refactoring .stylecop.json changes

Author: dotarj

StyleCop.Analyzers/StyleCop.Analyzers.Test/Settings/SettingsFileCodeFixProviderUnitTests.cs

@@ -79,7 +79,7 @@ public async Task TestSettingsFileAlreadyExistsAsync()
         public async Task TestDotPrefixedSettingsFileAlreadyExistsAsync()
         {
             this.createSettingsFile = true;
-            this.settingsFileName = $".{SettingsHelper.SettingsFileName}";
+            this.settingsFileName = SettingsHelper.AltSettingsFileName;
 
             var offeredFixes = await this.GetOfferedCSharpFixesAsync(TestCode).ConfigureAwait(false);
             Assert.Empty(offeredFixes);

StyleCop.Analyzers/StyleCop.Analyzers.Test/SpecialRules/SA0002UnitTests.cs

@@ -278,7 +278,7 @@ public void TestUnexpectedExceptionNotCaught()
             Assert.Null(additionalFiles[0].Path);
             Assert.Null(additionalFiles[0].GetText(CancellationToken.None));
             var context = new CompilationAnalysisContext(compilation: null, options: new AnalyzerOptions(additionalFiles), reportDiagnostic: null, isSupportedDiagnostic: null, cancellationToken: CancellationToken.None);
-            Assert.Throws<NullReferenceException>(() => analysisContext.CompilationAction(context));
+            Assert.Throws<ArgumentNullException>(() => analysisContext.CompilationAction(context));
         }
 
         /// <inheritdoc/>

StyleCop.Analyzers/StyleCop.Analyzers/Settings/SettingsHelper.cs

@@ -3,6 +3,7 @@
 
 namespace StyleCop.Analyzers
 {
+    using System;
     using System.Collections.Immutable;
     using System.IO;
     using System.Threading;
@@ -18,6 +19,7 @@ namespace StyleCop.Analyzers
     internal static class SettingsHelper
     {
         internal const string SettingsFileName = "stylecop.json";
+        internal const string AltSettingsFileName = ".stylecop.json";
 
         private static readonly SourceTextValueProvider<StyleCopSettings> SettingsValueProvider =
             new SourceTextValueProvider<StyleCopSettings>(
@@ -73,14 +75,15 @@ internal static StyleCopSettings GetStyleCopSettings(this AnalyzerOptions option
         /// <returns><c>true</c> if <paramref name="path"/> points to a StyleCop settings file; otherwise, <c>false</c>.</returns>
         internal static bool IsStyleCopSettingsFile(string path)
         {
-            var fileName = Path.GetFileName(path).ToLowerInvariant();
-
-            if (fileName.StartsWith("."))
+            if (path == null)
             {
-                fileName = fileName.Substring(1);
+                throw new ArgumentNullException(nameof(path));
             }
 
-            return fileName == SettingsFileName;
+            var fileName = Path.GetFileName(path);
+
+            return string.Equals(fileName, SettingsFileName, StringComparison.OrdinalIgnoreCase)
+                || string.Equals(fileName, AltSettingsFileName, StringComparison.OrdinalIgnoreCase);
         }
 
         internal static StyleCopSettings GetStyleCopSettings(this AnalysisContext context, AnalyzerOptions options, CancellationToken cancellationToken)
@@ -90,8 +93,8 @@ internal static StyleCopSettings GetStyleCopSettings(this AnalysisContext contex
 
         internal static StyleCopSettings GetStyleCopSettings(this AnalysisContext context, AnalyzerOptions options, DeserializationFailureBehavior failureBehavior, CancellationToken cancellationToken)
         {
-            string settingsFileName;
-            SourceText text = TryGetStyleCopSettingsText(options, cancellationToken, out settingsFileName);
+            string settingsFilePath;
+            SourceText text = TryGetStyleCopSettingsText(options, cancellationToken, out settingsFilePath);
             if (text == null)
             {
                 return new StyleCopSettings();
@@ -108,7 +111,7 @@ internal static StyleCopSettings GetStyleCopSettings(this AnalysisContext contex
                 return settings;
             }
 
-            return GetStyleCopSettings(settingsFileName, text, failureBehavior);
+            return GetStyleCopSettings(settingsFilePath, text, failureBehavior);
         }
 
         internal static StyleCopSettings GetStyleCopSettings(this CompilationStartAnalysisContext context, AnalyzerOptions options, CancellationToken cancellationToken)
@@ -120,8 +123,8 @@ internal static StyleCopSettings GetStyleCopSettings(this CompilationStartAnalys
         internal static StyleCopSettings GetStyleCopSettings(this CompilationStartAnalysisContext context, AnalyzerOptions options, DeserializationFailureBehavior failureBehavior, CancellationToken cancellationToken)
 #pragma warning restore RS1012 // Start action has no registered actions.
         {
-            string settingsFileName;
-            SourceText text = TryGetStyleCopSettingsText(options, cancellationToken, out settingsFileName);
+            string settingsFilePath;
+            SourceText text = TryGetStyleCopSettingsText(options, cancellationToken, out settingsFilePath);
             if (text == null)
             {
                 return new StyleCopSettings();
@@ -138,7 +141,7 @@ internal static StyleCopSettings GetStyleCopSettings(this CompilationStartAnalys
                 return settings;
             }
 
-            return GetStyleCopSettings(settingsFileName, text, failureBehavior);
+            return GetStyleCopSettings(settingsFilePath, text, failureBehavior);
         }
 
         private static StyleCopSettings GetStyleCopSettings(string path, SourceText text, DeserializationFailureBehavior failureBehavior)
@@ -178,19 +181,19 @@ private static StyleCopSettings GetStyleCopSettings(string path, SourceText text
             return new StyleCopSettings();
         }
 
-        private static SourceText TryGetStyleCopSettingsText(this AnalyzerOptions options, CancellationToken cancellationToken, out string settingsFileName)
+        private static SourceText TryGetStyleCopSettingsText(this AnalyzerOptions options, CancellationToken cancellationToken, out string settingsFilePath)
         {
             foreach (var additionalFile in options.AdditionalFiles)
             {
                 if (IsStyleCopSettingsFile(additionalFile.Path))
                 {
-                    settingsFileName = additionalFile.Path;
+                    settingsFilePath = additionalFile.Path;
 
                     return additionalFile.GetText(cancellationToken);
                 }
             }
 
-            settingsFileName = null;
+            settingsFilePath = null;
 
             return null;
         }