Added --use-project-assets-json (#82)

README.md

@@ -45,6 +45,7 @@ Usage: dotnet-project-licenses [options]
 | `--help` | Display this help screen. |
 | `--version` | Display version information. |
 | `--ignore-ssl-certificate-errors` | Ignores SSL certificate errors in HttpClient. |
+| `--use-project-assets-json` | Use the resolved project.assets.json file for each project as the source of package information. Requires the `-t` option since this always includes transitive references. Requires `nuget restore` or `dotnet restore` to be run first. |
 
 ## Example tool commands
 

src/Methods.cs

@@ -5,6 +5,7 @@
 using System.Linq;
 using System.Net.Http;
 using System.Text;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Xml.Linq;
@@ -277,8 +278,27 @@ public IEnumerable<string> GetProjectReferences(string projectPath)
                 throw new FileNotFoundException();
             }
 
-            // First try to get references from new project file format
-            var references = GetProjectReferencesFromNewProjectFile(projectPath);
+            IEnumerable<string> references = Array.Empty<string>();
+
+            // First use project.assets.json, if this option is enabled.
+            if (_packageOptions.UseProjectAssetsJson)
+            {
+                var assetsFile = Path.Combine(Path.GetDirectoryName(projectPath) ?? ".", "obj", "project.assets.json");
+                if (!File.Exists(assetsFile))
+                {
+                    WriteOutput(() => $"Cannot find {assetsFile}", logLevel: LogLevel.Warning);
+                }
+                else
+                {
+                    references = GetProjectReferencesFromAssetsFile(assetsFile);
+                }
+            }
+
+            // Then try to get references from new project file format
+            if (!references.Any())
+            {
+                references = GetProjectReferencesFromNewProjectFile(projectPath);
+            }
 
             // Then if needed from old packages.config
             if (!references.Any())
@@ -617,6 +637,41 @@ private IEnumerable<string> GetProjectReferencesFromPackagesConfig(string projec
             return Array.Empty<string>();
         }
 
+        /// <summary>
+        /// Gets project references from a project.assets.json file.
+        /// </summary>
+        /// <param name="assetsPath">The assets file</param>
+        /// <returns></returns>
+        private IEnumerable<string> GetProjectReferencesFromAssetsFile(string assetsPath)
+        {
+            WriteOutput(() => $"Reading assets file {assetsPath}", logLevel: LogLevel.Verbose);
+            using var assetsFileStream = File.OpenRead(assetsPath);
+            var doc = JsonDocument.Parse(assetsFileStream);
+            assetsFileStream.Dispose();
+
+            if (!doc.RootElement.TryGetProperty("targets", out var targets))
+            {
+                WriteOutput(() => $"No \"targets\" property found in {assetsPath}", logLevel: LogLevel.Warning);
+                yield break;
+            }
+
+            foreach (var target in targets.EnumerateObject())
+            {
+                WriteOutput(() => $"Reading dependencies for target {target.Name}", logLevel: LogLevel.Verbose);
+                foreach (var dep in target.Value.EnumerateObject())
+                {
+                    var depName = dep.Name.Split('/');
+                    if (depName.Length != 2)
+                    {
+                        WriteOutput(() => $"Unexpected package name: {dep.Name}", logLevel: LogLevel.Warning);
+                        continue;
+                    }
+
+                    yield return string.Join(",", depName);
+                }
+            }
+        }
+
         private async Task<IEnumerable<string>> GetValidProjects(string projectPath)
         {
             var pathInfo = new FileInfo(projectPath);

src/PackageOptions.cs

@@ -70,6 +70,9 @@ public class PackageOptions
         [Option("ignore-ssl-certificate-errors", Default = false, HelpText = "Ignore SSL certificate errors in HttpClient.")]
         public bool IgnoreSslCertificateErrors { get; set; }
 
+        [Option("use-project-assets-json", Default = false, HelpText = "Use the resolved project.assets.json file for each project as the source of package information. Requires the -t option. Requires `nuget restore` or `dotnet restore` to be run first.")]
+        public bool UseProjectAssetsJson { get; set; }
+
         [Usage(ApplicationAlias = "dotnet-project-licenses")]
         public static IEnumerable<Example> Examples
         {

src/Program.cs

@@ -25,6 +25,14 @@ private static async Task<int> Execute(PackageOptions options)
                 return 1;
             }
 
+            if (options.UseProjectAssetsJson && !options.IncludeTransitive)
+            {
+                Console.WriteLine("ERROR(S):");
+                Console.WriteLine("--use-project-assets-json\tThis option always includes transitive references, so you must also provide the -t option.");
+
+                return 1;
+            }
+
             try
             {
                 Methods methods = new Methods(options);

tests/NugetUtility.Tests/MethodsTests.cs

@@ -2,7 +2,9 @@
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using System.Threading.Tasks;
+using CommandLine.Text;
 using FluentAssertions;
 using NUnit.Framework;
 
@@ -185,6 +187,32 @@ public async Task GetPackages_InputJson_Should_OnlyParseGivenProjects () {
             validationResult.InvalidPackages.Count.Should ().Be (3);
         }
 
+        [Test]
+        public async Task GetProjectReferencesFromAssetsFile_Should_Resolve_Transitive_Assets()
+        {
+            var methods = new Methods(new PackageOptions
+            {
+                UseProjectAssetsJson = true,
+                IncludeTransitive = true,
+                ProjectDirectory = @"../../../",
+            });
+
+            var packages = await methods.GetPackages();
+            packages.Should().ContainKey("../../../NugetUtility.Tests.csproj");
+            packages.Should().HaveCount(1);
+            var list = packages.Values.First();
+
+            // Just look for a few expected packages. First-order refs:
+            list.Should().ContainKey($"dotnet-project-licenses,{typeof(Methods).Assembly.GetName().Version.ToString(3)}");
+            list.Should().ContainKey($"NUnit,{typeof(TestAttribute).Assembly.GetName().Version.ToString(3)}");
+
+            // Some second-order refs:
+            list.Should().ContainKey($"CommandLineParser,{typeof(UsageAttribute).Assembly.GetName().Version.ToString(3)}");
+            list.Should().ContainKey("System.IO.Compression,4.3.0");
+
+            // Some third-order refs:
+            list.Should().ContainKey("System.Buffers,4.3.0");
+        }
 
         [TestCase("BenchmarkDotNet", "0.12.1", "https://licenses.nuget.org/MIT", "MIT")]
         [TestCase("BCrypt.Net-Next", "2.1.3", "https://github.com/BcryptNet/bcrypt.net/blob/master/licence.txt", "")]