Rename CastType to AliasedType

This field stores a Ref if a type is a builtin that has been aliased. In
most cases if this is set, we want to use this as the type signature
instead of the named type resolved from the schema.

codegen/type.go

@@ -26,8 +26,8 @@ type Ref struct {
 type Type struct {
 	*NamedType
 
-	Modifiers []string
-	CastType  *Ref // the type to cast to when unmarshalling
+	Modifiers   []string
+	AliasedType *Ref
 }
 
 const (
@@ -47,6 +47,9 @@ func (t Ref) PkgDot() string {
 }
 
 func (t Type) Signature() string {
+	if t.AliasedType != nil {
+		return strings.Join(t.Modifiers, "") + t.AliasedType.FullName()
+	}
 	return strings.Join(t.Modifiers, "") + t.FullName()
 }
 
@@ -125,11 +128,11 @@ func (t Type) unmarshal(result, raw string, remainingMods []string, depth int) s
 	}
 
 	realResult := result
-	if t.CastType != nil {
+	if t.AliasedType != nil {
 		result = "castTmp"
 	}
 
-	return tpl(`{{- if .t.CastType }}
+	return tpl(`{{- if .t.AliasedType }}
 			var castTmp {{.t.FullName}}
 		{{ end }}
 			{{- if eq .t.GoType "map[string]interface{}" }}
@@ -139,8 +142,8 @@ func (t Type) unmarshal(result, raw string, remainingMods []string, depth int) s
 			{{- else -}}
 				err = (&{{.result}}).UnmarshalGQL({{.raw}})
 			{{- end }}
-		{{- if .t.CastType }}
-			{{ .realResult }} = {{.t.CastType.FullName}}(castTmp)
+		{{- if .t.AliasedType }}
+			{{ .realResult }} = {{.t.AliasedType.FullName}}(castTmp)
 		{{- end }}`, map[string]interface{}{
 		"realResult": realResult,
 		"result":     result,
@@ -150,7 +153,7 @@ func (t Type) unmarshal(result, raw string, remainingMods []string, depth int) s
 }
 
 func (t Type) Marshal(val string) string {
-	if t.CastType != nil {
+	if t.AliasedType != nil {
 		val = t.GoType + "(" + val + ")"
 	}
 

codegen/util.go

@@ -276,7 +276,7 @@ func validateTypeBinding(imports *Imports, field *Field, goType types.Type) erro
 		field.Type.Modifiers = modifiersFromGoType(goType)
 		pkg, typ := pkgAndType(goType.String())
 		imp := imports.findByPath(pkg)
-		field.CastType = &Ref{GoType: typ, Import: imp}
+		field.AliasedType = &Ref{GoType: typ, Import: imp}
 		return nil
 	}