Fix DeclarationFinder.FindInterface

Previously, this completely ignored the selection passed to it. Now, it only returns interfaces such that the selection is inside an Implements statement for it or contains the Implements statement. If multiple Implements statements are contained, it takes the first it comes across.

Author: MDoerner

Rubberduck.Parsing/VBA/DeclarationCaching/DeclarationFinder.cs

@@ -420,8 +420,12 @@ public ClassModuleDeclaration FindInterface(QualifiedSelection selection)
         {
             return FindAllUserInterfaces()
                 .FirstOrDefault(declaration => declaration.References
-                    .Any(reference => reference.Context.GetAncestor<VBAParser.ImplementsStmtContext>() != null 
-                                      && ReferenceEquals(reference.Declaration, declaration)));
+                    .Where(reference => reference.QualifiedModuleName.Equals(selection.QualifiedName))
+                    .Select(reference => reference.Context.GetAncestor<VBAParser.ImplementsStmtContext>())
+                    .Where(context => context != null)
+                    .Select(context => context.GetSelection())
+                    .Any(contextSelection => contextSelection.Contains(selection.Selection) 
+                                             || selection.Selection.Contains(contextSelection)));
         }
 
         /// <summary>

RubberduckTests/Refactoring/ImplementInterfaceTests.cs

@@ -60,6 +60,49 @@ End Sub
             }
         }
 
+        [Test]
+        [Category("Refactorings")]
+        [Category("Implement Interface")]
+        public void DoesNotImplementInterface_SelectionNotOnImplementsStatement()
+        {
+            //Input
+            const string inputCode1 =
+                @"Public Sub Foo()
+End Sub";
+
+            const string inputCode2 =
+                @"Implements Class1
+   
+";
+
+            //Expectation
+            const string expectedCode =
+                @"Implements Class1
+   
+";
+
+            var builder = new MockVbeBuilder();
+            var project = builder.ProjectBuilder("TestProject1", ProjectProtection.Unprotected)
+                .AddComponent("Class1", ComponentType.ClassModule, inputCode1)
+                .AddComponent("Class2", ComponentType.ClassModule, inputCode2)
+                .Build();
+            var vbe = builder.AddProject(project).Build();
+            var component = project.Object.VBComponents[1];
+
+            var (state, rewritingManager) = MockParser.CreateAndParseWithRewritingManager(vbe.Object);
+            using (state)
+            {
+
+                var qualifiedSelection = new QualifiedSelection(new QualifiedModuleName(component), new Selection(2,2));
+
+                var refactoring = TestRefactoring(vbe.Object, rewritingManager, state);
+                refactoring.Refactor(qualifiedSelection);
+
+                var actualCode = component.CodeModule.Content();
+                Assert.AreEqual(expectedCode, actualCode);
+            }
+        }
+
         [Test]
         [Category("Refactorings")]
         [Category("Implement Interface")]
@@ -1018,6 +1061,57 @@ End Property
             }
         }
 
+        [Test]
+        [Category("Refactorings")]
+        [Category("Implement Interface")]
+        public void ImplementsCorrectInterface_MultipleInterfaces()
+        {
+            //Input
+            const string inputCode1 =
+                @"Public Sub Foo()
+End Sub";
+
+            const string inputCode2 =
+                @"Implements Class1
+Implements Class3";
+
+            const string inputCode3 =
+                @"Public Sub Foo()
+End Sub";
+
+            //Expectation
+            const string expectedCode =
+                @"Implements Class1
+Implements Class3
+
+Private Sub Class1_Foo()
+    Err.Raise 5 'TODO implement interface member
+End Sub
+";
+
+            var builder = new MockVbeBuilder();
+            var project = builder.ProjectBuilder("TestProject1", ProjectProtection.Unprotected)
+                .AddComponent("Class1", ComponentType.ClassModule, inputCode1)
+                .AddComponent("Class2", ComponentType.ClassModule, inputCode2)
+                .AddComponent("Class3", ComponentType.ClassModule, inputCode3)
+                .Build();
+            var vbe = builder.AddProject(project).Build();
+            var component = project.Object.VBComponents[1];
+
+            var (state, rewritingManager) = MockParser.CreateAndParseWithRewritingManager(vbe.Object);
+            using (state)
+            {
+
+                var qualifiedSelection = new QualifiedSelection(new QualifiedModuleName(component), new Selection(1,1));
+
+                var refactoring = TestRefactoring(vbe.Object, rewritingManager, state);
+                refactoring.Refactor(qualifiedSelection);
+
+                var actualCode = component.CodeModule.Content();
+                Assert.AreEqual(expectedCode, actualCode);
+            }
+        }
+
         private static IRefactoring TestRefactoring(IVBE vbe, IRewritingManager rewritingManager, RubberduckParserState state, IMessageBox msgBox = null)
         {
             var selectionService = MockedSelectionService(vbe.GetActiveSelection());