private void OnFileChanged()

in src/WebJobs.Script.WebHost/FileMonitoringService.cs [266:323]
40 lines of code
11 McCabe index (conditional complexity)

        private void OnFileChanged(FileSystemEventArgs e)
        {
            // We will perform a host restart in the following cases:
            // - the file change was under one of the configured watched directories (e.g. node_modules, shared code directories, etc.)
            // - the host.json file was changed
            // - a function.json file was changed
            // - a proxies.json file was changed
            // - a function directory was added/removed/renamed
            // A full host shutdown is performed when an assembly (.dll, .exe) in a watched directory is modified

            string changeDescription = string.Empty;
            string directory = GetRelativeDirectory(e.FullPath, _scriptOptions.RootScriptPath);
            string fileName = Path.GetFileName(e.Name);
            bool shutdown = false;

            if (_scriptOptions.WatchDirectories.Contains(directory))
            {
                changeDescription = "Watched directory";
            }
            else if (string.Equals(fileName, ScriptConstants.AppOfflineFileName, StringComparison.OrdinalIgnoreCase))
            {
                // app_offline.htm has changed
                // when app_offline.htm is created, we trigger
                // a shutdown right away so when the host
                // starts back up it will be offline
                // when app_offline.htm is deleted, we trigger
                // a restart to bring the host back online
                changeDescription = "File";
                if (File.Exists(e.FullPath))
                {
                    TraceFileChangeRestart(changeDescription, e.ChangeType.ToString(), e.FullPath, isShutdown: true);
                    Shutdown();
                }
            }
            else if (_scriptOptions.WatchFiles.Any(f => string.Equals(fileName, f, StringComparison.OrdinalIgnoreCase)))
            {
                changeDescription = "File";
            }
            else if ((e.ChangeType == WatcherChangeTypes.Deleted || Directory.Exists(e.FullPath))
                && !_rootDirectorySnapshot.SequenceEqual(Directory.EnumerateDirectories(_scriptOptions.RootScriptPath)))
            {
                // Check directory snapshot only if "Deleted" change or if directory changed
                changeDescription = "Directory";
            }

            if (!string.IsNullOrEmpty(changeDescription))
            {
                string fileExtension = Path.GetExtension(fileName);
                if (!string.IsNullOrEmpty(fileExtension) && ScriptConstants.AssemblyFileTypes.Contains(fileExtension, StringComparer.OrdinalIgnoreCase))
                {
                    shutdown = true;
                }

                TraceFileChangeRestart(changeDescription, e.ChangeType.ToString(), e.FullPath, shutdown);
                ScheduleRestartAsync(shutdown).ContinueWith(t => _logger.LogError(t.Exception, $"Error restarting host (full shutdown: {shutdown})"),
                    TaskContinuationOptions.ExecuteSynchronously | TaskContinuationOptions.OnlyOnFaulted);
            }
        }