Fixed incorrect handling generic type alias

Fixes #4

Author: timocov

src/transformer.ts

@@ -264,13 +264,6 @@ function createTransformerFactory(program: ts.Program, options?: Partial<RenameO
 				}
 			}
 
-			if (type.aliasTypeArguments !== undefined) {
-				const hasExternalSubType = type.aliasTypeArguments.some((t: ts.Type) => isTypePropertyExternal(t, typePropertyName));
-				if (hasExternalSubType) {
-					return hasExternalSubType;
-				}
-			}
-
 			const symbol = type.getSymbol();
 			if (symbol !== undefined) {
 				const declarations = getDeclarationsForSymbol(symbol);

tests/test-cases/generic-with-string-type/input.ts

@@ -0,0 +1,15 @@
+class Foo<Type extends string> {
+	public search(): void {}
+}
+
+type StringFoo<T extends string> = Foo<T>;
+
+class Bar {
+	private foo: StringFoo<string> = new Foo();
+
+	public doSomething(): void {
+		this.foo.search();
+	}
+}
+
+export interface FooBar {}

tests/test-cases/generic-with-string-type/output.js

@@ -0,0 +1,17 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    Foo.prototype._internal_search = function () { };
+    return Foo;
+}());
+var Bar = /** @class */ (function () {
+    function Bar() {
+        this._private_foo = new Foo();
+    }
+    Bar.prototype._internal_doSomething = function () {
+        this._private_foo._internal_search();
+    };
+    return Bar;
+}());