Change file content string comparisons to be case invariant

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/FileContent.cs

@@ -127,10 +127,10 @@ internal FileContent(ILogger logger,
         public FileContent(ILogger logger, IEnumerable<string> files) : this(logger, files, new UnsafeFileReader())
         { }
 
-        private static string GetGroup(ReadOnlySpan<char> input, ValueMatch valueMatch, string groupPrefix, bool toLower)
+        private static string GetGroup(ReadOnlySpan<char> input, ValueMatch valueMatch, string groupPrefix)
         {
             var match = input.Slice(valueMatch.Index, valueMatch.Length);
-            var includeIndex = match.IndexOf(groupPrefix, StringComparison.InvariantCultureIgnoreCase);
+            var includeIndex = match.IndexOf(groupPrefix, StringComparison.OrdinalIgnoreCase);
             if (includeIndex == -1)
             {
                 return string.Empty;
@@ -141,22 +141,15 @@ private static string GetGroup(ReadOnlySpan<char> input, ValueMatch valueMatch,
             var quoteIndex1 = match.IndexOf("\"");
             var quoteIndex2 = match.Slice(quoteIndex1 + 1).IndexOf("\"");
 
-            var result = match.Slice(quoteIndex1 + 1, quoteIndex2).ToString();
-
-            if (toLower)
-            {
-                result = result.ToLowerInvariant();
-            }
-
-            return result;
+            return match.Slice(quoteIndex1 + 1, quoteIndex2).ToString();
         }
 
         private static bool IsGroupMatch(ReadOnlySpan<char> line, Regex regex, string groupPrefix, string value)
         {
             foreach (var valueMatch in regex.EnumerateMatches(line))
             {
                 // We can't get the group from the ValueMatch, so doing it manually:
-                if (GetGroup(line, valueMatch, groupPrefix, toLower: true) == value.ToLowerInvariant())
+                if (string.Equals(GetGroup(line, valueMatch, groupPrefix), value, StringComparison.OrdinalIgnoreCase))
                 {
                     return true;
                 }
@@ -172,12 +165,11 @@ private void DoInitialize()
                 {
                     foreach (ReadOnlySpan<char> line in unsafeFileReader.ReadLines(file))
                     {
-
                         // Find all the packages.
                         foreach (var valueMatch in PackageReference().EnumerateMatches(line))
                         {
                             // We can't get the group from the ValueMatch, so doing it manually:
-                            var packageName = GetGroup(line, valueMatch, "Include", toLower: true);
+                            var packageName = GetGroup(line, valueMatch, "Include").ToLowerInvariant();
                             if (!string.IsNullOrEmpty(packageName))
                             {
                                 allPackages.Add(packageName);
@@ -189,24 +181,23 @@ private void DoInitialize()
                             || IsGroupMatch(line, ProjectSdk(), "Sdk", "Microsoft.NET.Sdk.Web")
                             || IsGroupMatch(line, FrameworkReference(), "Include", "Microsoft.AspNetCore.App");
 
-
                         // Determine if implicit usings are used.
                         useImplicitUsings = useImplicitUsings
-                            || line.Contains("<ImplicitUsings>enable</ImplicitUsings>".AsSpan(), StringComparison.Ordinal)
-                            || line.Contains("<ImplicitUsings>true</ImplicitUsings>".AsSpan(), StringComparison.Ordinal);
+                            || line.Contains("<ImplicitUsings>enable</ImplicitUsings>".AsSpan(), StringComparison.OrdinalIgnoreCase)
+                            || line.Contains("<ImplicitUsings>true</ImplicitUsings>".AsSpan(), StringComparison.OrdinalIgnoreCase);
 
                         // Determine if WPF is used.
                         useWpf = useWpf
-                            || line.Contains("<UseWPF>true</UseWPF>".AsSpan(), StringComparison.Ordinal);
+                            || line.Contains("<UseWPF>true</UseWPF>".AsSpan(), StringComparison.OrdinalIgnoreCase);
 
                         // Determine if Windows Forms is used.
                         useWindowsForms = useWindowsForms
-                            || line.Contains("<UseWindowsForms>true</UseWindowsForms>".AsSpan(), StringComparison.Ordinal);
+                            || line.Contains("<UseWindowsForms>true</UseWindowsForms>".AsSpan(), StringComparison.OrdinalIgnoreCase);
 
                         // Find all custom implicit usings.
                         foreach (var valueMatch in CustomImplicitUsingDeclarations().EnumerateMatches(line))
                         {
-                            var ns = GetGroup(line, valueMatch, "Include", toLower: false);
+                            var ns = GetGroup(line, valueMatch, "Include");
                             if (!string.IsNullOrEmpty(ns))
                             {
                                 implicitUsingNamespaces.Add(ns);