nes-emu/controller/PrimaryControllerPort.spec.js

A NES emulator

"use strict";

var _createTestContext = _interopRequireDefault(require("../helpers/createTestContext"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
const should = require("chai").Should();
const ADDRESS = 0x4016;
const A_LOT = 30;
describe("I/O registers interaction", () => {
  describe("Controller port 1", () => {
    let controllers, memory;
    beforeEach(() => {
      ({
        controllers,
        memory
      } = (0, _createTestContext.default)());
    });
    it("can read controller's input, one button at time", () => {
      controllers[0].update("BUTTON_DOWN", true);
      controllers[0].update("BUTTON_START", true);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(1);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(1);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(0);
    });
    it("returns 1 after 8 button reads", () => {
      for (let i = 0; i < 8; i++) memory.readAt(ADDRESS).should.equal(0);
      for (let i = 0; i < A_LOT; i++) memory.readAt(ADDRESS).should.equal(1);
    });
    it("resets the cursor to A when writing 1 to the strobe flag", () => {
      controllers[0].update("BUTTON_A", true);
      controllers[0].update("BUTTON_DOWN", true);
      controllers[0].update("BUTTON_START", true);
      memory.readAt(ADDRESS).should.equal(1);
      memory.readAt(ADDRESS).should.equal(0);
      memory.writeAt(ADDRESS, 1);
      for (let i = 0; i < A_LOT; i++) memory.readAt(ADDRESS).should.equal(1);
      controllers[0].update("BUTTON_A", false);
      for (let i = 0; i < A_LOT; i++) memory.readAt(ADDRESS).should.equal(0);
      controllers[0].update("BUTTON_A", true);
      memory.writeAt(ADDRESS, 0);
      memory.readAt(ADDRESS).should.equal(1);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(1);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(1);
      memory.readAt(ADDRESS).should.equal(0);
      memory.readAt(ADDRESS).should.equal(0);
    });
  });
});