test: dd check for nullptr inside String init

PR-URL: nodejs#1015
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Kevin Eady <kevin.c.eady@gmail.com>

napi-inl.h

@@ -900,6 +900,11 @@ inline String String::New(napi_env env, const std::u16string& val) {
 }
 
 inline String String::New(napi_env env, const char* val) {
+  if (val == nullptr) {
+    NAPI_THROW(
+        TypeError::New(env, "String::New received a nullpointer as a value"),
+        Napi::String());
+  }
   napi_value value;
   napi_status status = napi_create_string_utf8(env, val, std::strlen(val), &value);
   NAPI_THROW_IF_FAILED(env, status, String());

test/name.cc

@@ -82,11 +82,18 @@ Value CheckSymbol(const CallbackInfo& info) {
   return Boolean::New(info.Env(), info[0].Type() == napi_symbol);
 }
 
+void AssertErrorThrownWhenPassedNullptr(const CallbackInfo& info) {
+  const char* nullStr = nullptr;
+  String::New(info.Env(), nullStr);
+}
+
 Object InitName(Env env) {
   Object exports = Object::New(env);
 
   exports["echoString"] = Function::New(env, EchoString);
   exports["createString"] = Function::New(env, CreateString);
+  exports["nullStringShouldThrow"] =
+      Function::New(env, AssertErrorThrownWhenPassedNullptr);
   exports["checkString"] = Function::New(env, CheckString);
   exports["createSymbol"] = Function::New(env, CreateSymbol);
   exports["checkSymbol"] = Function::New(env, CheckSymbol);

test/name.js

@@ -7,6 +7,11 @@ module.exports = require('./common').runTest(test);
 function test(binding) {
   const expected = '123456789';
 
+
+  assert.throws(binding.name.nullStringShouldThrow, {
+    name: 'TypeError',
+    message: 'String::New received a nullpointer as a value',
+  });
   assert.ok(binding.name.checkString(expected, 'utf8'));
   assert.ok(binding.name.checkString(expected, 'utf16'));
   assert.ok(binding.name.checkString(expected.substr(0, 3), 'utf8', 3));