I have identified the following import statements in node. Do all the statements below import mathgraph with a different namespace scope, or which import styles are identical?
const/var/let mathgraph = require('mathgraph');
import * as mathgraph from 'mathgraph';
import mathgraph from 'mathgraph';
import { mathgraph } from 'mathgraph';
import mathgraph = require('mathgraph');
// mathgrab lib
export default { foo: 'foo' }
// your code
import mathgraph from 'mathgraph';
mathgrab.foo
This imports the default export.
// mathgrab lib
export const someObject = { foo: 'foo' }
// your code
import { someObject } from 'mathgraph';
someObject.foo
This imports a named export.
// mathgrab lib
export const someObject = { foo: 'foo' }
export default { bar: 'bar' }
// your code
import mathgraph, { someObject } from 'mathgraph';
mathgrab.someObject.foo
mathgrab.default.bar
You can even combine these two to import both kinds of exports in one line.
// mathgrab lib
export const someObject = { foo: 'foo' }
export default { bar: 'bar' }
// your code
import * as mathgraph from 'mathgraph';
mathgrab.someObject.foo
mathgrab.default.bar
This imports all exports as a single object. The default export will be on the default property of this object.
const mathgraph = require('mathgraph');
This only works in node, and is functionally the same as import *, but it's a dynamic runtime require, rather than than a compile time import. That means that typescript can't use the types of the imported file. require is just a function, so it returns a value of type any, thereby missing out on all typing info.
Don't use require with typescript, you pretty always want to use import instead.
import mathgraph = require('mathgraph');
And lastly, this is invalid syntax. So don't do that.