feat: exclude projects (#82)

Adds feature to exclude projects to CLI using `--exclude`.

Co-authored-by: xIceFox <xIceFox@users.noreply.github.com>

Author: leonardochaia

README.md

@@ -271,6 +271,39 @@ WRITE: /home/lchaia/dev/dotnet-affected/affected.proj
 WRITE: /home/lchaia/dev/dotnet-affected/affected.json
 ```
 
+## Excluding Projects
+
+Projects can be excluded by using the `--exclude` (shorthand `-e`) argument. It expects a dotnet Regular Expression
+that will be matched against each Project's Full Path.
+
+In the below example, `dotnet-affected.Tests` is excluded due to the regular expression provided.
+```shell
+$ dotnet affected --dry-run --verbose -e .Tests.
+1 files have changed referenced by 1 projects
+0 NuGet Packages have changed
+1 projects are affected by these changes
+1 projects were excluded
+Changed Projects
+Name                        Path                                                                                                    
+dotnet-affected             /home/lchaia/dev/dotnet-affected/src/dotnet-affected/dotnet-affected.csproj                             
+                 
+Affected Projects
+Name                        Path                                                                                                    
+dotnet-affected.Benchmarks  /home/lchaia/dev/dotnet-affected/benchmarks/dotnet-affected.Benchmarks/dotnet-affected.Benchmarks.csproj
+                 
+Excluded Projects
+Name                   Path                                                                                    
+dotnet-affected.Tests  /home/lchaia/dev/dotnet-affected/test/dotnet-affected.Tests/dotnet-affected.Tests.csproj
+DRY-RUN: WRITE /home/lchaia/dev/dotnet-affected/affected.proj
+DRY-RUN: CONTENTS:
+<Project Sdk="Microsoft.Build.Traversal/3.0.3">
+  <ItemGroup>
+    <ProjectReference Include="/home/lchaia/dev/dotnet-affected/benchmarks/dotnet-affected.Benchmarks/dotnet-affected.Benchmarks.csproj" />
+    <ProjectReference Include="/home/lchaia/dev/dotnet-affected/src/dotnet-affected/dotnet-affected.csproj" />
+  </ItemGroup>
+</Project>
+```
+
 ## Continuous Integration
 
 For usage in CI, it's recommended to use the `--from` and `--to` options with the environment variables provided by your

src/DotnetAffected.Abstractions/AffectedSummary.cs

@@ -13,16 +13,19 @@ public class AffectedSummary
         /// <param name="filesThatChanged"></param>
         /// <param name="projectsWithChangedFiles"></param>
         /// <param name="affectedProjects"></param>
+        /// <param name="excludedProjects"></param>
         /// <param name="changedPackages"></param>
         public AffectedSummary(
             string[] filesThatChanged,
             ProjectGraphNode[] projectsWithChangedFiles,
             ProjectGraphNode[] affectedProjects,
+            ProjectGraphNode[] excludedProjects,
             PackageChange[] changedPackages)
         {
             FilesThatChanged = filesThatChanged;
             ProjectsWithChangedFiles = projectsWithChangedFiles;
             AffectedProjects = affectedProjects;
+            ExcludedProjects = excludedProjects;
             ChangedPackages = changedPackages;
         }
 
@@ -41,6 +44,11 @@ public AffectedSummary(
         /// </summary>
         public ProjectGraphNode[] AffectedProjects { get; }
 
+        /// <summary>
+        /// Gets a list of projects that had changes or were affected but were excluded from discovery.
+        /// </summary>
+        public ProjectGraphNode[] ExcludedProjects { get; }
+
         /// <summary>
         /// Gets the list of packages that changed.
         /// </summary>

src/DotnetAffected.Core/AffectedOptions.cs

@@ -16,16 +16,19 @@ public class AffectedOptions : IDiscoveryOptions
         /// <param name="solutionPath"></param>
         /// <param name="fromRef"></param>
         /// <param name="toRef"></param>
+        /// <param name="exclusionRegex"></param>
         public AffectedOptions(
             string? repositoryPath = null,
             string? solutionPath = null,
             string? fromRef = null,
-            string? toRef = null)
+            string? toRef = null,
+            string? exclusionRegex = null)
         {
             RepositoryPath = DetermineRepositoryPath(repositoryPath, solutionPath);
             SolutionPath = solutionPath;
             FromRef = fromRef ?? string.Empty;
             ToRef = toRef ?? string.Empty;
+            ExclusionRegex = exclusionRegex;
         }
 
         /// <summary>
@@ -48,6 +51,11 @@ public AffectedOptions(
         /// </summary>
         public string ToRef { get; }
 
+        /// <summary>
+        /// Gets the regular expression to use for excluding projects.
+        /// </summary>
+        public string? ExclusionRegex { get; }
+
         private static string DetermineRepositoryPath(string? repositoryPath, string? solutionPath)
         {
             // the argument takes precedence.

src/DotnetAffected.Core/Processor/AffectedProcessorBase.cs

@@ -2,6 +2,7 @@
 using Microsoft.Build.Graph;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text.RegularExpressions;
 
 namespace DotnetAffected.Core.Processor
 {
@@ -18,27 +19,41 @@ internal abstract class AffectedProcessorBase
         public AffectedSummary Process(AffectedProcessorContext context)
         {
             // Get files that changed according to changes provider.
-            context.ChangedFiles = DiscoverChangedFiles(context).ToArray();
+            context.ChangedFiles = DiscoverChangedFiles(context)
+                .ToArray();
 
             // Map the files that changed to their corresponding project/s.
-            context.ChangedProjects = DiscoverProjectsForFiles(context).ToArray();
+            var excludedProjects = new List<ProjectGraphNode>();
+            context.ChangedProjects = ApplyExclusionPattern(
+                DiscoverProjectsForFiles(context),
+                context.Options,
+                excludedProjects);
 
             // Get packages that have changed, either from central package management or from the project file
             context.ChangedPackages = DiscoverPackageChanges(context);
 
             // Determine which projects are affected by the projects and packages that have changed.
-            context.AffectedProjects = DiscoverAffectedProjects(context);
+            context.AffectedProjects = ApplyExclusionPattern(
+                DiscoverAffectedProjects(context),
+                context.Options,
+                excludedProjects);
 
             // Output a summary of the operation.
-            return new AffectedSummary(context.ChangedFiles, context.ChangedProjects, context.AffectedProjects, context.ChangedPackages);
+            return new AffectedSummary(
+                context.ChangedFiles,
+                context.ChangedProjects,
+                context.AffectedProjects,
+                excludedProjects.Distinct()
+                    .ToArray(),
+                context.ChangedPackages);
         }
-        
+
         /// <summary>
         /// Discover which files have changes
         /// </summary>
         /// <param name="context"></param>
         /// <returns></returns>
-        protected virtual IEnumerable<string> DiscoverChangedFiles(AffectedProcessorContext context) 
+        protected virtual IEnumerable<string> DiscoverChangedFiles(AffectedProcessorContext context)
             => context.ChangesProvider.GetChangedFiles(context.RepositoryPath, context.FromRef, context.ToRef);
 
         /// <summary>
@@ -49,11 +64,43 @@ protected virtual IEnumerable<string> DiscoverChangedFiles(AffectedProcessorCont
         protected virtual IEnumerable<ProjectGraphNode> DiscoverProjectsForFiles(AffectedProcessorContext context)
         {
             // We init now because we want the graph to initialize late (lazy)
-            var provider = context.ChangedProjectsProvider ?? new PredictionChangedProjectsProvider(context.Graph, context.Options);
+            var provider = context.ChangedProjectsProvider ??
+                           new PredictionChangedProjectsProvider(context.Graph, context.Options);
             // Match which files belong to which of our known projects
             return provider.GetReferencingProjects(context.ChangedFiles);
         }
 
+        /// <summary>
+        /// Applies the <see cref="AffectedOptions.ExclusionRegex"/> to exclude
+        /// projects that matches the regular expression.
+        /// </summary>
+        /// <param name="inputProjects">List of projects that changed.</param>
+        /// <param name="options">Affected options.</param>
+        /// <param name="excludedProjects">Collection of excluded projects</param>
+        /// <returns>Project lis excluding the ones that matches the exclusion regex.</returns>
+        protected virtual ProjectGraphNode[] ApplyExclusionPattern(
+            IEnumerable<ProjectGraphNode> inputProjects,
+            AffectedOptions options,
+            ICollection<ProjectGraphNode> excludedProjects)
+        {
+            var pattern = options.ExclusionRegex;
+
+            if (string.IsNullOrEmpty(pattern))
+                return inputProjects.ToArray();
+
+            var changedProjects = new List<ProjectGraphNode>();
+            var regex = new Regex(pattern);
+            foreach (var project in inputProjects)
+            {
+                if (regex.IsMatch(project.GetFullPath()))
+                    excludedProjects.Add(project);
+                else
+                    changedProjects.Add(project);
+            }
+
+            return changedProjects.ToArray();
+        }
+
         /// <summary>
         /// Discover which packages have changed. <br/>
         /// </summary>

src/dotnet-affected/Commands/AffectedGlobalOptions.cs

@@ -45,6 +45,13 @@ internal static class AffectedGlobalOptions
             description: "A branch or commit to compare against --to.");
 
         public static readonly ToOption ToOption = new(FromOption);
+
+        public static readonly Option<string> ExclusionRegexOption = new(
+            new[]
+            {
+                "--exclude", "-e"
+            },
+            description: "A dotnet Regular Expression used to exclude discovered and affected projects.");
     }
 
     internal sealed class ToOption : Option<string>

src/dotnet-affected/Commands/AffectedRootCommand.cs

@@ -26,6 +26,7 @@ public AffectedRootCommand()
             this.AddGlobalOption(AffectedGlobalOptions.AssumeChangesOption);
             this.AddGlobalOption(AffectedGlobalOptions.FromOption);
             this.AddGlobalOption(AffectedGlobalOptions.ToOption);
+            this.AddGlobalOption(AffectedGlobalOptions.ExclusionRegexOption);
 
             this.AddOption(FormatOption);
             this.AddOption(DryRunOption);
@@ -74,7 +75,7 @@ public FormatOption()
             })
         {
             this.Description = "Space-seperated output file formats. Possible values: <traversal, text, json>.";
-            
+
             this.SetDefaultValue(new[]
             {
                 "traversal"

src/dotnet-affected/Commands/Binding/AffectedOptionsBinder.cs

@@ -15,7 +15,8 @@ protected override AffectedOptions GetBoundValue(BindingContext bindingContext)
                 parseResult.GetValueForOption(AffectedGlobalOptions.RepositoryPathOptions),
                 parseResult.GetValueForOption(AffectedGlobalOptions.SolutionPathOption),
                 parseResult.GetValueForOption(AffectedGlobalOptions.FromOption),
-                parseResult.GetValueForOption(AffectedGlobalOptions.ToOption)
+                parseResult.GetValueForOption(AffectedGlobalOptions.ToOption),
+                parseResult.GetValueForOption(AffectedGlobalOptions.ExclusionRegexOption)
             );
         }
     }

src/dotnet-affected/Views/AffectedInfoView.cs

@@ -12,6 +12,7 @@ public AffectedInfoView(AffectedSummary summary)
                                 $"referenced by {summary.ProjectsWithChangedFiles.Count()} projects"));
             Add(new ContentView($"{summary.ChangedPackages.Count()} NuGet Packages have changed"));
             Add(new ContentView($"{summary.AffectedProjects.Count()} projects are affected by these changes"));
+            Add(new ContentView($"{summary.ExcludedProjects.Count()} projects were excluded"));
 
             Add(new WithChangesAndAffectedView(summary));
         }

src/dotnet-affected/Views/WithChangesAndAffectedView.cs

@@ -29,13 +29,16 @@ public WithChangesAndAffectedView(AffectedSummary summary)
 
             Add(new ContentView("\nAffected Projects"));
 
-            if (!summary.AffectedProjects.Any())
-            {
+            if (summary.AffectedProjects.Any())
+                Add(new ProjectInfoTable(summary.AffectedProjects));
+            else
                 Add(new ContentView("No projects where affected by any of the changed projects."));
-                return;
-            }
 
-            Add(new ProjectInfoTable(summary.AffectedProjects));
+            if (summary.ExcludedProjects.Any())
+            {
+                Add(new ContentView("\nExcluded Projects"));
+                Add(new ProjectInfoTable(summary.ExcludedProjects));
+            }
         }
     }
 }