Detect NoWarn NU1701 in SDK project discovery and warn during report

nuget/helpers/lib/NuGetUpdater/NuGetUpdater.Core.Test/Utilities/LoggerTests.cs

@@ -4,6 +4,8 @@
 using System.Text;
 using System.Threading.Tasks;
 
+using NuGetUpdater.Core.Discover;
+
 using Xunit;
 using Xunit.Sdk;
 
@@ -56,5 +58,47 @@ public void LogRaw_ShouldStreamLogsIndividually()
         Assert.Contains(testMessage2, output);
     }
 
+    [Fact]
+    public void ReportDiscovery_LogsWarningForProjectsWithNU1701()
+    {
+        var logger = new StringLogger();
+        var discoveryResult = new WorkspaceDiscoveryResult()
+        {
+            Path = "/src",
+            Projects = [
+                new()
+                {
+                    FilePath = "zebra.csproj",
+                    Dependencies = [],
+                    ImportedFiles = [],
+                    AdditionalFiles = [],
+                    HasNoWarnNU1701 = true,
+                },
+                new()
+                {
+                    FilePath = "middle.csproj",
+                    Dependencies = [],
+                    ImportedFiles = [],
+                    AdditionalFiles = [],
+                    HasNoWarnNU1701 = false,
+                },
+                new()
+                {
+                    FilePath = "alpha.csproj",
+                    Dependencies = [],
+                    ImportedFiles = [],
+                    AdditionalFiles = [],
+                    HasNoWarnNU1701 = true,
+                },
+            ]
+        };
+
+        logger.ReportDiscovery(discoveryResult);
 
+        var warnings = logger.Messages.Where(m => m.Contains("has NoWarn property containing NU1701; package compatibility checks may be inaccurate.")).ToList();
+        Assert.Equal(2, warnings.Count);
+        Assert.Contains("/src/alpha.csproj", warnings[0]);
+        Assert.Contains("/src/zebra.csproj", warnings[1]);
+        Assert.DoesNotContain(logger.Messages, m => m.Contains("Project [/src/middle.csproj] has NoWarn property containing NU1701; package compatibility checks may be inaccurate."));
+    }
 }

nuget/helpers/lib/NuGetUpdater/NuGetUpdater.Core/Discover/ProjectDiscoveryResult.cs

@@ -16,4 +16,5 @@ public record ProjectDiscoveryResult : IDiscoveryResultWithDependencies
     public required ImmutableArray<string> ImportedFiles { get; init; }
     public required ImmutableArray<string> AdditionalFiles { get; init; }
     public required ImmutableArray<Dependency> Dependencies { get; init; }
+    public bool HasNoWarnNU1701 { get; init; } = false;
 }

nuget/helpers/lib/NuGetUpdater/NuGetUpdater.Core/Discover/SdkProjectDiscovery.cs

@@ -674,6 +674,18 @@ PackageManagementKind.CentralPackageManagement or
                 packageManagementKind = PackageManagementKind.Default;
             }
 
+            // check for NoWarn containing NU1701
+            var noWarnValue = GetStringPropertyFromProjectProperties(projectProperties, "NoWarn");
+            var hasNoWarnNU1701 = false;
+            if (noWarnValue is not null)
+            {
+                var noWarnCodes = noWarnValue.Split(';', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                if (noWarnCodes.Contains("NU1701", StringComparer.OrdinalIgnoreCase))
+                {
+                    hasNoWarnNU1701 = true;
+                }
+            }
+
             var projectDiscoveryResult = new ProjectDiscoveryResult()
             {
                 FilePath = projectRelativePath,
@@ -684,6 +696,7 @@ PackageManagementKind.CentralPackageManagement or
                 AdditionalFiles = additional,
                 PackageManagementKind = packageManagementKind,
                 PackageManagementSpecialFileRelativePath = packageManagementFile,
+                HasNoWarnNU1701 = hasNoWarnNU1701,
             };
             projectDiscoveryResults.Add(projectDiscoveryResult);
         }

nuget/helpers/lib/NuGetUpdater/NuGetUpdater.Core/Utilities/ILogger.cs

@@ -24,6 +24,16 @@ public static void ReportAnalysis(this ILogger logger, AnalysisResult analysisRe
 
     public static void ReportDiscovery(this ILogger logger, WorkspaceDiscoveryResult discoveryResult)
     {
+        var nu1701Projects = discoveryResult.Projects
+            .Where(p => p.HasNoWarnNU1701)
+            .Select(p => PathHelper.JoinPath(discoveryResult.Path, p.FilePath).FullyNormalizedRootedPath())
+            .OrderBy(p => p, StringComparer.OrdinalIgnoreCase)
+            .ToList();
+        foreach (var projectPath in nu1701Projects)
+        {
+            logger.Warn($"Project [{projectPath}] has NoWarn property containing NU1701; package compatibility checks may be inaccurate.");
+        }
+
         logger.Info("Discovery JSON content:");
         logger.Info(JsonSerializer.Serialize(discoveryResult, DiscoveryWorker.SerializerOptions));
     }