Difference between ES2015 `import * as` vs just plain `import` - import

Question

I just fixed a bug by changing import * as CodeMirror to just plain import CodeMirror.
I copied this code. (Porting it from TypeScript)
import * as CodeMirror worked until an addon was imported for its side effects: the expected new fold property was undefined.
Questions: (I am trying to understand what happened better)
What is going on? How did this change fix the bug?
Who is adding the default property to CodeMirror? (Or more likely: wrapping the module inside another object that looks very similar) The most likely suspects:
JavaScript modules (ES2015)
Babel
Webpack
CoffeeScript
CodeMirror
Is there a better way to accomplish what I was trying to achieve?
More details:
This code doesn't work as expected:
import * as CodeMirror from 'codemirror'
import 'codemirror/addon/fold/indent-fold.js' # should add `fold` object to `CodeMirror`
console.log typeof CodeMirror ## 'object'
console.log typeof CodeMirror.fold ## 'undefined'
console.log typeof CodeMirror.default ## 'function'
## Work-around:
console.log typeof CodeMirror.default.fold ## 'object'
This code works as expected:
import CodeMirror from 'codemirror'
import 'codemirror/addon/fold/indent-fold.js' # should add `fold` object to `CodeMirror`
console.log typeof CodeMirror ## 'function'
console.log typeof CodeMirror.fold ## 'object'
console.log typeof CodeMirror.default ## 'undefined'
I have already studied these resources, but they have not helped me fully understand what happened:
JS import reference
JS export reference
CoffeeScript modules

Answer 1

Let's assume you have a very simple module named 'test-module', in it you have:
var test = 'test';
export default test;
export function helloWorld () { ... };
When you do:
import something from 'test-module';
you are only importing the default export of 'some-module'. In this case, it is the string test. The default export can be anything, object, function, etc.
When you do:
import {helloWorld} from 'test-module';
You are specifically importing a member of 'test-module' named 'helloWorld' and not the default export. In this case, it is the function 'helloWorld'.
If you had done:
import {something} from 'test-module';
The 'something' would be 'undefined' since there is no export for with that name.
import * as something from 'test-module';
is asking for an object with all of the named exports of 'test-module'.
Then you can access any of the exports in 'test-module' as something.name. In this case they will be something.default and something.helloWorld.

Answer 2

import * as CodeMirror from 'codemirror' imports all the named exports and namespaces them into an object called CodeMirror.
import CodeMirror from 'codemirror' imports the default export.