diff --git a/README.md b/README.md
index 9773166..1584bd2 100644
--- a/README.md
+++ b/README.md
@@ -238,15 +238,14 @@ not necessary because `NSButton` embeds `NSControl` which in turn embeds
 receivers. Go will automatically find the indirectly embedded `NSView` and
 call the right method.
 
-Go's type inference appears to be slightly broken (as of 1.12.1) because
-the following does not work. Look out for this if you like to chain your
+Note that, since `InitWithFrame()` is defined only for `NSView` and returns
+an `NSView` type,
+the following will not work. Look out for this if you like to chain your
 `Alloc` and `Init` methods and are getting type errors:
 
 ```go
-//DO NOT DO THIS
+//DO NOT DO THIS -- InitWithFrame returns NSView, not NSButton
 b := ns.NSButtonAlloc().InitWithFrame(ns.MakeRect(100,100,200,200))
-//For some reason Go thinks b has type ns.NSView, because InitWithFrame is defined for ns.NSView,
-//even though NSButtonAlloc() returns an ns.NSButton.
 ```
 
 Go has no trouble finding embedded methods for your `NSButton` and will
diff --git a/types/convert.go b/types/convert.go
index b98b8ca..9af08d6 100644
--- a/types/convert.go
+++ b/types/convert.go
@@ -192,9 +192,10 @@ func _goType(ct string) string {
 	if IsGoInterface(ct) {
 		return ct
 	}
+	/*
 	if ct == "Id" {
 		ct = "Id"
-	}
+	}*/
 	if len(ct) > 1 && ShouldWrap(ct[1:]) {
 		return ct[1:]
 	}
@@ -296,7 +297,7 @@ func (t *Type) IsFunctionPtr() bool {
 
 func (t *Type) IsFunction() bool {
 	if t == nil {
-		fmt.Println("nil sent to IsFunction()")
+		//fmt.Println("nil sent to IsFunction()")
 		return false
 	}
 	if td := t.Typedef(); td != nil {
@@ -316,6 +317,9 @@ func (t *Type) IsValist() bool {
 }
 
 func (t *Type) ReturnType() *Type {
+	if td := t.Typedef(); td != nil {
+		return td.ReturnType()
+	}
 	if rt := t.Node.ReturnType(); rt != nil {
 		return NewType(rt,t.Class)
 	}
@@ -323,6 +327,9 @@ func (t *Type) ReturnType() *Type {
 }
 
 func (t *Type) IsPointer() bool {
+	if t == nil {
+		return false
+	}
 	if td := t.Typedef(); td != nil {
 		return td.IsPointer()
 	}
@@ -340,7 +347,7 @@ func (t *Type) CToGo(cval string) string {
 // Call a C function from Go with a given return type and parameter types
 func GoToC(name string, pnames, snames []string, rtype *Type, ptypes []*Type, fun bool) string {
 	if rtype == nil {
-		fmt.Println("nil sent to GoToC")
+		//fmt.Println("nil sent to GoToC")
 		return ""
 	}
 	var ret strings.Builder
diff --git a/types/convert_test.go b/types/convert_test.go
new file mode 100644
index 0000000..304d9ae
--- /dev/null
+++ b/types/convert_test.go
@@ -0,0 +1,324 @@
+package types
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func isNil(x interface{}) bool {
+	return x == nil ||
+		(reflect.ValueOf(x).Kind() == reflect.Ptr &&
+		reflect.ValueOf(x).IsNil())
+}
+
+func TestType(t *testing.T) {
+	i := 1
+
+	var str string
+	var n *Node
+	var tp *Type
+
+	chk := func(actual, expected interface{}) {
+		t.Run(fmt.Sprintf("TestType%d",i),func(t *testing.T) {
+			if isNil(actual) && isNil(expected) { return }
+			if !reflect.DeepEqual(actual,expected) {
+				t.Errorf("Test failed for %s\n",str)
+				fmt.Println("Actual:\n",actual)
+				fmt.Println("Expected:\n",expected)
+			}
+		})
+	}
+
+	chk_newtype := func() {
+		tp = NewTypeFromString(str,"")
+		chk(tp,&Type{ Node: n, Class: "" })
+	}
+
+	//tests on nil Type pointers:
+	chk(tp.BaseType(),nil)
+	chk(tp.CType(),"")
+	chk(tp.IsFunction(),false)
+	chk(tp.IsPointer(),false)
+	chk(tp.IsFunctionPtr(),false)
+	chk(tp.IsValist(),false)
+
+	str = "int"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypeSpecifier", "int", []*Node{} } } }
+	chk_newtype()
+	tint := tp
+
+	str = "NSObject"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypedefName", "NSObject", []*Node{} } } }
+	chk_newtype()
+	nso := tp
+
+	str = "NSString"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypedefName", "NSString", []*Node{} } } }
+	chk_newtype()
+	nst := tp
+
+	str = "NSString*"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypedefName", "NSString", []*Node{} },
+		&Node{ "Pointer", "*", []*Node{} } } }
+	chk_newtype()
+	chk(tp.IsPointer(),true)
+	chk(tp.Typedef(),nil)
+	tpNSString := tp
+
+	str = "myTypedef"
+	AddTypedef("myTypedef",tp)
+	n = &Node { "TypeName", "", []*Node{
+		&Node{ "TypedefName", "myTypedef", []*Node{} }}}
+	chk_newtype()
+	chk(tp.Typedef(),tpNSString)
+
+	str = "const NSArray <ObjectType * _Nonnull> *"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypeQualifier", "const", []*Node{} },
+		&Node{ "TypedefName", "NSArray", []*Node{} },
+		&Node{ "GenericList", "", []*Node{
+			&Node{ "Generic", "", []*Node{
+				&Node{ "TypedefName", "ObjectType", []*Node{} },
+				&Node{ "Pointer", "*", []*Node{} },
+				&Node{ "NullableAnnotation", "_Nonnull", []*Node{} } } } } },
+		&Node{ "Pointer", "*", []*Node{} } } }
+	chk_newtype()
+	chk(tp.CType(),"NSArray*")
+	chk(tp.CTypeAttrib(),"const NSArray*")
+	chk(tp.CGoType(),"*C.NSArray")
+	chk(tp.GoType(),"*NSArray")
+
+	SetTypeParam("MyClass","ObjectType","MyClass")
+	str = "id<ObjectType *>"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypedefName", "id", []*Node{} },
+		&Node{ "GenericList", "", []*Node{
+			&Node{ "Generic", "", []*Node{
+				&Node{ "TypedefName", "ObjectType", []*Node{} },
+				&Node{ "Pointer", "*", []*Node{} } } } } } } }
+	chk_newtype()
+	tp = NewType(n,"MyClass")
+	chk(tp.CType(),"NSObject*")
+	chk(tp.String(),
+`<TypeName> ''
+-<TypedefName> 'id'
+-<GenericList> ''
+--<Generic> ''
+---<TypedefName> 'MyClass'
+---<Pointer> '*'
+`)
+	x,_ := clean(nil,"MyClass")
+	chk(x,nil)
+	SetSuper("NSString","NSObject")
+	chk(Super("NSString"),"NSObject")
+
+	tp2 := tp.CloneToClass("NSObject")
+	chk(tp2.Class,"NSObject")
+
+	str = "you can't parse this"
+	tp = NewTypeFromString(str,"")
+	tp2 = &Type{}
+	chk(tp,tp2)
+
+	str = "id<ObjectType *>"
+	tp2 = NewTypeFromString(str,"MyClass")
+	chk(tp.BaseType(),tp)
+
+	str = "id<ObjectType *>*"
+	tp = NewTypeFromString(str,"MyClass")
+	chk(tp.BaseType(),tp2)
+	chk(tp.PointsTo(),tp2)
+	AddTypedef("myTypedef",tp)
+
+	str = "myTypedef"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypedefName", "myTypedef", []*Node{} } } }
+	chk_newtype()
+	chk(tp.PointsTo(),tp2)
+	chk(tp2.PointsTo(),nil)
+
+	chk(tp.GoTypeDecl(),`
+type MyTypedef **C.NSObject
+`)
+	chk(tp2.GoTypeDecl(),"")
+	chk(nst.GoTypeDecl(),`
+type NSString C.NSString
+`)
+	str = "void"
+	n = &Node{ "TypeName", "", []*Node{
+		&Node{ "TypeSpecifier", "void", []*Node{} } } }
+	chk_newtype()
+	chk(tp.GoTypeDecl(),"")
+	void := tp
+
+	str = "BOOL"
+	n,_ = Parse(str)
+	chk_newtype()
+	bl := tp
+
+	str = "void**"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.GoType(),"*unsafe.Pointer")
+	chk(tp.CToGo("var"),"(*unsafe.Pointer)(unsafe.Pointer(var))")
+	voidpp := tp
+
+	Wrap("NSObject")
+	str = "NSObject*"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.GoType(),"NSObject")
+
+	Wrap("NSString")
+	chk(nso.GoTypeDecl(),`
+type NSObject interface {
+	Ptr() unsafe.Pointer
+}
+`)
+	chk(nso.GoType(),"NSObject")
+
+	chk(nst.GoTypeDecl(),`
+type NSString struct { Id }
+func (o NSString) Ptr() unsafe.Pointer { return o.ptr }
+func (o Id) NSString() NSString {
+	ret := NSString{}
+	ret.ptr = o.ptr
+	return ret
+}
+`)
+	str = "int(void)"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.IsFunction(),true)
+	chk(tp.IsFunctionPtr(),false)
+	chk(tp.ReturnType().CType(),"int")
+
+	str = "int *(void)"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.IsFunction(),true)
+	chk(tp.ReturnType().CType(),"int*")
+	chk(tp.ReturnType().GoType(),"*Int")
+	fn := tp
+
+	AddTypedef("myTypedef",fn)
+	str = "myTypedef"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.IsFunction(),true)
+	chk(tp.IsFunctionPtr(),false)
+	chk(tp.ReturnType().CType(),"int*")
+
+	str = "int (*)(void)"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.IsFunction(),false)
+	chk(tp.IsPointer(),true)
+	chk(tp.IsFunctionPtr(),true)
+	chk(tp.ReturnType(),nil)
+	fnptr := tp
+
+	AddTypedef("myTypedef",fnptr)
+	str = "myTypedef"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.IsFunction(),false)
+	chk(tp.IsPointer(),true)
+	chk(tp.IsFunctionPtr(),true)
+	chk(tp.ReturnType(),nil)
+
+	chk(tp.IsValist(),false)
+	str = "__va_list_tag"
+	n,_ = Parse(str)
+	chk_newtype()
+	chk(tp.IsValist(),true)
+
+	str = "GoToC"
+	var rtype *Type
+	ptypes := []*Type{ nst, nso, tint, voidpp }
+	pnames := []string{"p1","p2","p3", "p4"}
+	snames := []string{"","","",""}
+
+	chk_gotoc := func(expected string) {
+		chk(GoToC("myFun",pnames,snames,rtype,ptypes,false),expected)
+	}
+
+	chk_gotoc("")
+
+	rtype = void
+	chk_gotoc(`C.myFun(p1.Ptr(), p2.Ptr(), (C.int)(p3), unsafe.Pointer(p4))`)
+
+	rtype = bl
+	chk_gotoc(
+`ret := (C.myFun(p1.Ptr(), p2.Ptr(), (C.int)(p3), unsafe.Pointer(p4))) != 0
+	return ret`)
+
+	rtype = voidpp
+	chk_gotoc(
+`ret := (*unsafe.Pointer)(unsafe.Pointer(C.myFun(p1.Ptr(), p2.Ptr(), (C.int)(p3), unsafe.Pointer(p4))))
+	return ret`)
+
+	rtype = nst
+	chk_gotoc(
+`ret := NSString{}
+	ret.ptr = C.myFun(p1.Ptr(), p2.Ptr(), (C.int)(p3), unsafe.Pointer(p4))
+	return ret`)
+
+	rtype = nso
+	chk_gotoc(
+`ret := Id{}
+	ret.ptr = C.myFun(p1.Ptr(), p2.Ptr(), (C.int)(p3), unsafe.Pointer(p4))
+	return ret`)
+
+	ptypes[1].Variadic = true
+	chk_gotoc(
+`ret := Id{}
+	ret.ptr = C.myFun(p1.Ptr(), unsafe.Pointer(&p2), (C.int)(p3), unsafe.Pointer(p4))
+	return ret`)
+	ptypes[1].Variadic = false
+
+	snames[1] = "p2p"
+	chk_gotoc(
+`ret := Id{}
+	ret.ptr = C.myFun(p1.Ptr(), p2.Ptr(), (C.int)(p3), unsafe.Pointer(p4))
+	(*p2) = (*p2)[:cap(*p2)]
+	for i := 0; i < len(*p2); i++ {
+		if p2p[i] == nil {
+			(*p2) = (*p2)[:i]
+			break
+		}
+		(*p2)[i].ptr = p2p[i]
+	}
+	return ret`)
+	snames[1] = ""
+	snames[2] = "p3p"
+	chk_gotoc(
+`ret := Id{}
+	ret.ptr = C.myFun(p1.Ptr(), p2.Ptr(), unsafe.Pointer(&p3p[0]), unsafe.Pointer(p4))
+	(*p3) = (*p3)[:cap(*p3)]
+	for i := 0; i < len(*p3); i++ {
+		if p3p[i] == nil {
+			(*p3) = (*p3)[:i]
+			break
+		}
+		(*p3)[i].ptr = p3p[i]
+	}
+	return ret`)
+	chk(GoToC("myFun",pnames,snames,rtype,ptypes,true),
+`ret := Id{}
+	ret.ptr = C.myFun(p1.Ptr(), p2.Ptr(), unsafe.Pointer(&p3p[0]), (**C.void)(p4))
+	(*p3) = (*p3)[:cap(*p3)]
+	for i := 0; i < len(*p3); i++ {
+		if p3p[i] == nil {
+			(*p3) = (*p3)[:i]
+			break
+		}
+		(*p3)[i].ptr = p3p[i]
+	}
+	return ret`)
+}