         }
 
-
+        public CSearchQueryHelper CreateBaseQuery()
-        private CSearchQueryHelper CreateBaseQuery()
         {
             var baseQuery = CreateQueryHelper();
 
             // Set the number of results we want. Don't set this property if all results are needed.
-            baseQuery.QueryMaxResults = Settings.MaxResult;
+            baseQuery.QueryMaxResults = settings.MaxResult;
 
             // Set list of columns we want to display, getting the path presently
             baseQuery.QuerySelectColumns = "System.FileName, System.ItemUrl, System.ItemType";
@@ -38,9 +34,10 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
             return baseQuery;
         }
 
-        internal static CSearchQueryHelper CreateQueryHelper()
+        internal CSearchQueryHelper CreateQueryHelper()
         {
             // This uses the Microsoft.Search.Interop assembly
+            // Throws COMException if Windows Search service is not running/disabled, this needs to be caught
             var manager = new CSearchManager();
 
             // SystemIndex catalog is the default catalog in Windows
@@ -67,7 +64,7 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
                 ? RecursiveDirectoryConstraint(path)
                 : TopLevelDirectoryConstraint(path);
 
-            var query = $"SELECT TOP {Settings.MaxResult} {BaseQueryHelper.QuerySelectColumns} FROM {SystemIndex} WHERE {scopeConstraint} {queryConstraint} ORDER BY {FileName}";
+            var query = $"SELECT TOP {settings.MaxResult} {CreateBaseQuery().QuerySelectColumns} FROM {SystemIndex} WHERE {scopeConstraint} {queryConstraint} ORDER BY {FileName}";
 
             return query;
         }
@@ -81,7 +78,7 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
                 userSearchString = "*";
 
             // Generate SQL from constructed parameters, converting the userSearchString from AQS->WHERE clause
-            return $"{BaseQueryHelper.GenerateSQLFromUserQuery(userSearchString.ToString())} AND {RestrictionsForAllFilesAndFoldersSearch} ORDER BY {FileName}";
+            return $"{CreateBaseQuery().GenerateSQLFromUserQuery(userSearchString.ToString())} AND {RestrictionsForAllFilesAndFoldersSearch} ORDER BY {FileName}";
         }
 
         ///<summary>
@@ -101,7 +98,7 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
         public string FileContent(ReadOnlySpan<char> userSearchString)
         {
             string query =
-                $"SELECT TOP {Settings.MaxResult} {BaseQueryHelper.QuerySelectColumns} FROM {SystemIndex} WHERE {RestrictionsForFileContentSearch(userSearchString)} AND {RestrictionsForAllFilesAndFoldersSearch} ORDER BY {FileName}";
+                $"SELECT TOP {settings.MaxResult} {CreateBaseQuery().QuerySelectColumns} FROM {SystemIndex} WHERE {RestrictionsForFileContentSearch(userSearchString)} AND {RestrictionsForAllFilesAndFoldersSearch} ORDER BY {FileName}";
 
             return query;
         }

Plugins/Flow.Launcher.Plugin.Explorer/Search/WindowsIndex/WindowsIndex.cs

@@ -1,4 +1,4 @@
-using Flow.Launcher.Infrastructure.Logger;
+using Flow.Launcher.Infrastructure.Logger;
 using Microsoft.Search.Interop;
 using System;
 using System.Collections.Generic;
@@ -86,32 +86,6 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
             {
                 throw new SearchException("Windows Index", e.Message, e);
             }
-            catch (COMException)
-            {
-                // Occurs because the Windows Indexing (WSearch) is turned off in services and unable to be used by Explorer plugin
-                
-                if (!SearchManager.Settings.WarnWindowsSearchServiceOff)
-                    return AsyncEnumerable.Empty<SearchResult>();
-
-                var api = SearchManager.Context.API;
-
-                throw new EngineNotAvailableException(
-                    "Windows Index",
-                    api.GetTranslation("plugin_explorer_windowsSearchServiceFix"),
-                    api.GetTranslation("plugin_explorer_windowsSearchServiceNotRunning"),
-                    c =>
-                    {
-                        SearchManager.Settings.WarnWindowsSearchServiceOff = false;
-
-                        // Clears the warning message so user is not mistaken that it has not worked
-                        api.ChangeQuery(string.Empty);
-
-                        return ValueTask.FromResult(false);
-                    })
-                {
-                    ErrorIcon = Constants.WindowsIndexErrorImagePath
-                };
-            }
         }
 
         internal static bool PathIsIndexed(string path)

Plugins/Flow.Launcher.Plugin.Explorer/Search/WindowsIndex/WindowsIndexSearchManager.cs

@@ -1,24 +1,24 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
+using Flow.Launcher.Plugin.Explorer.Exceptions;
 using Flow.Launcher.Plugin.Explorer.Search.IProvider;
-using Microsoft.Search.Interop;
 
 namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
 {
     public class WindowsIndexSearchManager : IIndexProvider, IContentIndexProvider, IPathIndexProvider
     {
         private Settings Settings { get; }
-        private QueryConstructor QueryConstructor { get; }
 
-        private CSearchQueryHelper QueryHelper { get; }
+        private QueryConstructor QueryConstructor { get; }
+        
         public WindowsIndexSearchManager(Settings settings)
         {
             Settings = settings;
             QueryConstructor = new QueryConstructor(Settings);
-            QueryHelper = QueryConstructor.CreateQueryHelper();
         }
 
         private IAsyncEnumerable<SearchResult> WindowsIndexFileContentSearchAsync(
@@ -28,20 +28,38 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
             if (querySearchString.IsEmpty)
                 return AsyncEnumerable.Empty<SearchResult>();
 
-            return WindowsIndex.WindowsIndexSearchAsync(
+            try
-                QueryHelper.ConnectionString,
+            {
-                QueryConstructor.FileContent(querySearchString),
+                return WindowsIndex.WindowsIndexSearchAsync(
-                token);
+                    QueryConstructor.CreateQueryHelper().ConnectionString,
+                    QueryConstructor.FileContent(querySearchString),
+                    token);
+            }
+            catch (COMException)
+            {
+                // Occurs when the Windows Indexing (WSearch) is turned off in services and unable to be used by Explorer plugin
+                // Thrown by QueryConstructor.CreateQueryHelper()
+                return HandledEngineNotAvailableExceptionAsync();
+            }
         }
 
         private IAsyncEnumerable<SearchResult> WindowsIndexFilesAndFoldersSearchAsync(
             ReadOnlySpan<char> querySearchString,
             CancellationToken token = default)
         {
-            return WindowsIndex.WindowsIndexSearchAsync(
+            try
-                QueryHelper.ConnectionString,
+            {
-                QueryConstructor.FilesAndFolders(querySearchString),
+                return WindowsIndex.WindowsIndexSearchAsync(
-                token);
+                    QueryConstructor.CreateQueryHelper().ConnectionString,
+                    QueryConstructor.FilesAndFolders(querySearchString),
+                    token);
+            }
+            catch (COMException)
+            {
+                // Occurs when the Windows Indexing (WSearch) is turned off in services and unable to be used by Explorer plugin
+                // Thrown by QueryConstructor.CreateQueryHelper()
+                return HandledEngineNotAvailableExceptionAsync();
+            }
         }
 
         private IAsyncEnumerable<SearchResult> WindowsIndexTopLevelFolderSearchAsync(
@@ -50,12 +68,19 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
             bool recursive,
             CancellationToken token)
         {
-            var queryConstructor = new QueryConstructor(Settings);
+            try
-
+            {
-            return WindowsIndex.WindowsIndexSearchAsync(
+                return WindowsIndex.WindowsIndexSearchAsync(
-                QueryConstructor.CreateQueryHelper().ConnectionString,
+                    QueryConstructor.CreateQueryHelper().ConnectionString,
-                queryConstructor.Directory(path, search, recursive),
+                    QueryConstructor.Directory(path, search, recursive),
-                token);
+                    token);
+            }
+            catch (COMException)
+            {
+                // Occurs when the Windows Indexing (WSearch) is turned off in services and unable to be used by Explorer plugin
+                // Thrown by QueryConstructor.CreateQueryHelper()
+                return HandledEngineNotAvailableExceptionAsync();
+            }
         }
         public IAsyncEnumerable<SearchResult> SearchAsync(string search, CancellationToken token)
         {
@@ -69,5 +94,30 @@ namespace Flow.Launcher.Plugin.Explorer.Search.WindowsIndex
         {
             return WindowsIndexTopLevelFolderSearchAsync(search, path, recursive, token);
         }
+
+        private IAsyncEnumerable<SearchResult> HandledEngineNotAvailableExceptionAsync()
+        {
+            if (!SearchManager.Settings.WarnWindowsSearchServiceOff)
+                return AsyncEnumerable.Empty<SearchResult>();
+
+            var api = SearchManager.Context.API;
+
+            throw new EngineNotAvailableException(
+                "Windows Index",
+                api.GetTranslation("plugin_explorer_windowsSearchServiceFix"),
+                api.GetTranslation("plugin_explorer_windowsSearchServiceNotRunning"),
+                c =>
+                {
+                    SearchManager.Settings.WarnWindowsSearchServiceOff = false;
+
+                    // Clears the warning message so user is not mistaken that it has not worked
+                    api.ChangeQuery(string.Empty);
+
+                    return ValueTask.FromResult(false);
+                })
+            {
+                ErrorIcon = Constants.WindowsIndexErrorImagePath
+            };
+        }
     }
 }