@signalk/nmea0183-signalk/test/HDG.js

A node.js/javascript parser for NMEA0183 sentences. Sentences are parsed to Signal K format.

/**
 * Copyright 2016 Signal K <info@signalk.org> and contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

const Parser = require('../lib')
const chai = require('chai')
const should = chai.Should()

chai.use(require('chai-things'))

describe('HDG', () => {
  it('Converts OK using individual parser', () => {
    const delta = new Parser().parse('$SDHDG,181.9,,,0.6,E*32')
    delta.updates[0].values.should.contain.an.item.with.property(
      'path',
      'navigation.headingMagnetic'
    )
    delta.updates[0].values[0].value.should.be.closeTo(
      (181.9 / 180) * Math.PI,
      0.005
    )
    delta.updates[0].values.should.contain.an.item.with.property(
      'path',
      'navigation.magneticVariation'
    )
    delta.updates[0].values
      .find((pv) => pv.path === 'navigation.magneticVariation')
      .value.should.be.closeTo((0.6 / 180) * Math.PI, 0.005)
  })

  it('Sentence with just heading works', () => {
    const delta = new Parser().parse('$HCHDG,51.5,,,,*73')

    delta.updates[0].values.should.contain.an.item.with.property(
      'path',
      'navigation.headingMagnetic'
    )
    delta.updates[0].values[0].value.should.be.closeTo(
      (51.5 / 180) * Math.PI,
      0.005
    )
  })

  it('Sentence with all fields converts and applies corrections', () => {
    const delta = new Parser().parse('$INHDG,180,5,W,10,W*6D')

    delta.updates[0].values
      .find((pv) => pv.path === 'navigation.headingMagnetic')
      .value.should.be.closeTo(((180 - 5) / 180) * Math.PI, 0.00001)
    delta.updates[0].values
      .find((pv) => pv.path === 'navigation.headingCompass')
      .value.should.be.closeTo((180 / 180) * Math.PI, 0.00001)
    delta.updates[0].values
      .find((pv) => pv.path === 'navigation.magneticVariation')
      .value.should.be.closeTo((-10 / 180) * Math.PI, 0.00001)
    delta.updates[0].values
      .find((pv) => pv.path === 'navigation.magneticDeviation')
      .value.should.be.closeTo((-5 / 180) * Math.PI, 0.00001)
    delta.updates[0].values
      .find((pv) => pv.path === 'navigation.headingTrue')
      .value.should.be.closeTo(((180 - 5 - 10) / 180) * Math.PI, 0.00001)
  })

  it("Doesn't choke on empty sentences", () => {
    const delta = new Parser().parse('$SDHDG,,,,,*70')
    should.equal(delta, null)
  })
})