impl show-topic command

src/Steeltoe.Cli/ShowTopicCommand.cs

@@ -12,8 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-using System;
+using System.IO;
+using System.Linq;
+using System.Reflection;
 using McMaster.Extensions.CommandLineUtils;
+using Microsoft.Extensions.Logging;
+using Steeltoe.Tooling;
 using Steeltoe.Tooling.Controllers;
 
 namespace Steeltoe.Cli
@@ -32,7 +36,7 @@ Examples:
         public const string CommandName = "show-topic";
 
         [Argument(0, Name = "topic", Description = "Topic")]
-        private string Topic { get; set; }
+        private string Topic { get; } = null;
 
         public ShowTopicCommand(IConsole console) : base(console)
         {
@@ -40,7 +44,66 @@ Examples:
 
         protected override Controller GetController()
         {
-            throw new NotImplementedException();
+            return new ShowTopicController(Topic);
+        }
+
+        private class ShowTopicController : Controller
+        {
+            private static readonly ILogger<ShowTopicController> Logger =
+                Logging.LoggerFactory.CreateLogger<ShowTopicController>();
+
+            private readonly string _topicsPath = Path.Combine(
+                Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location),
+                "steeltoe.rc",
+                "topics");
+
+            private readonly string _topic;
+
+            public ShowTopicController(string topic)
+            {
+                _topic = topic;
+            }
+
+            protected override void Execute()
+            {
+                Logger.LogDebug($"topics path: {_topicsPath}");
+                if (_topic == null)
+                {
+                    ListTopics();
+                }
+                else
+                {
+                    ShowTopic(_topic);
+                }
+            }
+
+            private void ListTopics()
+            {
+                var topicPaths = Directory.GetFiles(_topicsPath, "*.txt");
+                var maxTopicLength = topicPaths.Select(Path.GetFileNameWithoutExtension)
+                    .Select(topic => topic.Length).Concat(new[] {0}).Max();
+                var descriptionColumn = maxTopicLength + 4;
+                foreach (var topicPath in topicPaths)
+                {
+                    var topic = Path.GetFileNameWithoutExtension(topicPath);
+                    var description = File.ReadLines(topicPath).First();
+                    Context.Console.WriteLine($"{topic.PadRight(descriptionColumn)}{description}");
+                }
+            }
+
+            private void ShowTopic(string topic)
+            {
+                var topicPath = Path.Combine(_topicsPath, $"{topic}.txt");
+                if (!File.Exists(topicPath))
+                {
+                    throw new ItemDoesNotExistException(topic);
+                }
+
+                foreach (var line in File.ReadLines(topicPath))
+                {
+                    Context.Console.WriteLine(line);
+                }
+            }
         }
     }
 }

src/Steeltoe.Tooling/Shell.cs

@@ -20,7 +20,7 @@ namespace Steeltoe.Tooling
     public abstract class Shell
     {
         /// <summary>
-        /// Implemetations return the result of running a command.
+        /// Implementations return the result of running a command.
         /// </summary>
         /// <param name="command">System command.</param>
         /// <param name="args">Command arguments.</param>

src/Steeltoe.Tooling/steeltoe.rc/topics/autodetection.txt

@@ -0,0 +1,38 @@
+Application and Service Autodetection
+
+  Application Autodetection
+
+    Name
+      The application name is determined, in order of precedence:
+      *  The value of the –-name option
+      *  The output directory name if the output directory contains the file <name>.csproj
+      *  The file name <name>.csproj if the output directory contains one and only file with extension .csproj
+      If none of the above is satisfied, an error occurs.
+
+    Framework
+      The application framework is determined, in order of precedence:
+      *  The value of the  –-framework option
+      *  The value of the <TargetFramework> element in the project .csproj file
+      *  The first framework listed in the <TargetFrameworks> element in the project .csproj file
+      If none of the above is satisfied, an error occurs.
+
+  Service Autodetection
+      Services are autodetected by searching a project’s .csproj file for the presence of any of a service’s dependencies.
+      A dependency is considered present if any of the .csproj file elements matches one of the following XPath expressions:
+          /Project/ItemGroup/PackageReference[@Include='<dep>']
+          /Project/ItemGroup/Reference[@Include='<dep>']
+
+      Examples:
+      * A project with a dependency on RabbitMQ:
+          <Project>
+            <ItemGroup>
+              <PackageReference Include="RabbitMQ.Client" />
+            </ItemGroup>
+          </Project>
+
+      * A project with a dependency on GemFire:
+          <Project>
+            <ItemGroup>
+              <Reference Include="Pivotal.GemFire" />
+            </ItemGroup>
+          </Project>

test/Steeltoe.Cli.Test/FeatureSpecs.cs

@@ -170,9 +170,17 @@ namespace scratch
 
             var actualMessages = actual.ToArray();
 
-            // '*' denotes we don't care
+            // '*' denotes we don't care about this line
+            // '***' denotes we don't care about any further lines
             for (var i = 0; i < messages.Length; ++i)
             {
+                if (messages[i] == "***")
+                {
+                    Array.Resize(ref messages, i);
+                    Array.Resize(ref actualMessages, i);
+                    break;
+                }
+
                 if (messages[i] == "*")
                 {
                     actualMessages[i] = "*";

test/Steeltoe.Cli.Test/ShowTopicFeature.cs

@@ -23,7 +23,7 @@ namespace Steeltoe.Cli.Test
         public void ShowTopicHelp()
         {
             Runner.RunScenario(
-                given => a_dotnet_project("show_topic_help"),
+                given => an_empty_directory("show_topic_help"),
                 when => the_developer_runs_cli_command("show-topic --help"),
                 then => the_cli_command_should_succeed(),
                 and => the_cli_should_output(new[]
@@ -47,10 +47,50 @@ namespace Steeltoe.Cli.Test
         public void ShowTopicTooManyArgs()
         {
             Runner.RunScenario(
-                given => a_dotnet_project("show_topic_too_many_args"),
+                given => an_empty_directory("show_topic_too_many_args"),
                 when => the_developer_runs_cli_command("show-topic arg1 arg2"),
                 then => the_cli_should_fail_parse("Unrecognized command or argument 'arg2'")
             );
         }
+
+        [Scenario]
+        public void ShowTopicList()
+        {
+            Runner.RunScenario(
+                given => an_empty_directory("show_topic_list"),
+                when => the_developer_runs_cli_command("show-topic"),
+                then => the_cli_command_should_succeed(),
+                and => the_cli_should_output(new[]
+                {
+                    "autodetection Application and Service Autodetection",
+                })
+            );
+        }
+
+        [Scenario]
+        public void ShowTopicNotFound()
+        {
+            Runner.RunScenario(
+                given => an_empty_directory("show_topic_not_found"),
+                when => the_developer_runs_cli_command("show-topic no-such-topic"),
+                then => the_cli_should_error(ErrorCode.Tooling, "'no-such-topic' does not exist")
+            );
+        }
+
+        [Scenario]
+        public void ShowTopicAutodetection()
+        {
+            Runner.RunScenario(
+                given => an_empty_directory("show_topic_autodetection"),
+                when => the_developer_runs_cli_command("show-topic autodetection"),
+                then => the_cli_command_should_succeed(),
+                and => the_cli_should_output(new[]
+                {
+                    "Application and Service Autodetection",
+                    "Application Autodetection",
+                    "***",
+                })
+            );
+        }
     }
 }