Return doc comment template for interfaces and method signatures

src/services/jsDoc.ts

@@ -266,10 +266,12 @@ namespace ts.JsDoc {
                 case SyntaxKind.FunctionDeclaration:
                 case SyntaxKind.MethodDeclaration:
                 case SyntaxKind.Constructor:
-                    const { parameters } = commentOwner as FunctionDeclaration | MethodDeclaration | ConstructorDeclaration;
+                case SyntaxKind.MethodSignature:
+                    const { parameters } = commentOwner as FunctionDeclaration | MethodDeclaration | ConstructorDeclaration | MethodSignature;
                     return { commentOwner, parameters };
 
                 case SyntaxKind.ClassDeclaration:
+                case SyntaxKind.InterfaceDeclaration:
                     return { commentOwner };
 
                 case SyntaxKind.VariableStatement: {

tests/cases/fourslash/docCommentTemplateInterfaces.ts

@@ -0,0 +1,23 @@
+/// <reference path='fourslash.ts' />
+
+/////*interfaceFoo*/
+////interface Foo {
+////    /*propertybar*/
+////    bar: any;
+////
+////    /*methodbaz*/
+////    baz(message: any): void;
+////}
+
+verify.docCommentTemplateAt("interfaceFoo", /*expectedOffset*/ 8,
+`/**
+ * 
+ */`);
+
+verify.emptyDocCommentTemplateAt("propertybar");
+
+verify.docCommentTemplateAt("methodbaz", /*expectedOffset*/ 12,
+   `/**
+     * 
+     * @param message
+     */`);