Make --verbosity case insensitive (#2300)

Fixes #2179

Author: nohwnd

src/Microsoft.TestPlatform.Build/Tasks/VSTestTask.cs

@@ -247,11 +247,11 @@ private List<string> AddArgs()
                 var quietTestLogging = new List<string>() {"q", "quiet"};
 
                 string vsTestVerbosity = "minimal";
-                if (normalTestLogging.Contains(this.VSTestVerbosity))
+                if (normalTestLogging.Contains(this.VSTestVerbosity.ToLowerInvariant()))
                 {
                     vsTestVerbosity = "normal";
                 }
-                else if (quietTestLogging.Contains(this.VSTestVerbosity))
+                else if (quietTestLogging.Contains(this.VSTestVerbosity.ToLowerInvariant()))
                 {
                     vsTestVerbosity = "quiet";
                 }

test/Microsoft.TestPlatform.Build.UnitTests/VsTestTaskTests.cs

@@ -188,6 +188,26 @@ public void CreateArgumentShouldSetConsoleLoggerVerbosityToMinimalIfConsoleLogge
             Assert.IsNotNull(allArguments.FirstOrDefault(arg => arg.Contains("--logger:Console;Verbosity=minimal")));
         }
 
+        [TestMethod]
+        public void CreateArgumentShouldSetConsoleLoggerVerbosityToNormalIfConsoleLoggerIsNotGivenInArgsAndVerbosityIsNormalWithCapitalN()
+        {
+            this.vsTestTask.VSTestVerbosity = "Normal";
+
+            var allArguments = this.vsTestTask.CreateArgument().ToArray();
+
+            Assert.IsNotNull(allArguments.FirstOrDefault(arg => arg.Contains("--logger:Console;Verbosity=normal")));
+        }
+
+        [TestMethod]
+        public void CreateArgumentShouldSetConsoleLoggerVerbosityToQuietIfConsoleLoggerIsNotGivenInArgsAndVerbosityIsQuietWithCapitalQ()
+        {
+            this.vsTestTask.VSTestVerbosity = "Quiet";
+
+            var allArguments = this.vsTestTask.CreateArgument().ToArray();
+
+            Assert.IsNotNull(allArguments.FirstOrDefault(arg => arg.Contains("--logger:Console;Verbosity=quiet")));
+        }
+
         [TestMethod]
         public void CreateArgumentShouldPreserveWhiteSpaceInLogger()
         {