nes-emu/ppu/registers/PPUAddr.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 = 0x2006;
describe("CPU/PPU registers interaction", () => {
  describe("PPUAddr", () => {
    let ppu, memory, register;
    beforeEach(() => {
      ({
        ppu,
        memory
      } = (0, _createTestContext.default)());
      register = ppu.registers.ppuAddr;
    });
    it("is write-only", () => {
      register.setValue(123);
      memory.readAt(ADDRESS).should.equal(0);
    });
    it("writes the MSB first, then the LSB", () => {
      memory.writeAt(ADDRESS, 0x12);
      memory.writeAt(ADDRESS, 0x24);
      register.address.should.equal(0x1224);
    });
  });
});