Ref https://twitter.com/swyx/status/1091959223406084096
terser-webpack-plugin used terser as default export.
import terser from 'terser';
// transpiled
var _terser = _interopRequireDefault(require("terser"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
Terser used exports only as a namespace. So it's normal to consume named imports in esm.
(function(exports) {
function minify() {}
exports["minify"] = minify;
})("undefined" != typeof module ? module.exports : Terser = {});
Then terser migrated to rollup which added esModule property to exports namespace.
(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('source-map')) :
typeof define === 'function' && define.amd ? define(['exports', 'source-map'], factory) :
(global = global || self, factory(global.Terser = {}, global.sourceMap));
}(this, function (exports, MOZ_SourceMap) { 'use strict';
function minify () {}
exports.minify = minify;
Object.defineProperty(exports, '__esModule', { value: true });
}));
Now babel interop trusts that imported object is a namespace with named and default exports as properties. However default property was missing. This broke the web. This is where default exports overusing let us down.
Why I've stopped exporting defaults from my JavaScript modules by Nicholas C. Zakas