Add NuGet.config creation to solution initialization in aspire init

src/Aspire.Cli/Commands/InitCommand.cs

@@ -249,6 +249,14 @@ ServiceDefaults project contains helper code to make it easier
 
         // Get template version/channel selection using the same logic as NewCommand
         var selectedTemplateDetails = await GetProjectTemplatesVersionAsync(parseResult, cancellationToken);
+
+        // Create or update NuGet.config for explicit channels in the solution directory
+        // This matches the behavior of 'aspire new' when creating in-place
+        var nugetConfigPrompter = new NuGetConfigPrompter(InteractionService);
+        await nugetConfigPrompter.PromptToCreateOrUpdateAsync(
+            ExecutionContext.WorkingDirectory,
+            selectedTemplateDetails.Channel,
+            cancellationToken);
 
         // Create a temporary directory for the template output
         var tempProjectDir = Path.Combine(Path.GetTempPath(), $"aspire-init-{Guid.NewGuid()}");

src/Aspire.Cli/Packaging/NuGetConfigPrompter.cs

@@ -0,0 +1,105 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Aspire.Cli.Interaction;
+using Aspire.Cli.Resources;
+
+namespace Aspire.Cli.Packaging;
+
+/// <summary>
+/// Handles prompting users to create or update NuGet.config files for explicit package channels.
+/// </summary>
+internal class NuGetConfigPrompter
+{
+    private readonly IInteractionService _interactionService;
+
+    public NuGetConfigPrompter(IInteractionService interactionService)
+    {
+        ArgumentNullException.ThrowIfNull(interactionService);
+        _interactionService = interactionService;
+    }
+
+    /// <summary>
+    /// Prompts to create or update a NuGet.config for explicit channels.
+    /// Always prompts the user before creating or updating the file.
+    /// </summary>
+    /// <param name="targetDirectory">The directory where the NuGet.config should be created or updated.</param>
+    /// <param name="channel">The package channel providing mapping information.</param>
+    /// <param name="cancellationToken">A cancellation token to observe while waiting for the task to complete.</param>
+    public async Task PromptToCreateOrUpdateAsync(DirectoryInfo targetDirectory, PackageChannel channel, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(targetDirectory);
+        ArgumentNullException.ThrowIfNull(channel);
+
+        if (channel.Type is not PackageChannelType.Explicit)
+        {
+            return;
+        }
+
+        var mappings = channel.Mappings;
+        if (mappings is null || mappings.Length == 0)
+        {
+            return;
+        }
+
+        var hasConfigInTargetDir = NuGetConfigMerger.TryFindNuGetConfigInDirectory(targetDirectory, out var nugetConfigFile);
+        var hasMissingSources = hasConfigInTargetDir && NuGetConfigMerger.HasMissingSources(targetDirectory, channel);
+
+        if (!hasConfigInTargetDir)
+        {
+            // Ask for confirmation before creating the file
+            var choice = await _interactionService.PromptForSelectionAsync(
+                TemplatingStrings.CreateNugetConfigConfirmation,
+                [TemplatingStrings.Yes, TemplatingStrings.No],
+                c => c,
+                cancellationToken);
+
+            if (string.Equals(choice, TemplatingStrings.Yes, StringComparisons.CliInputOrOutput))
+            {
+                await NuGetConfigMerger.CreateOrUpdateAsync(targetDirectory, channel, cancellationToken: cancellationToken);
+                _interactionService.DisplayMessage("package", TemplatingStrings.NuGetConfigCreatedConfirmationMessage);
+            }
+        }
+        else if (hasMissingSources)
+        {
+            var updateChoice = await _interactionService.PromptForSelectionAsync(
+                "Update NuGet.config to add missing package sources for the selected channel?",
+                [TemplatingStrings.Yes, TemplatingStrings.No],
+                c => c,
+                cancellationToken);
+
+            if (string.Equals(updateChoice, TemplatingStrings.Yes, StringComparisons.CliInputOrOutput))
+            {
+                await NuGetConfigMerger.CreateOrUpdateAsync(targetDirectory, channel, cancellationToken: cancellationToken);
+                _interactionService.DisplayMessage("package", "Updated NuGet.config with required package sources.");
+            }
+        }
+    }
+
+    /// <summary>
+    /// Creates or updates a NuGet.config for explicit channels without prompting.
+    /// This is used when creating projects in subdirectories where the behavior is expected.
+    /// </summary>
+    /// <param name="targetDirectory">The directory where the NuGet.config should be created or updated.</param>
+    /// <param name="channel">The package channel providing mapping information.</param>
+    /// <param name="cancellationToken">A cancellation token to observe while waiting for the task to complete.</param>
+    public async Task CreateOrUpdateWithoutPromptAsync(DirectoryInfo targetDirectory, PackageChannel channel, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(targetDirectory);
+        ArgumentNullException.ThrowIfNull(channel);
+
+        if (channel.Type is not PackageChannelType.Explicit)
+        {
+            return;
+        }
+
+        var mappings = channel.Mappings;
+        if (mappings is null || mappings.Length == 0)
+        {
+            return;
+        }
+
+        await NuGetConfigMerger.CreateOrUpdateAsync(targetDirectory, channel, cancellationToken: cancellationToken);
+        _interactionService.DisplayMessage("package", "Created or updated NuGet.config in the project directory with required package sources.");
+    }
+}

src/Aspire.Cli/Templating/DotNetTemplateFactory.cs

@@ -480,60 +480,19 @@ private async Task PromptToCreateOrUpdateNuGetConfigAsync(PackageChannel channel
         var normalizedWorkingPath = workingDir.FullName;
         var isInPlaceCreation = string.Equals(normalizedOutputPath, normalizedWorkingPath, StringComparison.OrdinalIgnoreCase);
 
+        var nugetConfigPrompter = new NuGetConfigPrompter(interactionService);
+
         if (!isInPlaceCreation)
         {
             // For subdirectory creation, always create/update NuGet.config in the output directory only
             // and ignore any existing NuGet.config in the working directory
-            await NuGetConfigMerger.CreateOrUpdateAsync(outputDir, channel, cancellationToken: cancellationToken);
-            interactionService.DisplayMessage("package", "Created or updated NuGet.config in the project directory with required package sources.");
+            await nugetConfigPrompter.CreateOrUpdateWithoutPromptAsync(outputDir, channel, cancellationToken);
             return;
         }
 
         // In-place creation: preserve existing behavior
-        // Check if we need to create or update a NuGet.config in the working directory
-        var hasConfigInWorkingDir = TryFindNuGetConfigInDirectory(workingDir, out var nugetConfigFile);
-        var hasMissingSources = hasConfigInWorkingDir && NuGetConfigMerger.HasMissingSources(workingDir, channel);
-
-        if (!hasConfigInWorkingDir)
-        {
-            // Ask for confirmation before creating the file
-            var choice = await interactionService.PromptForSelectionAsync(
-                TemplatingStrings.CreateNugetConfigConfirmation,
-                [TemplatingStrings.Yes, TemplatingStrings.No],
-                c => c,
-                cancellationToken);
-
-            if (string.Equals(choice, TemplatingStrings.Yes, StringComparisons.CliInputOrOutput))
-            {
-                await NuGetConfigMerger.CreateOrUpdateAsync(outputDir, channel, cancellationToken: cancellationToken);
-                interactionService.DisplayMessage("package", TemplatingStrings.NuGetConfigCreatedConfirmationMessage);
-            }
-        }
-        else if (hasMissingSources)
-        {
-            var updateChoice = await interactionService.PromptForSelectionAsync(
-                "Update NuGet.config to add missing package sources for the selected channel?",
-                [TemplatingStrings.Yes, TemplatingStrings.No],
-                c => c,
-                cancellationToken);
-
-            if (string.Equals(updateChoice, TemplatingStrings.Yes, StringComparisons.CliInputOrOutput))
-            {
-                await NuGetConfigMerger.CreateOrUpdateAsync(workingDir, channel, cancellationToken: cancellationToken);
-                interactionService.DisplayMessage("package", "Updated NuGet.config with required package sources.");
-            }
-        }
-    }
-
-    private static bool TryFindNuGetConfigInDirectory(DirectoryInfo directory, out FileInfo? nugetConfigFile)
-    {
-        ArgumentNullException.ThrowIfNull(directory);
-
-        // Search only the specified directory for a file named "nuget.config", ignoring case
-        nugetConfigFile = directory
-            .EnumerateFiles("*", SearchOption.TopDirectoryOnly)
-            .FirstOrDefault(f => string.Equals(f.Name, "nuget.config", StringComparison.OrdinalIgnoreCase));
-        return nugetConfigFile is not null;
+        // Prompt user before creating or updating NuGet.config
+        await nugetConfigPrompter.PromptToCreateOrUpdateAsync(workingDir, channel, cancellationToken);
     }
 }