nes-emu/registers/InMemoryRegister.spec.js

A NES emulator

"use strict";

var _InMemoryRegister = _interopRequireDefault(require("./InMemoryRegister"));
var _memory = require("../memory");
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
const should = require("chai").Should();
describe("registers", () => {
  describe("InMemoryRegister", () => {
    let memory, register;
    beforeEach(() => {
      memory = _memory.WithCompositeMemory.createSegment([new _InMemoryRegister.default(),
      // byte 0
      new _InMemoryRegister.default(),
      // byte 1
      new _InMemoryRegister.default(),
      // byte 2
      register = new _InMemoryRegister.default() // byte 3
      .addField("booleanBit2", 2).addReadOnlyField("shortNumberBit5", 5, 2).addField("longNumberBit4", 4, 4)]);
    });
    it("allows reading subfields", () => {
      memory.writeAt(3, 0b01100100);
      register.booleanBit2.should.equal(1);
      register.shortNumberBit5.should.equal(0b11);
      register.longNumberBit4.should.equal(0b0110);
    });
    it("allows writing subfields", () => {
      register.booleanBit2 = 1;
      memory.readAt(3).should.equal(0b00000100);
      register.longNumberBit4 = 0b1101;
      memory.readAt(3).should.equal(0b11010100);
    });
  });
});