Handle .NET core tool error differences on Linux

src/NetCoreToolService/Controllers/NewController.cs

@@ -194,6 +194,16 @@ namespace Steeltoe.NetCoreToolService.Controllers
                     return NotFound($"Template '{template}' not found.");
                 }
 
+                const string invalidOptionError = "Invalid option(s)";
+                if (newCommand.Error.Contains(invalidOptionError))
+                {
+                    var start = newCommand.Error.IndexOf(invalidOptionError, StringComparison.Ordinal) +
+                                invalidOptionError.Length;
+                    start = newCommand.Error.IndexOf("--", start, StringComparison.Ordinal) + "--".Length;
+                    var end = newCommand.Error.IndexOf('\n', start);
+                    return NotFound($"Switch '{newCommand.Error[start..end]}' not found.");
+                }
+
                 const string invalidSwitchError = "Invalid input switch:";
                 if (newCommand.Error.Contains(invalidSwitchError))
                 {

test/NetCoreToolService.Test/Controllers/NewControllerTest.cs

@@ -413,7 +413,7 @@ No templates found matching: 'nosuchtemplate'.
         }
 
         [Fact]
-        public async Task GetTemplateProject_UnknownSwitch_Should_Return_NotFound()
+        public async Task GetTemplateProject_UnknownSwitch1_Should_Return_NotFound()
         {
             // Arrange
             var executor = new Mock<ICommandExecutor>();
@@ -440,6 +440,34 @@ For a list of valid options, run 'dotnet new webapi --help'.
             notFound.Value.Should().Be("Switch 'unknown-switch' not found.");
         }
 
+        [Fact]
+        public async Task GetTemplateProject_UnknownSwitch2_Should_Return_NotFound()
+        {
+            // Arrange
+            var executor = new Mock<ICommandExecutor>();
+            executor.Setup(c =>
+                    c.ExecuteAsync($"{NetCoreTool.Command} new mytemplate --output=Sample --unknown-switch",
+                        It.IsAny<string>(), -1))
+                .ReturnsAsync(new CommandResult
+                    {
+                        ExitCode = 5,
+                        Error = @"
+Error: Invalid option(s):
+--unknown-switch
+   '--unknown-switch' is not a valid option
+",
+                    }
+                );
+            var controller = new NewController(executor.Object);
+
+            // Act
+            var result = await controller.GetTemplateProject("mytemplate", "unknown-switch");
+
+            // Assert
+            var notFound = Assert.IsType<NotFoundObjectResult>(result);
+            notFound.Value.Should().Be("Switch 'unknown-switch' not found.");
+        }
+
         [Fact]
         public async Task GetTemplateProject_UnknownParameter_Should_Return_NotFound()
         {