nes-emu/cpu/instructions/checks.spec.js

A NES emulator

"use strict";

var _ = _interopRequireDefault(require("."));
var _createTestContext = _interopRequireDefault(require("../../helpers/createTestContext"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
const should = require("chai").Should();
describe("instructions", () => {
  describe("checks", () => {
    let cpu, context;
    beforeEach(() => {
      ({
        cpu,
        context
      } = (0, _createTestContext.default)());
    });
    describe("BIT", () => {
      [{
        mask: 0b01100101,
        value: 0b10011010,
        z: true,
        n: true,
        v: false
      }, {
        mask: 0b11100101,
        value: 0b01011010,
        z: false,
        n: false,
        v: true
      }].forEach(_ref => {
        let {
          mask,
          value,
          z,
          n,
          v
        } = _ref;
        it("sets the Z, N, and V flags with mask=0b".concat(mask.toString(2), " and value=0b").concat(value.toString(2)), () => {
          cpu.registers.a.value = mask;
          _.default.BIT.execute(context, value);
          cpu.flags.z.should.equal(z);
          cpu.flags.n.should.equal(n);
          cpu.flags.v.should.equal(v);
        });
      });
    });
    [{
      instruction: "CMP",
      register: "a",
      source: 10,
      value: 120,
      z: false,
      n: true,
      c: false
    }, {
      instruction: "CMP",
      register: "a",
      source: 112,
      value: 2,
      z: false,
      n: false,
      c: true
    }, {
      instruction: "CPX",
      register: "x",
      source: 100,
      value: 100,
      z: true,
      n: false,
      c: true
    }, {
      instruction: "CPY",
      register: "y",
      source: 240,
      value: 30,
      z: false,
      n: true,
      c: true
    }].forEach(_ref2 => {
      let {
        instruction,
        register,
        source,
        value,
        z,
        n,
        c
      } = _ref2;
      describe(instruction, () => {
        it("compares and sets the proper flags with ".concat(register, "=").concat(source, " and value=").concat(value), () => {
          cpu.registers[register].value = source;
          _.default[instruction].execute(context, value);
          cpu.flags.z.should.equal(z);
          cpu.flags.n.should.equal(n);
          cpu.flags.c.should.equal(c);
        });
      });
    });
  });
});