Specify the Path of the Golang Executable (#755)

I enhanced GolangAppHostingExtension to define a new override of
AddGolangApp that allows specifying the path of the Golang executable
relative to the working directory. This is useful for scenarios where
the Golang executable is in a `cmd` subdirectory, but the working
directory needs to be the root of the project for accessing resources
relative to the working directory at runtime. It is also useful when
there are more than one Golang executable in a Go module.

Resolves #754

Co-authored-by: Tommaso Stocchi <tstocchi@microsoft.com>

Author: mfcollins3

src/CommunityToolkit.Aspire.Hosting.Golang/GolangAppHostingExtension.cs

@@ -30,6 +30,19 @@ public static IResourceBuilder<GolangAppExecutableResource> AddGolangApp(this ID
     /// <param name="buildTags">The optional build tags to be used when building the Golang application.</param>
     /// <returns>A reference to the <see cref="IResourceBuilder{T}"/>.</returns>
     public static IResourceBuilder<GolangAppExecutableResource> AddGolangApp(this IDistributedApplicationBuilder builder, [ResourceName] string name, string workingDirectory, string[]? args = null, string[]? buildTags = null)
+        => AddGolangApp(builder, name, workingDirectory, ".", args, buildTags);
+
+    /// <summary>
+    /// Adds a Golang application to the application model. Executes the executable Golang app.
+    /// </summary>
+    /// <param name="builder">The <see cref="IDistributedApplicationBuilder"/> to add the resource to.</param>
+    /// <param name="name">The name of the resource.</param>
+    /// <param name="workingDirectory">The working directory to use for the command. If null, the working directory of the current process is used.</param>
+    /// <param name="executable">The path to the Golang package directory or source file to be executed. Use "." to execute the program in the current directory. For example, "./cmd/server".</param>
+    /// <param name="args">The optinal arguments to be passed to the executable when it is started.</param>
+    /// <param name="buildTags">The optional build tags to be used when building the Golang application.</param>
+    /// <returns>A reference to the <see cref="IResourceBuilder{T}"/>.</returns>
+    public static IResourceBuilder<GolangAppExecutableResource> AddGolangApp(this IDistributedApplicationBuilder builder, [ResourceName] string name, string workingDirectory, string executable, string[]? args = null, string[]? buildTags = null)
     {
         ArgumentNullException.ThrowIfNull(builder, nameof(builder));
         ArgumentException.ThrowIfNullOrWhiteSpace(name, nameof(name));
@@ -43,7 +56,7 @@ public static IResourceBuilder<GolangAppExecutableResource> AddGolangApp(this ID
             allArgs.Add(string.Join(",", buildTags));
         }
 
-        allArgs.Add(".");
+        allArgs.Add(executable);
 
         if (args is { Length: > 0 })
         {

tests/CommunityToolkit.Aspire.Hosting.Golang.Tests/ResourceCreationTests.cs

@@ -58,4 +58,34 @@ public async Task GolangAppWithBuildTagsAsync()
             }
         );
     }
+
+
+    [Fact]
+    public async Task GolangAppWithExecutableAsync()
+    {
+        var builder = DistributedApplication.CreateBuilder();
+
+        builder.AddGolangApp("golang", "../../examples/golang/gin-api", "./cmd/server");
+
+        using var app = builder.Build();
+
+        var appModel = app.Services.GetRequiredService<DistributedApplicationModel>();
+
+        var resource = appModel.Resources.OfType<GolangAppExecutableResource>().SingleOrDefault();
+
+        Assert.NotNull(resource);
+
+        var args = await resource.GetArgumentValuesAsync();
+        Assert.Collection(
+            args,
+            arg =>
+            {
+                Assert.Equal("run", arg);
+            },
+            arg =>
+            {
+                Assert.Equal("./cmd/server", arg);
+            }
+        );
+    }
 }