Possible regression in 0.8.7 due to multiple instances of graphql?

[mattkrick]

Hi there! When trying to upgrade, I kept getting the following error:

Error: unsupported type: String!

While debugging, I saw that isNonNullType was returning false when it shouldn't for String! in the following compiled code.

if ((0, import_graphql.isNonNullType)(type)) {
    type = type.ofType;
    const nullErrorStr = `"Cannot return null for non-nullable field ${parentType.name}.${getFieldNodesName(fieldNodes)}."`;
    body += `(${GLOBAL_NULL_ERRORS_NAME}.push(${createErrorObject(
      context,
      fieldNodes,
      previousPath,
      nullErrorStr
    )}), null) :`;
    errorDestination = GLOBAL_NULL_ERRORS_NAME;
  } 

Digging deeper, I saw it was because import_graphql was coming from the following webpackified package:

/***/ 500722:
/***/ ((__unused_webpack___webpack_module__, __webpack_exports__, __webpack_require__) => {

"use strict";
// ESM COMPAT FLAG
__webpack_require__.r(__webpack_exports__);

whereas e.g. definitions were coming from a different ESM package, which i didn't install, but I believe is used internally by this package

/***/ 763754:
/***/ ((__unused_webpack_module, exports, __webpack_require__) => {

"use strict";


Object.defineProperty(exports, "__esModule", ({
  value: true,
}));

Since isNonNullType uses instanceof internally, I assume the use of different graphql packages is the culprit. I only have 1 graphql installed in my project, so I was wondering if it's because of #252 or #257?