babel prevents ESM import

[noraj]

I'm trying to port the CommonJS (CJS) import to a ECMAScript Modules (ESM) import. cf. https://gist.github.com/noraj/007a943dc781dc8dd3198a29205bae04

From:

var jest = require('gulp-jest').default;

to

import gulpJest from 'gulp-jest';

But it fails with the following error when running gulp:

[18:00:50] TypeError: gulpJest is not a function
    at test_data (file:///home/noraj/Dev/rawsec-cybersecurity-inventory/gulpfile.mjs:178:15)
    at bound (node:domain:433:15)
    at runBound (node:domain:444:12)
    at asyncRunner (/home/noraj/Dev/rawsec-cybersecurity-inventory/node_modules/async-done/index.js:55:18)
    at process.processTicksAndRejections (node:internal/process/task_queues:77:11

However node_modules/gulp-jest/lib/index.js seems to have an uncommon way to export.

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;

...

var _default = function _default() {...};

exports["default"] = _default;

Could you provide me an example to how to import gulp-jest in a .mjs file or maybe patch the export if it's the cause.

[noraj]

I just tested and adding module.exports = _default; at the end of the script made it work, like it's done in https://github.com/colynb/gulp-data/blob/master/index.js or https://github.com/gulp-community/gulp-pug/blob/master/index.js.

ESM export example: https://github.com/sindresorhus/del/blob/main/index.js.

[noraj]

Seems to be fixed in https://github.com/Nerajno/gulp-jest/blob/master/src/index.js, it just lacks a new release. The reported repository on the last yarn / npmjs (4.0.4) release is https://github.com/aarontrank/gulp-jest and it's not using ESM at all.

• https://yarnpkg.com/package/gulp-jest
• https://www.npmjs.com/package/gulp-jest

but it seems other package are redirecting to your repository

• https://yarnpkg.com/package/@jacobq/gulp-jest
• https://github.com/alansouzati/gulp-jest

[noraj]

yarn add gulp-jest

node_modules/gulp-jest/lib/index.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;

var _pluginError = _interopRequireDefault(require("plugin-error"));

var _through = _interopRequireDefault(require("through2"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

var _require = require('@jest/core'),
    runCLI = _require.runCLI;

var _default = function _default() {
  var options = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
  return _through["default"].obj(function (file, enc, cb) {
    options = Object.assign({
      rootDir: file ? process.cwd() : undefined
    }, options);
    runCLI(options, [options.rootDir]).then(function (_ref) {
      var results = _ref.results;

      if (results.numFailedTests || results.numFailedTestSuites) {
        cb(new _pluginError["default"]('gulp-jest', {
          message: 'Tests Failed'
        }));
      } else if (typeof results.success !== 'undefined' && !results.success) {
        if (results.snapshot && results.snapshot.failure) {
          cb(new _pluginError["default"]('gulp-jest', {
            message: 'Tests Failed due to coverage snapshot failure'
          }));
        } else {
          cb(new _pluginError["default"]('gulp-jest', {
            message: 'Tests Failed due to coverage threshold breaches'
          }));
        }
      } else {
        cb();
      }
    });
  });
};

exports["default"] = _default;

[noraj]

gulp-js 4.0.4 package is up to date from this repository. It's babel that is generating this horrible code.

$ git clone https://github.com/Nerajno/gulp-jest
$ cd gulp-jest
$ yarn install
$ yarn run build
$ cat lib/index.js

[noraj]

In https://www.bigbinary.com/blog/helping-babel-move-to-esm, they give an example where

const rollupBabel = require("@rollup/plugin-babel").default;

is replaced with

import { babel as rollupBabel } from "@rollup/plugin-babel";

But replacing

var jest = require('gulp-jest').default;

with

import { jest as gulpJest } from 'gulp-jest';

But it always end in:

SyntaxError: Named export 'jest' not found. The requested module 'gulp-jest' is a CommonJS module, which may not support all module.exports as named exports.

I can't figure what is the export name.

This doesn't work either.

import * as gulpJest from 'gulp-jest';

[noraj]

This seems to be related to the usage of @babel/plugin-transform-modules-commonjs that is included in @babel/preset-env.

[noraj]

Some projects like babel/babel#11701 has made some work to publish both as ESM or CJS cf. https://github.com/babel/babel/pull/13414/files

[SamesJeabrook]

Has there been any update on this as I'm also stuck at this point and may have to look at using different tools.

[noraj]

No, the project seems abandoned. The author seems to only merge dependabot PR from times to times but as no been committing since April and has never given any answer for this issue for one year. The last npmjs release is 3 years old. I think I'll drop this dependency and replace the script:

  "scripts": {
-    "test": "gulp test"
+    "test": "jest"
  },