Given this module module-name:

// module-name.js
export default function foo(){ console.log("foo");}
export function bar(){ console.log("bar");}
console.log("hello world");

Consider the following cases which have been tested in node.js v9.11.1 using the command node --experimental-modules some-importer.mjs:

Importing the default export

// import defaultExport from "module-name";
import fizzbuzz from "module-name";

Only the default export will be available thus:

• fizzbuzz (which is foo) is available
• bar is not available
• console.log(hello world) will have been run

Importing all exports using * wildcard

import * as name from "module-name";

All exports are available but attached to an Object identified as name:

• foo is not available
• bar is not available
• name.foo is not available (though you think it would be)
• name.bar is available
• console.log(hello world) will have been run

Importing an identified export

// import { export } from "module-name";
import { bar } from "module-name"

Only the identified export is available:

• foo is not available
• bar is available
• console.log(hello world) will have been run

Importing an identified export as an alias

// import { export as alias } from "module-name";
import { bar as mybar } from "module-name";

Only the identified export is available and only as the identified alias:

• foo is not available
• bar is not available
• mybar (which is bar) is available
• console.log(hello world) will have been run

Importing the default export and using the * wildcard

// import defaultExport, * as name from "module-name";
import fizzbuzz, * as name from "module-name";

The default item from the module can be referenced as defaultExport and all other exported items are attached to name

• fizzbuzz (which is foo) is available
• bar is not available
• name.bar is available
• console.log(hello world) will have been run

No actual identified imports

import "module-name";

The module is loaded, but nothing is actually available in the module that imported. This means that file runs but nothing is exposed

• foo is not available
• bar is not available
• console.log(hello world) will have been run