Extract code to modify rule sets

Extract the code to modify rule sets to a helper type.

src/VisualStudio/Core/SolutionExplorerShim/DiagnosticItem/DiagnosticItem.cs

@@ -148,102 +148,9 @@ private void UpdateRuleSetFile(string pathToRuleSet, ReportDiagnostic value)
         {
             var ruleSetDocument = XDocument.Load(pathToRuleSet);
 
-            var newAction = ConvertReportDiagnosticToAction(value);
-
-            var analyzerID = _analyzerItem.AnalyzerReference.Display;
-            var rules = FindOrCreateRulesElement(ruleSetDocument, analyzerID);
-            var rule = FindOrCreateRuleElement(rules, _descriptor.Id);
-
-            if (value == ReportDiagnostic.Default)
-            {
-                // If the new severity is 'Default' we just delete the entry for the rule from the ruleset file.
-                // In the absence of an explicit entry in the ruleset file, the rule reverts back to its 'Default'
-                // severity (so far as the 'current' ruleset file is concerened - the rule's effective severity
-                // could still be decided by other factors such as project settings or a base ruleset file).
-                rule.Remove();
-            }
-            else
-            {
-                rule.Attribute("Action").Value = newAction;
-            }
-
-            var allMatchingRules = ruleSetDocument.Root
-                                       .Descendants("Rule")
-                                       .Where(r => r.Attribute("Id").Value.Equals(_descriptor.Id))
-                                       .ToList();
-
-            foreach (var matchingRule in allMatchingRules)
-            {
-                if (value == ReportDiagnostic.Default)
-                {
-                    // If the new severity is 'Default' we just delete the entry for the rule from the ruleset file.
-                    // In the absence of an explicit entry in the ruleset file, the rule reverts back to its 'Default'
-                    // severity (so far as the 'current' ruleset file is concerened - the rule's effective severity
-                    // could still be decided by other factors such as project settings or a base ruleset file).
-                    matchingRule.Remove();
-                }
-                else
-                {
-                    matchingRule.Attribute("Action").Value = newAction;
-                }
-            }
+            ruleSetDocument.SetSeverity(_analyzerItem.AnalyzerReference.Display, _descriptor.Id, value);
 
             ruleSetDocument.Save(pathToRuleSet);
         }
-
-        private XElement FindOrCreateRuleElement(XElement rules, string id)
-        {
-            var ruleElement = rules
-                              .Elements("Rule")
-                              .FirstOrDefault(r => r.Attribute("Id").Value.Equals(id));
-
-            if (ruleElement == null)
-            {
-                ruleElement = new XElement("Rule",
-                                    new XAttribute("Id", id),
-                                    new XAttribute("Action", "Warning"));
-                rules.Add(ruleElement);
-            }
-
-            return ruleElement;
-        }
-
-        private XElement FindOrCreateRulesElement(XDocument ruleSetDocument, string analyzerID)
-        {
-            var rulesElement = ruleSetDocument.Root
-                               .Elements("Rules")
-                               .FirstOrDefault(r => r.Attribute("AnalyzerId").Value.Equals(analyzerID));
-
-            if (rulesElement == null)
-            {
-                rulesElement = new XElement("Rules",
-                                    new XAttribute("AnalyzerId", analyzerID),
-                                    new XAttribute("RuleNamespace", analyzerID));
-                ruleSetDocument.Root.Add(rulesElement);
-            }
-
-            return rulesElement;
-        }
-
-        private static string ConvertReportDiagnosticToAction(ReportDiagnostic value)
-        {
-            switch (value)
-            {
-                case ReportDiagnostic.Default:
-                    return "Default";
-                case ReportDiagnostic.Error:
-                    return "Error";
-                case ReportDiagnostic.Warn:
-                    return "Warning";
-                case ReportDiagnostic.Info:
-                    return "Info";
-                case ReportDiagnostic.Hidden:
-                    return "Hidden";
-                case ReportDiagnostic.Suppress:
-                    return "None";
-                default:
-                    throw ExceptionUtilities.Unreachable;
-            }
-        }
     }
 }

src/VisualStudio/Core/SolutionExplorerShim/RuleSetDocumentExtensions.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Linq;
+using System.Xml.Linq;
+using Microsoft.CodeAnalysis;
+using Roslyn.Utilities;
+
+namespace Microsoft.VisualStudio.LanguageServices.Implementation.SolutionExplorer
+{
+    internal static class RuleSetDocumentExtensions
+    {
+        internal static void SetSeverity(this XDocument ruleSet, string analyzerId, string ruleId, ReportDiagnostic value)
+        {
+            var newAction = ConvertReportDiagnosticToAction(value);
+
+            var rules = FindOrCreateRulesElement(ruleSet, analyzerId);
+            var rule = FindOrCreateRuleElement(rules, ruleId);
+
+            if (value == ReportDiagnostic.Default)
+            {
+                // If the new severity is 'Default' we just delete the entry for the rule from the ruleset file.
+                // In the absence of an explicit entry in the ruleset file, the rule reverts back to its 'Default'
+                // severity (so far as the 'current' ruleset file is concerened - the rule's effective severity
+                // could still be decided by other factors such as project settings or a base ruleset file).
+                rule.Remove();
+            }
+            else
+            {
+                rule.Attribute("Action").Value = newAction;
+            }
+
+            var allMatchingRules = ruleSet.Root
+                                       .Descendants("Rule")
+                                       .Where(r => r.Attribute("Id").Value.Equals(ruleId))
+                                       .ToList();
+
+            foreach (var matchingRule in allMatchingRules)
+            {
+                if (value == ReportDiagnostic.Default)
+                {
+                    // If the new severity is 'Default' we just delete the entry for the rule from the ruleset file.
+                    // In the absence of an explicit entry in the ruleset file, the rule reverts back to its 'Default'
+                    // severity (so far as the 'current' ruleset file is concerened - the rule's effective severity
+                    // could still be decided by other factors such as project settings or a base ruleset file).
+                    matchingRule.Remove();
+                }
+                else
+                {
+                    matchingRule.Attribute("Action").Value = newAction;
+                }
+            }
+        }
+
+        private static string ConvertReportDiagnosticToAction(ReportDiagnostic value)
+        {
+            switch (value)
+            {
+                case ReportDiagnostic.Default:
+                    return "Default";
+                case ReportDiagnostic.Error:
+                    return "Error";
+                case ReportDiagnostic.Warn:
+                    return "Warning";
+                case ReportDiagnostic.Info:
+                    return "Info";
+                case ReportDiagnostic.Hidden:
+                    return "Hidden";
+                case ReportDiagnostic.Suppress:
+                    return "None";
+                default:
+                    throw ExceptionUtilities.Unreachable;
+            }
+        }
+
+        private static XElement FindOrCreateRuleElement(XElement rules, string id)
+        {
+            var ruleElement = rules
+                              .Elements("Rule")
+                              .FirstOrDefault(r => r.Attribute("Id").Value.Equals(id));
+
+            if (ruleElement == null)
+            {
+                ruleElement = new XElement("Rule",
+                                    new XAttribute("Id", id),
+                                    new XAttribute("Action", "Warning"));
+                rules.Add(ruleElement);
+            }
+
+            return ruleElement;
+        }
+
+        private static XElement FindOrCreateRulesElement(XDocument ruleSetDocument, string analyzerID)
+        {
+            var rulesElement = ruleSetDocument.Root
+                               .Elements("Rules")
+                               .FirstOrDefault(r => r.Attribute("AnalyzerId").Value.Equals(analyzerID));
+
+            if (rulesElement == null)
+            {
+                rulesElement = new XElement("Rules",
+                                    new XAttribute("AnalyzerId", analyzerID),
+                                    new XAttribute("RuleNamespace", analyzerID));
+                ruleSetDocument.Root.Add(rulesElement);
+            }
+
+            return rulesElement;
+        }
+    }
+}

src/VisualStudio/Core/SolutionExplorerShim/SolutionExplorerShim.csproj

@@ -148,6 +148,7 @@
     <Compile Include="LocalizableProperties.cs" />
     <Compile Include="DiagnosticItem\DiagnosticItemSource.cs" />
     <Compile Include="DiagnosticItem\DiagnosticItem.cs" />
+    <Compile Include="RuleSetDocumentExtensions.cs" />
     <Compile Include="SolutionExplorerShim.Designer.cs">
       <AutoGen>True</AutoGen>
       <DesignTime>True</DesignTime>