Allow targeting a specific branch in VMR code flow (#3331)

src/Microsoft.DotNet.Darc/DarcLib/Helpers/GitRepoUrlParser.cs

@@ -2,7 +2,10 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Collections;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 
 #nullable enable
 namespace Microsoft.DotNet.DarcLib.Helpers;
@@ -63,6 +66,9 @@ public static int OrderByLocalPublicOther(GitRepoType first, GitRepoType second)
         return 1;
     }
 
+    public static IEnumerable<string> OrderRemotesByLocalPublicOther(this IEnumerable<string> uris)
+        => uris.OrderBy(ParseTypeFromUri, Comparer<GitRepoType>.Create(OrderByLocalPublicOther));
+
     public static (string RepoName, string Org) GetRepoNameAndOwner(string uri)
     {
         var repoType = ParseTypeFromUri(uri);

src/Microsoft.DotNet.Darc/DarcLib/Models/VirtualMonoRepo/SourceManifest.cs

@@ -1,12 +1,13 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using Microsoft.DotNet.DarcLib.VirtualMonoRepo;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using System.Text.Json;
+using Microsoft.DotNet.DarcLib.VirtualMonoRepo;
 
 #nullable enable
 namespace Microsoft.DotNet.Darc.Models.VirtualMonoRepo;
@@ -22,6 +23,8 @@ public interface ISourceManifest
     void UpdateSubmodule(SubmoduleRecord submodule);
     void UpdateVersion(string repository, string uri, string sha, string? packageVersion);
     VmrDependencyVersion? GetVersion(string repository);
+    bool TryGetRepoVersion(string mappingName, [NotNullWhen(true)] out ISourceComponent? mapping);
+    ISourceComponent GetRepoVersion(string mappingName);
     void Refresh(string sourceManifestPath);
 }
 
@@ -122,11 +125,23 @@ public void Refresh(string sourceManifestPath)
         _submodules = newManifst._submodules;
     }
 
+    public bool TryGetRepoVersion(string mappingName, [NotNullWhen(true)] out ISourceComponent? version)
+    {
+        version = Repositories.FirstOrDefault(m => m.Path.Equals(mappingName, StringComparison.InvariantCultureIgnoreCase));
+        version ??= Submodules.FirstOrDefault(m => m.Path.Equals(mappingName, StringComparison.InvariantCultureIgnoreCase));
+        return version != null;
+    }
+
+    public ISourceComponent GetRepoVersion(string mappingName)
+        => TryGetRepoVersion(mappingName, out var version)
+            ? version
+            : throw new Exception($"No manifest record named {mappingName} found");
+
     public static SourceManifest FromJson(string path)
     {
         if (!File.Exists(path))
         {
-            return new SourceManifest(Array.Empty<RepositoryRecord>(), Array.Empty<SubmoduleRecord>());
+            return new SourceManifest([], []);
         }
 
         var options = new JsonSerializerOptions
@@ -149,7 +164,7 @@ public static SourceManifest FromJson(string path)
         if (repositoryRecord != null)
         {
             return new(repositoryRecord.CommitSha, repositoryRecord.PackageVersion);
-        } 
+        }
         else
         {
             return null;
@@ -161,7 +176,7 @@ public static SourceManifest FromJson(string path)
     /// </summary>
     private class SourceManifestWrapper
     {
-        public ICollection<RepositoryRecord> Repositories { get; init; } = Array.Empty<RepositoryRecord>();
-        public ICollection<SubmoduleRecord> Submodules { get; init; } = Array.Empty<SubmoduleRecord>();
+        public ICollection<RepositoryRecord> Repositories { get; init; } = [];
+        public ICollection<SubmoduleRecord> Submodules { get; init; } = [];
     }
 }

src/Microsoft.DotNet.Darc/DarcLib/VirtualMonoRepo/VmrBackflower.cs

@@ -16,6 +16,17 @@ namespace Microsoft.DotNet.DarcLib.VirtualMonoRepo;
 
 public interface IVmrBackFlower
 {
+    /// <summary>
+    /// Flows backward the code from the VMR to the target branch of a product repo.
+    /// This overload is used in the context of the darc CLI.
+    /// </summary>
+    /// <param name="mapping">Mapping to flow</param>
+    /// <param name="targetRepo">Local checkout of the repository</param>
+    /// <param name="shaToFlow">SHA to flow</param>
+    /// <param name="buildToFlow">Build to flow</param>
+    /// <param name="branchName">New branch name</param>
+    /// <param name="targetBranch">Target branch to create the PR branch on top of</param>
+    /// <param name="discardPatches">Keep patch files?</param>
     Task<bool> FlowBackAsync(
         string mapping,
         NativePath targetRepo,
@@ -25,6 +36,17 @@ Task<bool> FlowBackAsync(
         bool discardPatches = false,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    /// Flows backward the code from the VMR to the target branch of a product repo.
+    /// This overload is used in the context of the darc CLI.
+    /// </summary>
+    /// <param name="mapping">Mapping to flow</param>
+    /// <param name="targetRepo">Local checkout of the repository</param>
+    /// <param name="shaToFlow">SHA to flow</param>
+    /// <param name="buildToFlow">Build to flow</param>
+    /// <param name="branchName">New branch name</param>
+    /// <param name="targetBranch">Target branch to create the PR branch on top of</param>
+    /// <param name="discardPatches">Keep patch files?</param>
     Task<bool> FlowBackAsync(
         string mapping,
         ILocalGitRepo targetRepo,
@@ -33,26 +55,30 @@ Task<bool> FlowBackAsync(
         string? branchName,
         bool discardPatches = false,
         CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Flows backward the code from the VMR to the target branch of a product repo.
+    /// This overload is used in the context of the PCS.
+    /// </summary>
+    /// <param name="mappingName">Mapping to flow</param>
+    /// <param name="build">Build to flow</param>
+    /// <param name="branchName">New branch name</param>
+    /// <param name="targetBranch">Target branch to create the PR branch on top of</param>
+    /// <returns>True when there were changes to be flown</returns>
+    Task<bool> FlowBackAsync(
+        string mappingName,
+        Build build,
+        string branchName,
+        string targetBranch,
+        CancellationToken cancellationToken = default);
 }
 
-internal class VmrBackFlower : VmrCodeFlower, IVmrBackFlower
-{
-    private readonly IVmrInfo _vmrInfo;
-    private readonly ISourceManifest _sourceManifest;
-    private readonly IVmrDependencyTracker _dependencyTracker;
-    private readonly ILocalGitClient _localGitClient;
-    private readonly ILocalGitRepoFactory _localGitRepoFactory;
-    private readonly IVmrPatchHandler _vmrPatchHandler;
-    private readonly IWorkBranchFactory _workBranchFactory;
-    private readonly IBasicBarClient _barClient;
-    private readonly IFileSystem _fileSystem;
-    private readonly ILogger<VmrCodeFlower> _logger;
-
-    public VmrBackFlower(
+internal class VmrBackFlower(
         IVmrInfo vmrInfo,
         ISourceManifest sourceManifest,
         IVmrDependencyTracker dependencyTracker,
         IDependencyFileManager dependencyFileManager,
+        IRepositoryCloneManager repositoryCloneManager,
         ILocalGitClient localGitClient,
         ILocalGitRepoFactory localGitRepoFactory,
         IVersionDetailsParser versionDetailsParser,
@@ -64,31 +90,19 @@ public VmrBackFlower(
         IAssetLocationResolver assetLocationResolver,
         IFileSystem fileSystem,
         ILogger<VmrCodeFlower> logger)
-        : base(
-            vmrInfo,
-            sourceManifest,
-            dependencyTracker,
-            localGitClient,
-            libGit2Client,
-            localGitRepoFactory,
-            versionDetailsParser,
-            dependencyFileManager,
-            coherencyUpdateResolver,
-            assetLocationResolver,
-            fileSystem,
-            logger)
-    {
-        _vmrInfo = vmrInfo;
-        _sourceManifest = sourceManifest;
-        _dependencyTracker = dependencyTracker;
-        _localGitClient = localGitClient;
-        _localGitRepoFactory = localGitRepoFactory;
-        _vmrPatchHandler = vmrPatchHandler;
-        _workBranchFactory = workBranchFactory;
-        _barClient = basicBarClient;
-        _fileSystem = fileSystem;
-        _logger = logger;
-    }
+    : VmrCodeFlower(vmrInfo, sourceManifest, dependencyTracker, repositoryCloneManager, localGitClient, libGit2Client, localGitRepoFactory, versionDetailsParser, dependencyFileManager, coherencyUpdateResolver, assetLocationResolver, fileSystem, logger),
+    IVmrBackFlower
+{
+    private readonly IVmrInfo _vmrInfo = vmrInfo;
+    private readonly ISourceManifest _sourceManifest = sourceManifest;
+    private readonly IVmrDependencyTracker _dependencyTracker = dependencyTracker;
+    private readonly ILocalGitClient _localGitClient = localGitClient;
+    private readonly ILocalGitRepoFactory _localGitRepoFactory = localGitRepoFactory;
+    private readonly IVmrPatchHandler _vmrPatchHandler = vmrPatchHandler;
+    private readonly IWorkBranchFactory _workBranchFactory = workBranchFactory;
+    private readonly IBasicBarClient _barClient = basicBarClient;
+    private readonly IFileSystem _fileSystem = fileSystem;
+    private readonly ILogger<VmrCodeFlower> _logger = logger;
 
     public Task<bool> FlowBackAsync(
         string mapping,
@@ -98,7 +112,36 @@ public Task<bool> FlowBackAsync(
         string? branchName,
         bool discardPatches = false,
         CancellationToken cancellationToken = default)
-        => FlowBackAsync(mapping, _localGitRepoFactory.Create(targetRepoPath), shaToFlow, buildToFlow, branchName, discardPatches, cancellationToken);
+        => FlowBackAsync(
+            mapping,
+            _localGitRepoFactory.Create(targetRepoPath),
+            shaToFlow,
+            buildToFlow,
+            branchName,
+            discardPatches,
+            cancellationToken);
+
+    public async Task<bool> FlowBackAsync(
+        string mappingName,
+        Build build,
+        string branchName,
+        string targetBranch,
+        CancellationToken cancellationToken = default)
+    {
+        SourceMapping mapping = _dependencyTracker.GetMapping(mappingName);
+        ILocalGitRepo targetRepo = await PrepareRepoAndVmr(mapping, targetBranch, build.Commit, cancellationToken);
+        Codeflow lastFlow = await GetLastFlowAsync(mapping, targetRepo, currentIsBackflow: true);
+
+        return await FlowBackAsync(
+            mapping,
+            targetRepo,
+            lastFlow,
+            build.Commit,
+            build,
+            branchName,
+            true,
+            cancellationToken);
+    }
 
     public async Task<bool> FlowBackAsync(
         string mappingName,
@@ -127,9 +170,29 @@ public async Task<bool> FlowBackAsync(
             await CheckOutVmr(shaToFlow);
         }
 
-        var mapping = _dependencyTracker.Mappings.First(m => m.Name == mappingName);
+        var mapping = _dependencyTracker.GetMapping(mappingName);
         Codeflow lastFlow = await GetLastFlowAsync(mapping, targetRepo, currentIsBackflow: true);
+        return await FlowBackAsync(
+            mapping,
+            targetRepo,
+            lastFlow,
+            shaToFlow,
+            build,
+            branchName,
+            discardPatches,
+            cancellationToken);
+    }
 
+    private async Task<bool> FlowBackAsync(
+        SourceMapping mapping,
+        ILocalGitRepo targetRepo,
+        Codeflow lastFlow,
+        string shaToFlow,
+        Build? build,
+        string? branchName,
+        bool discardPatches,
+        CancellationToken cancellationToken)
+    {
         var hasChanges = await FlowCodeAsync(
             lastFlow,
             new Backflow(lastFlow.TargetSha, shaToFlow),

src/Microsoft.DotNet.Darc/DarcLib/VirtualMonoRepo/VmrCodeflower.cs

@@ -26,6 +26,7 @@ internal abstract class VmrCodeFlower
     private readonly IVmrInfo _vmrInfo;
     private readonly ISourceManifest _sourceManifest;
     private readonly IVmrDependencyTracker _dependencyTracker;
+    private readonly IRepositoryCloneManager _repositoryCloneManager;
     private readonly ILocalGitClient _localGitClient;
     private readonly ILocalLibGit2Client _libGit2Client;
     private readonly IVersionDetailsParser _versionDetailsParser;
@@ -41,6 +42,7 @@ protected VmrCodeFlower(
         IVmrInfo vmrInfo,
         ISourceManifest sourceManifest,
         IVmrDependencyTracker dependencyTracker,
+        IRepositoryCloneManager repositoryCloneManager,
         ILocalGitClient localGitClient,
         ILocalLibGit2Client libGit2Client,
         ILocalGitRepoFactory localGitRepoFactory,
@@ -54,6 +56,7 @@ protected VmrCodeFlower(
         _vmrInfo = vmrInfo;
         _sourceManifest = sourceManifest;
         _dependencyTracker = dependencyTracker;
+        _repositoryCloneManager = repositoryCloneManager;
         _localGitClient = localGitClient;
         _libGit2Client = libGit2Client;
         _versionDetailsParser = versionDetailsParser;
@@ -99,12 +102,28 @@ protected async Task<bool> FlowCodeAsync(
         if (lastFlow.Name == currentFlow.Name)
         {
             _logger.LogInformation("Current flow is in the same direction");
-            hasChanges = await SameDirectionFlowAsync(mapping, lastFlow, currentFlow, repo, build, branchName, discardPatches, cancellationToken);
+            hasChanges = await SameDirectionFlowAsync(
+                mapping,
+                lastFlow,
+                currentFlow,
+                repo,
+                build,
+                branchName,
+                discardPatches,
+                cancellationToken);
         }
         else
         {
             _logger.LogInformation("Current flow is in the opposite direction");
-            hasChanges = await OppositeDirectionFlowAsync(mapping, lastFlow, currentFlow, repo, build, branchName, discardPatches, cancellationToken);
+            hasChanges = await OppositeDirectionFlowAsync(
+                mapping,
+                lastFlow,
+                currentFlow,
+                repo,
+                build,
+                branchName,
+                discardPatches,
+                cancellationToken);
         }
 
         if (!hasChanges)
@@ -259,8 +278,7 @@ protected async Task<Codeflow> GetLastFlowAsync(SourceMapping mapping, ILocalGit
     /// </summary>
     private async Task<ForwardFlow> GetLastForwardFlow(string mappingName)
     {
-        IVersionedSourceComponent repoInVmr = _sourceManifest.Repositories.FirstOrDefault(r => r.Path == mappingName)
-            ?? throw new ArgumentException($"No repository mapping named {mappingName} found");
+        ISourceComponent repoInVmr = _sourceManifest.GetRepoVersion(mappingName);
 
         // Last forward flow SHAs come from source-manifest.json in the VMR
         string lastForwardRepoSha = repoInVmr.CommitSha;
@@ -356,6 +374,26 @@ protected async Task UpdateDependenciesAndToolset(
         await targetRepo.CommitAsync($"Update dependency files to {currentVmrSha}", allowEmpty: true, cancellationToken: cancellationToken);
     }
 
+    protected async Task<ILocalGitRepo> PrepareRepoAndVmr(
+        SourceMapping mapping,
+        string repoRef,
+        string vmrRef,
+        CancellationToken cancellationToken)
+    {
+        var remotes = new[] { mapping.DefaultRef, _sourceManifest.GetRepoVersion(mapping.Name).RemoteUri }
+            .Distinct()
+            .OrderRemotesByLocalPublicOther();
+
+        ILocalGitRepo repo = await _repositoryCloneManager.PrepareCloneAsync(
+            mapping,
+            [.. remotes],
+            repoRef,
+            cancellationToken);
+
+        await CheckOutVmr(vmrRef);
+        return repo;
+    }
+
     /// <summary>
     /// Compares 2 git commits and returns true if the first one is an ancestor of the second one.
     /// </summary>