@airtasker/form-schema-compiler/src/tokenizers/createInputStream.test.js

a form schema compiler

import createInputStream from "./createInputStream";

test("createInputStream", () => {
  const stream = createInputStream("ab");
  expect(stream.eof()).toBeFalsy();

  expect(stream.peek()).toEqual("a");
  expect(stream.next()).toEqual("a");
  expect(stream.peek()).toEqual("b");
  expect(stream.next()).toEqual("b");

  expect(stream.eof()).toBeTruthy();
  expect(() => createInputStream()).toThrow();
});