Allow settings paramter to take preset value

Currently, we can provide either a PowerShell data file or a
hashtable to the settings parameter. But we would like users to
take advantage of the builtin setting files {PSGallery,DSC,etc}
by providing only their names as values. This provides a easier
way to use these builtin setting files.

Author: Kapil Borle

Engine/Commands/InvokeScriptAnalyzerCommand.cs

@@ -278,6 +278,13 @@ protected override void BeginProcessing()
                             path));
                 }
             }
+            else if (IsBuiltinSettingPreset(settings))
+            {
+                settingFileHasErrors = !ScriptAnalyzer.Instance.ParseProfile(
+                    Helper.GetSettingPresetFilePath(settings as string),
+                    this.SessionState.Path,
+                    this);
+            }
             else
             {
                 settingFileHasErrors = !ScriptAnalyzer.Instance.ParseProfile(this.settings, this.SessionState.Path, this);
@@ -348,7 +355,19 @@ protected override void StopProcessing()
 
 #endregion
 
-#region Methods
+#region Private Methods
+
+        private static bool IsBuiltinSettingPreset(object settingPreset)
+        {
+            var preset = settingPreset as string;
+            if (preset != null)
+            {
+                return Helper.GetBuiltinSettingPresets().Contains(preset, StringComparer.OrdinalIgnoreCase);
+            }
+
+            return false;
+        }
+
         private void ProcessInput()
         {
             IEnumerable<DiagnosticRecord> diagnosticsList = Enumerable.Empty<DiagnosticRecord>();
@@ -392,6 +411,6 @@ private bool IsFileParameterSet()
         {
             return String.Equals(this.ParameterSetName, "File", StringComparison.OrdinalIgnoreCase);
         }
-#endregion
+#endregion // Private Methods
     }
 }

Engine/Helper.cs

@@ -201,6 +201,42 @@ public static string GetShippedSettingsDirectory()
             return settingsPath;
         }
 
+        /// <summary>
+        /// Returns the builtin setting presets
+        ///
+        /// Looks for powershell data files (*.psd1) in the PSScriptAnalyzer module settings directory
+        /// and returns the names of the files without extension
+        /// </summary>
+        internal static IEnumerable<string> GetBuiltinSettingPresets()
+        {
+            var settingsPath = GetShippedSettingsDirectory();
+            if (settingsPath != null)
+            {
+                foreach (var filepath in System.IO.Directory.EnumerateFiles(settingsPath, "*.psd1"))
+                {
+                    yield return System.IO.Path.GetFileNameWithoutExtension(filepath);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Gets the path to the settings file corresponding to the given preset.
+        ///
+        /// If the corresponding preset file is not found, the method returns null.
+        /// </summary>
+        internal static string GetSettingPresetFilePath(string settingPreset)
+        {
+            var settingsPath = GetShippedSettingsDirectory();
+            if (settingsPath != null)
+            {
+                if (GetBuiltinSettingPresets().Contains(settingPreset, StringComparer.OrdinalIgnoreCase))
+                {
+                    return System.IO.Path.Combine(settingsPath, settingPreset + ".psd1");
+                }
+            }
+
+            return null;
+        }
 
         /// <summary>
         /// Returns all the rule arguments