Fix migrate command's parse error

argument. So, when it is trying to materialize MigrateCommand, the file
path does not match what it is expected(a bool).

test/dotnet.Tests/ParserTests/MigrateParserTests.cs

@@ -0,0 +1,58 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Linq;
+using FluentAssertions;
+using Microsoft.DotNet.Cli.CommandLine;
+using Microsoft.DotNet.Tools.Migrate;
+using Xunit;
+using Xunit.Abstractions;
+using Parser = Microsoft.DotNet.Cli.Parser;
+
+namespace Microsoft.DotNet.Tests.ParserTests
+{
+    public class MigrateParserTests
+    {
+        public MigrateParserTests(ITestOutputHelper output)
+        {
+            this.output = output;
+        }
+
+        private readonly ITestOutputHelper output;
+
+        [Fact]
+        public void MigrateParserConstructMigrateCommandWithoutError()
+        {
+            var command = Parser.Instance;
+
+            var result = command.Parse("dotnet migrate --skip-backup -s " +
+                                       "-x \"C:\\ConsoleAppOnCore_1\\ConsoleAppOnCore_1.xproj\" " +
+                                       "\"C:\\ConsoleAppOnCore_1\\project.json\" " +
+                                       "-r \"C:\\report.wfw\" " +
+                                       "--format-report-file-json");
+
+            Action a = () => result["dotnet"]["migrate"].Value<MigrateCommand>();
+            a.ShouldNotThrow<ParseException>();
+        }
+
+        [Fact]
+        public void MigrateParseGetResultCorrectlyAsFollowing()
+        {
+            var command = Parser.Instance;
+
+            var result = command.Parse("dotnet migrate --skip-backup -s " +
+                                       "-x \"C:\\ConsoleAppOnCore_1\\ConsoleAppOnCore_1.xproj\" " +
+                                       "\"C:\\ConsoleAppOnCore_1\\project.json\" " +
+                                       "-r \"C:\\report.wfw\" " +
+                                       "--format-report-file-json");
+
+            result["dotnet"]["migrate"]["skip-backup"].Value<bool>().Should().BeTrue();
+            result["dotnet"]["migrate"]["skip-project-references"].Value<bool>().Should().BeTrue();
+            result["dotnet"]["migrate"]["format-report-file-json"].Value<bool>().Should().BeTrue();
+            result["dotnet"]["migrate"]["xproj-file"].Value<string>().Should().Be("C:\\ConsoleAppOnCore_1\\ConsoleAppOnCore_1.xproj");
+            result["dotnet"]["migrate"]["report-file"].Value<string>().Should().Be("C:\\report.wfw");
+            result["dotnet"]["migrate"].Arguments.Contains("C:\\ConsoleAppOnCore_1\\project.json").Should().BeTrue();
+        }
+    }
+}