Add Go Build Tags Support

I updated GolangAppHostingExtension to support specifying Go build tags
to be used when building and running Go applications. Go build tags can
be used to include or exclude files from the build process based On
specific conditions. For example, when using Aspire for development, a
Go developer may use a build tag to enable special code for
OpenTelemetry instrumentation or enable debugging features.

Closes #730

Author: Michael Collins

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

@@ -15,16 +15,27 @@ public static class GolangAppHostingExtension
     /// <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="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[]? args = null)
+    public static IResourceBuilder<GolangAppExecutableResource> AddGolangApp(this IDistributedApplicationBuilder builder, [ResourceName] string name, string workingDirectory, string[]? args = null, string[]? buildTags = null)
     {
         ArgumentNullException.ThrowIfNull(builder, nameof(builder));
         ArgumentException.ThrowIfNullOrWhiteSpace(name, nameof(name));
         ArgumentException.ThrowIfNullOrWhiteSpace(workingDirectory, nameof(workingDirectory));
 
-        string[] allArgs = args is { Length: > 0 }
-            ? ["run", ".", .. args]
-            : ["run", ".",];
+        string[] allArgs;
+        if (buildTags is { Length: > 0 })
+        {
+            allArgs = args is { Length: > 0 }
+                ? ["run", "-tags", string.Join(",", buildTags), ".", .. args ?? []]
+                : ["run", "-tags", string.Join(",", buildTags), "."];
+        }
+        else
+        {
+            allArgs = args is { Length: > 0 }
+                ? ["run", ".", .. args]
+                : ["run", ".",];
+        }
 
         workingDirectory = Path.Combine(builder.AppHostDirectory, workingDirectory).NormalizePathForCurrentPlatform();
         var resource = new GolangAppExecutableResource(name, workingDirectory);

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

@@ -21,4 +21,41 @@ public void DefaultGolangApp()
 
         Assert.Equal("go", resource.Command);
     }
+
+    [Fact]
+    public async Task GolangAppWithBuildTagsAsync()
+    {
+        var builder = DistributedApplication.CreateBuilder();
+
+        builder.AddGolangApp("golang", "../../examples/golang/gin-api", buildTags: ["dev"]);
+
+        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("-tags", arg);
+            },
+            arg =>
+            {
+                Assert.Equal("dev", arg);
+            },
+            arg =>
+            {
+                Assert.Equal(".", arg);
+            }
+        );
+    }
 }