Redirect parser to localized validation messages

test/dotnet.Tests/ParserTests/ValdidationMessageTests.cs

@@ -0,0 +1,73 @@
+// 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 FluentAssertions;
+using Microsoft.DotNet.Cli.CommandLine;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Microsoft.DotNet.Tests.ParserTests
+{
+    public class ValidationMessageTests
+    {
+        private readonly ITestOutputHelper output;
+
+        [Fact]
+        public void ValidationMessagesFormatCorrectly()
+        {
+            // Since not all validation messages that we provided to the command-line parser are triggered by our
+            // tests (and some may not be possible to trigger with our current usage), unit test  that we can 
+            // obtain validation messages through the same interface as the command-line parser.
+            //
+            // In English configuration, we check that the messages are exactly what we expect and otherwise we at
+            // lest ensure that we don't get a FormatException.
+
+            IValidationMessages m = new CommandLineValidationMessages();
+
+            m.CommandAcceptsOnlyOneArgument("xyz", 3)
+             .Should().BeVisuallyEquivalentToIfNotLocalized(
+                 "Command 'xyz' only accepts a single argument but 3 were provided.");
+
+            m.CommandAcceptsOnlyOneSubcommand("zyx", "a;b;c")
+             .Should().BeVisuallyEquivalentToIfNotLocalized(
+                "Command 'zyx' only accepts a single subcommand but multiple were provided: a;b;c");
+
+            m.FileDoesNotExist("abc.def")
+              .Should().BeVisuallyEquivalentToIfNotLocalized(
+                "File does not exist: abc.def");
+
+            m.NoArgumentsAllowed("zzz")
+            .Should().BeVisuallyEquivalentToIfNotLocalized(
+                "Arguments not allowed for option: zzz");
+
+            m.OptionAcceptsOnlyOneArgument("qqq", 4)
+             .Should().BeVisuallyEquivalentToIfNotLocalized(
+                "Option 'qqq' only accepts a single argument but 4 were provided.");
+
+            m.RequiredArgumentMissingForCommand("www")
+             .Should().BeVisuallyEquivalentToIfNotLocalized(
+                "Required argument missing for command: www");
+
+            m.RequiredArgumentMissingForOption("rrr")
+             .Should().BeVisuallyEquivalentToIfNotLocalized(
+                 "Required argument missing for option: rrr");
+
+            m.RequiredCommandWasNotProvided()
+             .Should().BeVisuallyEquivalentToIfNotLocalized(
+                 "Required command was not provided.");
+
+            m.UnrecognizedArgument("apple", new[] { "banana", "orange" })
+              .Should().BeVisuallyEquivalentToIfNotLocalized(
+                 "Argument 'apple' not recognized. Must be one of: \n\t'banana'\n\t\'orange'");
+
+            m.UnrecognizedCommandOrArgument("ppp")
+              .Should().BeVisuallyEquivalentToIfNotLocalized(
+                 "Unrecognized command or argument 'ppp'");
+
+            m.UnrecognizedOption("apple", new[] { "banana", "orange" })
+              .Should().BeVisuallyEquivalentToIfNotLocalized(
+                 "Option 'apple' not recognized. Must be one of: \n\t'banana'\n\t\'orange'");
+        }
+    }
+}