Fix MsTest exception message parsing (#848)

src/Verify.ExceptionParsing.Tests/ExceptionParsingTests.MsTest.verified.txt

@@ -0,0 +1,8 @@
+{
+  NotEqual: [
+    {
+      Received: {CurrentDirectory}XAMLCombinerTests.TestOutput.received.xaml,
+      Verified: {CurrentDirectory}XAMLCombinerTests.TestOutput.verified.xaml
+    }
+  ]
+}

src/Verify.ExceptionParsing.Tests/ExceptionParsingTests.cs

@@ -115,6 +115,39 @@ public Task Nunit()
         return Verify(result);
     }
 
+    [Fact]
+    public Task MsTest()
+    {
+        var exceptionMessage = $"""
+            Test method TheTests.XAMLCombinerTests.TestOutput threw exception: 
+            VerifyException : Directory: {Environment.CurrentDirectory}
+            NotEqual:
+              - Received: XAMLCombinerTests.TestOutput.received.xaml
+                Verified: XAMLCombinerTests.TestOutput.verified.xaml
+
+            FileContent:
+
+            NotEqual:
+
+            Received: XAMLCombinerTests.TestOutput.received.xaml
+            <?xml version="1.0" encoding="utf-8"?>
+            <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:sys="clr-namespace:System;assembly=mscorlib" xmlns:sys_0="clr-namespace:System;assembly=System.Runtime">
+              <Style x:Key="Control1" />
+              <Color x:Key="Control1_Color">#FF2B579A</Color>
+              <sys:String x:Key="string1">stringValue</sys:String>
+              <Style x:Key="Control2" />
+              <Color x:Key="Control2_Color">#FF2B579A</Color>
+              <sys:String x:Key="string2">stringValue</sys:String>
+              <sys_0:String x:Key="string3">stringValue</sys_0:String>
+              <Style TargetType="Block" />
+            </ResourceDictionary>
+            Verified: XAMLCombinerTests.TestOutput.verified.xaml
+            """;
+
+        var result = Parser.Parse(exceptionMessage);
+        return Verify(result);
+    }
+
     [Fact]
     public Task SingleNotEqual()
     {

src/Verify.ExceptionParsing/Parser.cs

@@ -39,6 +39,17 @@ static Result InnerParse(IEnumerable<string> lines)
             }
 
             var firstLine = enumerator.Current!;
+            //MsTest exception start with "Test method..." so lets swallow them
+            if (firstLine.StartsWith("Test method"))
+            {
+                if (!enumerator.MoveNext())
+                {
+                    throw new ParseException("No content");
+                }
+
+                firstLine = enumerator.Current!;
+            }
+
             var directory = GetDirectory(firstLine);
 
             while (enumerator.MoveNext())