test-module

index.browser.esm.js

console.log('Loaded test-module via pkg.browser');

export function logModule() {
  console.log('`logModule` called in test-module');
}

export function totallyUnused() {
  console.log('I go totally unused!');
}

index.browser.js

console.log('Loaded test-module via pkg.browser');

function logModule() {
  console.log('`logModule` called in test-module');
}

function totallyUnused() {
  console.log('I go totally unused!');
}

exports.logModule = logModule;
exports.totallyUnused = totallyUnused;

index.esm.js

console.log('Loaded test-module via pkg.module');

export function logModule() {
  console.log('`logModule` called in test-module');
}

export function totallyUnused() {
  console.log('I go totally unused!');
}

index.js

console.log('Loaded test-module via pkg.main');

function logModule() {
  console.log('`logModule` called in test-module');
}

function totallyUnused() {
  console.log('I go totally unused!');
}

exports.logModule = logModule;
exports.totallyUnused = totallyUnused;

package.json

{
  "name": "test-module",
  "version": "1.0.0",
  "description": "A test module exporting a `pkg.module`, `pkg.browser`, and `pkg.main`",
  "author": "Josh Crowther <jshcrowthe@gmail.com>",
  "license": "MIT",
  "main": "index.js",
  "browser": { 
    "index.js": "index.browser.js",
    "index.esm.js": "index.browser.esm.js",
  "module": "index.esm.js",
  "jsnext:main": "dist/index.esm.js"
}