Add some tests for constructor in IDL interface.

Rewrite examples/ tests using jest.

ISSUE=#99,#100

core/js_type_traits.h

@@ -50,4 +50,9 @@ inline Napi::Value JSTypeTraits(Napi::Env env, int64_t value) {
   return Napi::Number::New(env, value);
 }
 
+template <>
+inline Napi::Value JSTypeTraits(Napi::Env env, const std::string value) {
+  return Napi::String::New(env, value);
+}
+
 #endif  // CORE_JS_TYPE_TRAITS_H_

test/interface_constructor.test.ts

@@ -22,3 +22,37 @@ test('Default constructor', async () => {
   let test_interface: bacardi.TestInterface = new bacardi.TestInterface();
   expect(test_interface instanceof bacardi.TestInterface).toBe(true);
 });
+
+test('Calling undefined constructor should throw error', async () => {
+  expect(() => {
+    // There is no TestInterface(string) constructor.
+    new bacardi.TestInterface('Wrong argument');
+  }).toThrowError();
+
+  expect(() => {
+    // There is no TestInterface(number, number, number) constructor.
+    new bacardi.TestInterface(1, 2, 3);
+  }).toThrowError();
+});
+
+test('When creating two objects, should be differnt instances', async () => {
+  let instance1: bacardi.TestInterface = new bacardi.TestInterface();
+  let instance2: bacardi.TestInterface = new bacardi.TestInterface();
+  expect(instance1 !== instance2).toBe(true);
+});
+
+test('Test for constructor overloading', async () => {
+  let constructor1 = new bacardi.TestInterface();
+  expect(constructor1.getCalledConstructorInfo()).toBe('Constructor()');
+
+  let constructor2 = new bacardi.TestInterface(1);
+  expect(constructor2.getCalledConstructorInfo()).toBe('Constructor(long)');
+
+  let constructor3 = new bacardi.TestInterface(2, 3);
+  expect(constructor3.getCalledConstructorInfo())
+      .toBe('Constructor(long, long)');
+
+  let constructor4 = new bacardi.TestInterface('hello', 'world');
+  expect(constructor4.getCalledConstructorInfo())
+      .toBe('Constructor(string, string)');
+});

test/test_interface.cc

@@ -16,4 +16,17 @@
 
 #include "test/test_interface.h"
 
-TestInterface::TestInterface() {}
+TestInterface::TestInterface() : called_constructor_info_("Constructor()") {}
+
+TestInterface::TestInterface(long createTime)
+    : called_constructor_info_("Constructor(long)") {}
+
+TestInterface::TestInterface(long arg1, long arg2)
+    : called_constructor_info_("Constructor(long, long)") {}
+
+TestInterface::TestInterface(const std::string& msg1, const std::string& msg2)
+    : called_constructor_info_("Constructor(string, string)") {}
+
+const std::string& TestInterface::GetCalledConstructorInfo() const {
+  return called_constructor_info_;
+}

test/test_interface.h

@@ -17,9 +17,19 @@
 #ifndef TEST_TEST_INTERFACE_H_
 #define TEST_TEST_INTERFACE_H_
 
+#include <string>
+
 class TestInterface {
  public:
   TestInterface();
+  TestInterface(long number);
+  TestInterface(long number1, long number2);
+  TestInterface(const std::string& string1, const std::string& string2);
+
+  const std::string& GetCalledConstructorInfo() const;
+
+ private:
+  const std::string called_constructor_info_;
 };
 
 #endif  // TEST_TEST_INTERFACE_H_

test/test_interface.idl

@@ -14,5 +14,13 @@
  * limitations under the License.
  */
 
+[
+  Constructor(),
+  Constructor(long number),
+  Constructor(long number1, long number2),
+  Constructor(string string1, string string2)
+]
 interface TestInterface {
+  // FIXME(zino): It's better to use attribute instead of method.
+  string getCalledConstructorInfo();
 };