export = foo;

import foo = require("./file");
// deprecated

export default foo;

import foo from "./file";

export foo;

or:

export {foo};

import {foo} from "./file";

export foo;
export bar;

or:

export {foo, bar};

import {foo, bar} from "./file";

or:

import * as Oops from "./file";
let foo = Oops.foo;
let bar = Oops.bar;

declare module "foo" {...};

import foo from "foo";

// Without relative path "./" in front,
// TypeScript compiler will look for
// an external module declaration.