For example, this snipit from the nodejs typings

declare module "readline" {
  export function emitKeypressEvents(stream: NodeJS.ReadableStream, interface?: ReadLine): void;
}

Generates an externs file with this content, including the parameter named "interface".

/**
 * @param {?} stream
 * @param {?=} interface
 * @return {?}
 */
tsickle_declare_module.readline.emitKeypressEvents = function(stream, interface) {};

however, closure compiler then rejects this with

.../node.externs.js:3524: ERROR - Parse error. ')' expected
tsickle_declare_module.readline.emitKeypressEvents = function(stream, interface) {};

I was a little surprised that Typescript accepts this, but Chrome, Safari, and Firefox all accept this code so i'm assuming it's valid to use "interface" as a parameter name is javascript. I did file a closure compiler bug as well.

(function x(interface) { console.log(interface); })('test')