fix #864, make consts private

Author: jonsequitur

src/System.CommandLine.Suggest.Tests/DotnetSuggestEndToEndTests.cs

@@ -56,7 +56,7 @@ public DotnetSuggestEndToEndTests(ITestOutputHelper output)
 
             _environmentVariables = new[] {
                 ("DOTNET_ROOT", _dotnetHostDir.FullName),
-                (FileSuggestionRegistration.TestDirectroyOverride, _testRoot)};
+                (TestDirectroyOverride: "INTERNAL_TEST_DOTNET_SUGGEST_HOME", _testRoot)};
         }
 
         public void Dispose()

src/System.CommandLine.Suggest/FileSuggestionRegistration.cs

@@ -10,8 +10,8 @@ namespace System.CommandLine.Suggest
 {
     public class FileSuggestionRegistration : ISuggestionRegistration
     {
-        public const string ResgistrationFileName = ".dotnet-suggest-registration.txt";
-        public const string TestDirectroyOverride = "INTERNAL_TEST_DOTNET_SUGGEST_HOME";
+        private const string RegistrationFileName = ".dotnet-suggest-registration.txt";
+        private const string TestDirectoryOverride = "INTERNAL_TEST_DOTNET_SUGGEST_HOME";
         private readonly string _registrationConfigurationFilePath;
 
         public FileSuggestionRegistration(string registrationsConfigurationFilePath = null)
@@ -22,18 +22,16 @@ public FileSuggestionRegistration(string registrationsConfigurationFilePath = nu
                 return;
             }
 
-            var testDirectoryOverride = GetEnvironmentVariable(TestDirectroyOverride);
+            var testDirectoryOverride = GetEnvironmentVariable(TestDirectoryOverride);
             if (!string.IsNullOrWhiteSpace(testDirectoryOverride))
             {
-                _registrationConfigurationFilePath = Path.Combine(testDirectoryOverride, ResgistrationFileName);
+                _registrationConfigurationFilePath = Path.Combine(testDirectoryOverride, RegistrationFileName);
                 return;
             }
 
             var userProfile = GetFolderPath(SpecialFolder.UserProfile);
-            if (userProfile != null)
-            {
-                _registrationConfigurationFilePath = Path.Combine(userProfile, ResgistrationFileName);
-            }
+            
+            _registrationConfigurationFilePath = Path.Combine(userProfile, RegistrationFileName);
         }
 
         public Registration FindRegistration(FileInfo soughtExecutable)