Scope RT0006 error to current compilation only (#19)

Author: olstakh

src/Analyzers/ReferenceProtector.Analyzers.Tests/ReferenceProtectorAnalyzerTests.cs

@@ -414,6 +414,54 @@ TestProject.csproj	PackageReferenceDirect	SomeOtherPackage
         await test.RunAsync(TestContext.Current.CancellationToken);
     }
 
+    /// <summary>
+    /// Verifies that a tech debt exception whose From does not match the current project does NOT trigger RP0006.
+    /// This covers the case where a broad rule (From: *) has exceptions for other projects that aren't part
+    /// of the current compilation — declared references only contain references for the current project.
+    /// </summary>
+    [Fact]
+    public async Task TechDebtException_ForDifferentProject_ShouldNotReportDiagnostic_Async()
+    {
+        var test = GetAnalyzer();
+        test.TestState.AdditionalFiles.Add(
+            ("DependencyRules.json", """
+            {
+                "ProjectDependencies": [
+                    {
+                        "From": "*",
+                        "To": "*",
+                        "Description": "No direct project references allowed",
+                        "Policy": "Forbidden",
+                        "LinkType": "Direct",
+                        "Exceptions": [
+                            {
+                                "From": "TestProject.csproj",
+                                "To": "ReferencedProject.csproj",
+                                "Justification": "Tech debt for TestProject",
+                                "IsTechDebt": true
+                            },
+                            {
+                                "From": "OtherProject.csproj",
+                                "To": "SomeLib.csproj",
+                                "Justification": "Tech debt for OtherProject",
+                                "IsTechDebt": true
+                            }
+                        ]
+                    }
+                ]
+            }
+            """));
+
+        test.TestState.AdditionalFiles.Add(
+            (ReferenceProtectorAnalyzer.DeclaredReferencesFile, """
+            TestProject.csproj	ProjectReferenceDirect	ReferencedProject.csproj
+            """));
+
+        // TestProject→ReferencedProject is covered by the first exception (still needed), so no RP0004 or RP0006.
+        // The second exception (OtherProject→SomeLib) is for a different project — should NOT trigger RP0006.
+        await test.RunAsync(TestContext.Current.CancellationToken);
+    }
+
     /// <summary>
     /// Verifies IsTechDebt defaults to false when not specified in JSON.
     /// </summary>

src/Analyzers/ReferenceProtector.Analyzers/ReferenceProtector.Analyzers.cs

@@ -152,7 +152,7 @@ private void AnalyzeDependencyRules(CompilationAnalysisContext context)
             }
 
             AnalyzeDeclaredProjectReferences(context, declaredReferences.ToImmutableArray(), thisProjectDependencyRules.ToImmutableArray(), Descriptors.ProjectReferenceViolation, dependencyRulesFile.Path);
-            ReportStaleTechDebtProjectExceptions(context, declaredReferences.ToImmutableArray(), thisProjectDependencyRules.ToImmutableArray(), dependencyRulesFile.Path);
+            ReportStaleTechDebtProjectExceptions(context, declaredReferences.ToImmutableArray(), thisProjectDependencyRules.ToImmutableArray(), dependencyRulesFile.Path, projectPath);
         }
 
         // Analyze package dependencies
@@ -165,7 +165,7 @@ private void AnalyzeDependencyRules(CompilationAnalysisContext context)
                 .Where(r => r.LinkType == ReferenceKind.PackageReferenceDirect);
 
             AnalyzeDeclaredPackageReferences(context, packageReferences.ToImmutableArray(), thisPackageDependencyRules.ToImmutableArray(), Descriptors.PackageReferenceViolation, dependencyRulesFile.Path);
-            ReportStaleTechDebtPackageExceptions(context, packageReferences.ToImmutableArray(), thisPackageDependencyRules.ToImmutableArray(), dependencyRulesFile.Path);
+            ReportStaleTechDebtPackageExceptions(context, packageReferences.ToImmutableArray(), thisPackageDependencyRules.ToImmutableArray(), dependencyRulesFile.Path, projectPath);
         }
     }
 
@@ -259,7 +259,8 @@ private void ReportStaleTechDebtProjectExceptions(
         CompilationAnalysisContext context,
         ImmutableArray<ReferenceItem> declaredReferences,
         ImmutableArray<ProjectDependency> dependencyRules,
-        string dependencyRulesFile)
+        string dependencyRulesFile,
+        string projectPath)
     {
         foreach (var rule in dependencyRules)
         {
@@ -271,6 +272,11 @@ private void ReportStaleTechDebtProjectExceptions(
                 if (!exception.IsTechDebt)
                     continue;
 
+                // Only evaluate exceptions whose From matches the current project,
+                // since declared references only contain references for this compilation.
+                if (!IsMatchByName(exception.From, projectPath))
+                    continue;
+
                 var exceptionStillNeeded = declaredReferences.Any(reference =>
                     IsMatchByName(exception.From, reference.Source) &&
                     IsMatchByName(exception.To, reference.Target) &&
@@ -295,7 +301,8 @@ private void ReportStaleTechDebtPackageExceptions(
         CompilationAnalysisContext context,
         ImmutableArray<ReferenceItem> declaredReferences,
         ImmutableArray<PackageDependency> dependencyRules,
-        string dependencyRulesFile)
+        string dependencyRulesFile,
+        string projectPath)
     {
         foreach (var rule in dependencyRules)
         {
@@ -307,6 +314,11 @@ private void ReportStaleTechDebtPackageExceptions(
                 if (!exception.IsTechDebt)
                     continue;
 
+                // Only evaluate exceptions whose From matches the current project,
+                // since declared references only contain references for this compilation.
+                if (!IsMatchByName(exception.From, projectPath))
+                    continue;
+
                 var exceptionStillNeeded = declaredReferences.Any(reference =>
                     IsMatchByName(exception.From, reference.Source) &&
                     IsMatchByName(exception.To, reference.Target));

tests/ReferenceProtector.IntegrationTests/ReferenceProtector.IntegrationTests.cs

@@ -261,6 +261,55 @@ public async Task TechDebtException_StillNeeded_NoWarning_Async()
         Assert.Empty(warnings);
     }
 
+    /// <summary>
+    /// Validates that a tech debt exception scoped to a different project does NOT produce RP0006 during the current project's compilation.
+    /// </summary>
+    [Fact]
+    public async Task TechDebtException_ForDifferentProject_NoWarning_Async()
+    {
+        var projectA = CreateProject("A");
+        var projectB = CreateProject("B");
+        await AddProjectReference("A", "B");
+        var testRulesPath = Path.Combine(TestDirectory, "testRules.json");
+        // Use a From that references a project NOT in this solution (NonExistent.csproj),
+        // simulating a broad rule with tech debt exceptions for projects compiled separately.
+        File.WriteAllText(testRulesPath, $$"""
+        {
+            "ProjectDependencies": [
+            {
+                "From": "*",
+                "To": "*",
+                "LinkType": "Direct",
+                "Policy": "Forbidden",
+                "Description": "test rule",
+                "Exceptions": [
+                    {
+                        "From": "{{projectA.Replace("\\", "\\\\")}}",
+                        "To": "{{projectB.Replace("\\", "\\\\")}}",
+                        "Justification": "Tech debt for A",
+                        "IsTechDebt": true
+                    },
+                    {
+                        "From": "*NonExistent.csproj",
+                        "To": "*SomeLib.csproj",
+                        "Justification": "Tech debt for a project not in this compilation",
+                        "IsTechDebt": true
+                    }
+                ]
+            }           
+            ]
+        }
+    """);
+
+        var warnings = await Build(additionalArgs:
+            $"/p:DependencyRulesFile={testRulesPath}");
+
+        // A→B is covered by the first exception (still needed), so no RP0004 or RP0006 for A.
+        // The second exception (NonExistent→SomeLib) doesn't match any project being compiled,
+        // so it should NOT trigger RP0006 from either A or B.
+        Assert.Empty(warnings);
+    }
+
     /// <summary>
     /// Validates that a non-tech-debt exception that no longer matches does NOT produce an RP0006 warning.
     /// </summary>

tests/ReferenceProtector.IntegrationTests/ReferenceProtector.IntegrationTests.csproj

@@ -7,6 +7,16 @@
     </ProjectReference>    
   </ItemGroup>
 
+  <!-- Remove stale .nupkg files from artifacts before the Package project produces a new one.
+       Without this, NuGet may resolve to an older package version with a higher version number,
+       causing tests to run against stale analyzer code. -->
+  <Target Name="CleanStalePackages" BeforeTargets="ResolveProjectReferences">
+    <ItemGroup>
+      <_StalePackages Include="$(RepoRoot)\artifacts\*.nupkg" />
+    </ItemGroup>
+    <Delete Files="@(_StalePackages)" />
+  </Target>
+
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>