Add dependency update details to codeflow commits (#4831)

#4697 (comment)

Author: adamzip

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

@@ -2,9 +2,13 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.IO.Hashing;
+using System.Linq;
 using System.Text;
+using Microsoft.DotNet.DarcLib.Models.Darc;
+using Microsoft.VisualStudio.Services.Common;
 
 #nullable enable
 namespace Microsoft.DotNet.DarcLib.Helpers;

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

@@ -4,7 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text.RegularExpressions;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.DotNet.DarcLib.Helpers;
@@ -579,8 +579,13 @@ private async Task<List<DependencyUpdate>> BackflowDependenciesAndToolset(
 
         await targetRepo.StageAsync(["."], cancellationToken);
 
+        string commitMessage = string.Concat(
+            $"Update dependencies from {build.GetRepository()} build {build.Id}",
+            Environment.NewLine,
+            BuildDependencyUpdateCommitMessage(repoChanges));
+
         await targetRepo.CommitAsync(
-            "Update dependencies from " + build.GetRepository() + " build " + build.Id,
+            commitMessage,
             allowEmpty: false,
             cancellationToken: cancellationToken);
 
@@ -666,6 +671,80 @@ private static List<DependencyUpdate> ComputeChanges(Matcher? excludedAssetsMatc
             .ToList();
     }
 
+    public static string BuildDependencyUpdateCommitMessage(IEnumerable<DependencyUpdate> updates)
+    {
+        if (!updates.Any())
+        {
+            return "No dependency updates to commit";
+        }
+        Dictionary<string, List<string>> removedDependencies = new();
+        Dictionary<string, List<string>> addedDependencies = new();
+        Dictionary<string, List<string>> updatedDependencies = new();
+        foreach (DependencyUpdate dependencyUpdate in updates)
+        {
+            if (dependencyUpdate.To != null && dependencyUpdate.From == null)
+            {
+                string versionBlurb = $"Version {dependencyUpdate.To.Version}";
+                AddDependencyToDictionary(addedDependencies, versionBlurb, dependencyUpdate.To.Name);
+                continue;
+            }
+            if (dependencyUpdate.To == null && dependencyUpdate.From != null)
+            {
+                string versionBlurb = $"Version {dependencyUpdate.From.Version}";
+                AddDependencyToDictionary(removedDependencies, versionBlurb, dependencyUpdate.From.Name);
+                continue;
+            }
+            if (dependencyUpdate.To != null && dependencyUpdate.From != null)
+            {
+                string versionBlurb = $"Version {dependencyUpdate.From.Version} -> {dependencyUpdate.To.Version}";
+                AddDependencyToDictionary(updatedDependencies, versionBlurb, dependencyUpdate.From.Name);
+                continue;
+            }
+        }
+
+        var result = new StringBuilder();
+        if (updatedDependencies.Any())
+        {
+            result.AppendLine("Updated Dependencies:");
+            foreach ((string versionBlurb, List<string> packageNames) in updatedDependencies)
+            {
+                result.AppendLine(string.Join(", ", packageNames) + $" ({versionBlurb})");
+            }
+            result.AppendLine();
+        }
+        if (addedDependencies.Any())
+        {
+            result.AppendLine("Added Dependencies:");
+            foreach ((string versionBlurb, List<string> packageNames) in addedDependencies)
+            {
+                result.AppendLine(string.Join(", ", packageNames) + $" ({versionBlurb})");
+            }
+            result.AppendLine();
+        }
+        if (removedDependencies.Any())
+        {
+            result.AppendLine("Removed Dependencies:");
+            foreach ((string versionBlurb, List<string> packageNames) in removedDependencies)
+            {
+                result.AppendLine(string.Join(", ", packageNames) + $" ({versionBlurb})");
+            }
+            result.AppendLine();
+        }
+        return result.ToString().TrimEnd();
+    }
+
+    private static void AddDependencyToDictionary(Dictionary<string, List<string>> dictionary, string versionBlurb, string dependencyName)
+    {
+        if (dictionary.TryGetValue(versionBlurb, out var list))
+        {
+            list.Add(dependencyName);
+        }
+        else
+        {
+            dictionary[versionBlurb] = new List<string> { dependencyName };
+        }
+    }
+
     private async Task<VersionDetails> GetRepoDependencies(ILocalGitRepo repo, string commit)
         => GetDependencies(await repo.GetFileFromGitAsync(VersionFiles.VersionDetailsXml, commit));
 

test/Microsoft.DotNet.DarcLib.Tests/VirtualMonoRepo/VersionFileCodeFlowUpdaterTests.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using FluentAssertions;
@@ -353,6 +354,82 @@ public async Task ConflictingChangesThrowTest()
         await action.Should().ThrowAsync<ConflictingDependencyUpdateException>();
     }
 
+    [Test]
+    public void TestCodeflowDependencyUpdateCommitMessage()
+    {
+        DependencyUpdate dep1 = new()
+        {
+            From = new DependencyDetail()
+            {
+                Name = "Foo",
+                Version = "2.0.0"
+            },
+            To = new DependencyDetail()
+            {
+                Name = "Foo",
+                Version = "3.0.0"
+            },
+        };
+
+        DependencyUpdate dep2 = new()
+        {
+            From = new DependencyDetail()
+            {
+                Name = "Bar",
+                Version = "2.0.0"
+            },
+            To = new DependencyDetail()
+            {
+                Name = "Bar",
+                Version = "3.0.0"
+            },
+        };
+
+        DependencyUpdate dep3 = new()
+        {
+            From = new DependencyDetail()
+            {
+                Name = "Boz",
+                Version = "1.0.0"
+            },
+            To = new DependencyDetail()
+            {
+                Name = "Boz",
+                Version = "4.0.0"
+            },
+        };
+        DependencyUpdate dep4 = new()
+        {
+            To = new DependencyDetail()
+            {
+                Name = "Bop",
+                Version = "3.0.0"
+            },
+        };
+        DependencyUpdate dep5 = new()
+        {
+            From = new DependencyDetail()
+            {
+                Name = "Bam",
+                Version = "2.0.0"
+            },
+        };
+
+        VersionFileCodeFlowUpdater.BuildDependencyUpdateCommitMessage([dep1, dep2, dep3, dep4, dep5]).Should().BeEquivalentTo(
+            """
+            Updated Dependencies:
+            Foo, Bar (Version 2.0.0 -> 3.0.0)
+            Boz (Version 1.0.0 -> 4.0.0)
+
+            Added Dependencies:
+            Bop (Version 3.0.0)
+
+            Removed Dependencies:
+            Bam (Version 2.0.0)
+            """.Trim()
+            );
+
+    }
     private async Task TestConflictResolver(
         Build build,
         Codeflow lastFlow,