test: add tests related to env

PR-URL: #1254
Reviewed-By: Michael Dawson <midawson@redhat.com

Author: JckXia

test/typed_threadsafe_function/typed_threadsafe_function_ptr.cc

@@ -16,12 +16,16 @@ static Value Test(const CallbackInfo& info) {
   return info.Env().Undefined();
 }
 
+static Value ExtractEnvNullValue(const CallbackInfo& info) {
+  return info.Env().Null();
+}
+
 }  // namespace
 
 Object InitTypedThreadSafeFunctionPtr(Env env) {
   Object exports = Object::New(env);
   exports["test"] = Function::New(env, Test);
-
+  exports["null"] = Function::New(env, ExtractEnvNullValue);
   return exports;
 }
 

test/typed_threadsafe_function/typed_threadsafe_function_ptr.js

@@ -1,7 +1,8 @@
 'use strict';
-
+const assert = require('assert');
 module.exports = require('../common').runTest(test);
 
 function test (binding) {
-  binding.typed_threadsafe_function_ptr.test({}, () => {});
+  assert(binding.typed_threadsafe_function_ptr.test({}, () => {}) === undefined);
+  assert(binding.typed_threadsafe_function_ptr.null() === null);
 }