Merge pull request #24 from sharwell/implicit-struct-ctor

Structs always have an implicit constructor

Author: sharwell

PublicApiAnalyzer/PublicApiAnalyzer.Test/ApiDesign/DeclarePublicAPIAnalyzerTests.cs

@@ -189,6 +189,50 @@ public class C
             await this.VerifyCSharpDiagnosticAsync(source, expected, CancellationToken.None).ConfigureAwait(false);
         }
 
+        [Fact]
+        public async Task ShippedTextWithMissingImplicitStructConstructorAsync()
+        {
+            var source = @"
+public struct C
+{
+}
+";
+
+            this.shippedText = @"
+C";
+            this.unshippedText = string.Empty;
+
+            // Test0.cs(2,15): warning RS0016: Symbol 'implicit constructor for C' is not part of the declared API.
+            string arg = string.Format(RoslynDiagnosticsResources.PublicImplicitConstructorErrorMessageName, "C");
+            var expected = this.CSharpDiagnostic(DeclarePublicAPIAnalyzer.DeclareNewApiRule).WithArguments(arg).WithLocation(2, 15);
+
+            await this.VerifyCSharpDiagnosticAsync(source, expected, CancellationToken.None).ConfigureAwait(false);
+        }
+
+        [Fact]
+        public async Task ShippedTextWithMissingImplicitStructConstructorWithOtherOverloadsAsync()
+        {
+            var source = @"
+public struct C
+{
+    public C(int value)
+    {
+    }
+}
+";
+
+            this.shippedText = @"
+C
+C.C(int value) -> void";
+            this.unshippedText = string.Empty;
+
+            // Test0.cs(2,15): warning RS0016: Symbol 'implicit constructor for C' is not part of the declared API.
+            string arg = string.Format(RoslynDiagnosticsResources.PublicImplicitConstructorErrorMessageName, "C");
+            var expected = this.CSharpDiagnostic(DeclarePublicAPIAnalyzer.DeclareNewApiRule).WithArguments(arg).WithLocation(2, 15);
+
+            await this.VerifyCSharpDiagnosticAsync(source, expected, CancellationToken.None).ConfigureAwait(false);
+        }
+
         [Fact]
         public async Task ShippedTextWithImplicitConstructorAndBreakingCodeChangeAsync()
         {

PublicApiAnalyzer/PublicApiAnalyzer/ApiDesign/DeclarePublicAPIAnalyzer.Impl.cs

@@ -188,13 +188,13 @@ private void OnSymbolActionCore(ISymbol symbol, Action<Diagnostic> reportDiagnos
                 if (symbol.Kind == SymbolKind.NamedType)
                 {
                     var namedType = (INamedTypeSymbol)symbol;
-                    if (namedType.InstanceConstructors.Length == 1 &&
-                        (namedType.TypeKind == TypeKind.Class || namedType.TypeKind == TypeKind.Struct))
+                    if ((namedType.InstanceConstructors.Length == 1 && namedType.TypeKind == TypeKind.Class)
+                        || namedType.TypeKind == TypeKind.Struct)
                     {
-                        var instanceConstructor = namedType.InstanceConstructors[0];
-                        if (instanceConstructor.IsImplicitlyDeclared)
+                        var implicitConstructor = namedType.InstanceConstructors.SingleOrDefault(x => x.IsImplicitlyDeclared);
+                        if (implicitConstructor != null)
                         {
-                            this.OnSymbolActionCore(instanceConstructor, reportDiagnostic, isImplicitlyDeclaredConstructor: true, explicitLocation: explicitLocation);
+                            this.OnSymbolActionCore(implicitConstructor, reportDiagnostic, isImplicitlyDeclaredConstructor: true, explicitLocation: explicitLocation);
                         }
                     }
                 }