Fixes broken unit test

Author: svengeance

src/GitVersionExe.Tests/ArgumentParserTests.cs

@@ -320,7 +320,7 @@ public void CreateMulitpleAssemblyInfoProtected(string command)
             exception.Message.ShouldBe("Can't specify multiple assembly info files when using /ensureassemblyinfo switch, either use a single assembly info file or do not specify /ensureassemblyinfo and create assembly info files manually");
         }
 
-        [TestCase("-updateProjectFiles Assembly.csproj Assembly1.csproj -ensureassemblyinfo")]
+        [TestCase("-updateProjectFiles Assembly.csproj -ensureassemblyinfo")]
         public void UpdateProjectInfoWithEnsureAssemblyInfoProtected(string command)
         {
             var exception = Assert.Throws<WarningException>(() => argumentParser.ParseArguments(command));

src/GitVersionExe/ArgumentParser.cs

@@ -424,6 +424,11 @@ private static void ParseEnsureAssemblyInfo(Arguments arguments, string value)
                 arguments.EnsureAssemblyInfo = false;
             }
 
+            if (arguments.UpdateProjectFiles)
+            {
+                throw new WarningException("Cannot specify -ensureassemblyinfo with updateprojectfiles: please ensure your project file exists before attempting to update it");
+            }
+
             if (arguments.UpdateAssemblyInfoFileName.Count > 1 && arguments.EnsureAssemblyInfo)
             {
                 throw new WarningException("Can't specify multiple assembly info files when using /ensureassemblyinfo switch, either use a single assembly info file or do not specify /ensureassemblyinfo and create assembly info files manually");