bemusic/bemuse

const { Timing, Compiler } = require('../lib')
const { expect } = require('chai')

describe('Timing', function () {
  function case1() {
    return new Timing(120, [
      { type: 'bpm', beat: 3, bpm: 90 },
      { type: 'stop', beat: 4, stopBeats: 1 },
      { type: 'bpm', beat: 4, bpm: 180 },
    ])
  }

  it('should return beats where there are events', function () {
    const t = case1()
    expect(t.getEventBeats()).to.deep.equal([3, 4])
  })

  it('should convert beats to seconds', function () {
    const t = case1()
    expect(t.beatToSeconds(0)).to.be.closeTo(0, 1e-2)
    expect(t.beatToSeconds(1)).to.be.closeTo(0.5, 1e-2)
    expect(t.beatToSeconds(2)).to.be.closeTo(1, 1e-2)
    expect(t.beatToSeconds(3)).to.be.closeTo(1.5, 1e-2)
    expect(t.beatToSeconds(4)).to.be.closeTo(2.167, 1e-2)
    expect(t.beatToSeconds(5)).to.be.closeTo(2.833, 1e-2)
  })

  it('should allow getting BPM at beat', function () {
    const t = case1()
    expect(t.bpmAtBeat(0)).to.equal(120)
    expect(t.bpmAtBeat(3)).to.equal(90)
    expect(t.bpmAtBeat(4)).to.equal(180)
  })

  it('should convert seconds to beat', function () {
    const t = case1()
    expect(t.secondsToBeat(0.0)).to.be.closeTo(0, 1e-2)
    expect(t.secondsToBeat(0.5)).to.be.closeTo(1, 1e-2)
    expect(t.secondsToBeat(1.0)).to.be.closeTo(2, 1e-2)
    expect(t.secondsToBeat(1.5)).to.be.closeTo(3, 1e-2)
    expect(t.secondsToBeat(2.167)).to.be.closeTo(4, 1e-2)
    expect(t.secondsToBeat(2.2)).to.be.closeTo(4, 1e-2)
    expect(t.secondsToBeat(2.3)).to.be.closeTo(4, 1e-2)
    expect(t.secondsToBeat(2.4)).to.be.closeTo(4, 1e-2)
    expect(t.secondsToBeat(2.5)).to.be.closeTo(4, 1e-2)
    expect(t.secondsToBeat(2.833)).to.be.closeTo(5, 1e-2)
  })

  describe('.fromBMSChart', function () {
    it('should work with extbpm', function () {
      const chart = Compiler.compile('#BPM01 123.45\n#00108:01').chart
      const t = Timing.fromBMSChart(chart)
      expect(t.bpmAtBeat(5)).to.equal(123.45)
    })
  })
})