Auto approve API

src/GraphQLParser.ApiTests/ApiApprovalTests.cs

@@ -1,4 +1,9 @@
 using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Xml.Linq;
 using PublicApiGenerator;
 using Shouldly;
 using Xunit;
@@ -14,18 +19,65 @@ public class ApiApprovalTests
         [InlineData(typeof(Lexer))]
         public void Public_Api_Should_Not_Change_Inadvertently(Type type)
         {
-            string publicApi = type.Assembly.GeneratePublicApi(new ApiGeneratorOptions
+            string baseDir = AppDomain.CurrentDomain.BaseDirectory;
+            string projectName = type.Assembly.GetName().Name!;
+            string testDir = Path.Combine(baseDir, $"..{Path.DirectorySeparatorChar}..{Path.DirectorySeparatorChar}..");
+            string projectDir = Path.Combine(testDir, "..");
+            string buildDir = Path.Combine(projectDir, projectName, "bin", "Debug");
+            Debug.Assert(Directory.Exists(buildDir), $"Directory '{buildDir}' doesn't exist");
+            string csProject = Path.Combine(projectDir, projectName, projectName + ".csproj");
+            var project = XDocument.Load(csProject);
+            string[] tfms = project.Descendants("TargetFrameworks").Union(project.Descendants("TargetFramework")).First().Value.Split(";", StringSplitOptions.RemoveEmptyEntries);
+
+            // There may be old stuff from earlier builds like net45, netcoreapp3.0, etc. so filter it out
+            string[] actualTfmDirs = Directory.GetDirectories(buildDir).Where(dir => tfms.Any(tfm => dir.EndsWith(tfm))).ToArray();
+            Debug.Assert(actualTfmDirs.Length > 0, $"Directory '{buildDir}' doesn't contain subdirectories matching {string.Join(";", tfms)}");
+
+            (string tfm, string content)[] publicApi = actualTfmDirs.Select(tfmDir => (new DirectoryInfo(tfmDir).Name.Replace(".", ""), Assembly.LoadFile(Path.Combine(tfmDir, projectName + ".dll")).GeneratePublicApi(new ApiGeneratorOptions
             {
                 IncludeAssemblyAttributes = false,
                 //WhitelistedNamespacePrefixes = new[] { "Microsoft.Extensions.DependencyInjection" },
-                ExcludeAttributes = new[] { "System.Diagnostics.DebuggerDisplayAttribute" }
-            });
+                ExcludeAttributes = new[] { "System.Diagnostics.DebuggerDisplayAttribute", "System.Diagnostics.CodeAnalysis.AllowNullAttribute" }
+            }))).ToArray();
+
+            if (publicApi.DistinctBy(item => item.content).Count() == 1)
+            {
+                AutoApproveOrFail(publicApi[0].content, "");
+            }
+            else
+            {
+                foreach (var item in publicApi.ToLookup(item => item.content))
+                {
+                    AutoApproveOrFail(item.Key, string.Join("+", item.Select(x => x.tfm).OrderBy(x => x)));
+                }
+            }
+
+            // Approval test should (re)generate approved.txt files locally if needed.
+            // Approval test should fail on CI.
+            // https://docs.github.com/en/actions/learn-github-actions/environment-variables#default-environment-variables
+            void AutoApproveOrFail(string publicApi, string folder)
+            {
+                string file = null!;
 
-            // See: https://shouldly.readthedocs.io/en/latest/assertions/shouldMatchApproved.html
-            // Note: If the AssemblyName.approved.txt file doesn't match the latest publicApi value,
-            // this call will try to launch a diff tool to help you out but that can fail on
-            // your machine if a diff tool isn't configured/setup.
-            publicApi.ShouldMatchApproved(options => options.WithFilenameGenerator((testMethodInfo, discriminator, fileType, fileExtension) => $"{type.Assembly.GetName().Name}.{fileType}.{fileExtension}"));
+                try
+                {
+                    publicApi.ShouldMatchApproved(options => options.SubFolder(folder).NoDiff().WithFilenameGenerator((testMethodInfo, discriminator, fileType, fileExtension) => file = $"{type.Assembly.GetName().Name}.{fileType}.{fileExtension}"));
+                }
+                catch (ShouldMatchApprovedException) when (Environment.GetEnvironmentVariable("CI") == null)
+                {
+                    string? received = Path.Combine(testDir, folder, file);
+                    string? approved = received.Replace(".received.txt", ".approved.txt");
+                    if (File.Exists(received) && File.Exists(approved))
+                    {
+                        File.Copy(received, approved, overwrite: true);
+                        File.Delete(received);
+                    }
+                    else
+                    {
+                        throw;
+                    }
+                }
+            }
         }
     }
 }

src/GraphQLParser.ApiTests/GraphQLParser.ApiTests.csproj

@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFramework>net6</TargetFramework>
     <NoWarn>$(NoWarn);1591</NoWarn>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

src/GraphQLParser/GraphQLParser.csproj

@@ -5,7 +5,6 @@
     <Product>GraphQL Parser</Product>
     <AssemblyTitle>GraphQL Parser for .NET</AssemblyTitle>
     <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
-    <AssemblyName>GraphQL-Parser</AssemblyName>
     <PackageTags>GraphQL;json;api;parser</PackageTags>
   </PropertyGroup>