shouldLoadAsEsm.js
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'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
exports.clearCachedLookups = clearCachedLookups;
exports.default = cachedShouldLoadAsEsm;
function _path() {
const data = require('path');
_path = function () {
return data;
};
return data;
}
function _vm() {
const data = require('vm');
_vm = function () {
return data;
};
return data;
}
function _readPkgUp() {
const data = _interopRequireDefault(require('read-pkg-up'));
_readPkgUp = function () {
return data;
};
return data;
}
function _interopRequireDefault(obj) {
return obj && obj.__esModule ? obj : {default: obj};
}
/**
* Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
// @ts-expect-error: experimental, not added to the types
const runtimeSupportsVmModules = typeof _vm().SyntheticModule === 'function';
const cachedFileLookups = new Map();
const cachedDirLookups = new Map();
function clearCachedLookups() {
cachedFileLookups.clear();
cachedDirLookups.clear();
}
function cachedShouldLoadAsEsm(path) {
let cachedLookup = cachedFileLookups.get(path);
if (cachedLookup === undefined) {
cachedLookup = shouldLoadAsEsm(path);
cachedFileLookups.set(path, cachedLookup);
}
return cachedLookup;
} // this is a bad version of what https://github.com/nodejs/modules/issues/393 would provide
function shouldLoadAsEsm(path) {
if (!runtimeSupportsVmModules) {
return false;
}
const extension = (0, _path().extname)(path);
if (extension === '.mjs') {
return true;
}
if (extension === '.cjs') {
return false;
} // this isn't correct - we might wanna load any file as a module (using synthetic module)
// do we need an option to Jest so people can opt in to ESM for non-js?
if (extension !== '.js') {
return false;
}
const cwd = (0, _path().dirname)(path);
let cachedLookup = cachedDirLookups.get(cwd);
if (cachedLookup === undefined) {
cachedLookup = cachedPkgCheck(cwd);
cachedFileLookups.set(cwd, cachedLookup);
}
return cachedLookup;
}
function cachedPkgCheck(cwd) {
// TODO: can we cache lookups somehow?
const pkg = _readPkgUp().default.sync({
cwd,
normalize: false
});
if (!pkg) {
return false;
}
return pkg.packageJson.type === 'module';
}