test.js

'use strict';
const assert = require('assert');
const finanzamt = require('.');

it('returns information about the Finanzamt Prenzlauer Berg', () => {
  assert.deepStrictEqual(finanzamt('1131'), {
    buFaNr: '1131',
    name: 'Prenzlauer Berg',
    hausanschrift: {
      strasse: 'Storkower Straße',
      hausNr: '134',
      plz: '10407',
      ort: 'Berlin'
    },
    tel: '030 9024-28 0',
    url: 'http://www.berlin.de/sen/finanzen'
  });
});

it('returns information when steuernummer is given', () => {
  assert.strictEqual(finanzamt('1121081508150').name, 'Tempelhof');
});

it('returns no hausanschrift.hausNr property if there is none', () => {
  assert(
    !Object.prototype.hasOwnProperty.call(
      finanzamt('1020').hausanschrift,
      'hausNr'
    )
  );
});

it('returns no hausanschrift.hausNrZusatz property if there is none', () => {
  assert(
    !Object.prototype.hasOwnProperty.call(
      finanzamt('1010').hausanschrift,
      'hausNrZusatz'
    )
  );
});

it('returns no fax property if there is none', () => {
  assert(!Object.prototype.hasOwnProperty.call(finanzamt('1115'), 'fax'));
});

it('returns no mail property if there is none', () => {
  assert(!Object.prototype.hasOwnProperty.call(finanzamt('2801'), 'mail'));
});

it('returns no url property if there is none', () => {
  assert(!Object.prototype.hasOwnProperty.call(finanzamt('2111'), 'url'));
});

it('returns undefined if Finanzamt can’t be found', () => {
  assert.strictEqual(finanzamt('0000'), undefined);
});

it('throws an error if bundesfinanzamtsnummer is not 4 characters long', () => {
  assert.throws(() => finanzamt('1'), {
    name: 'TypeError',
    message:
      '`bundesfinanzamtsnummer` or `steuernummer` must be 4 or 13 characters long respectively'
  });
});

it('throws an error if steuernummer is not 13 characters long', () => {
  assert.throws(() => finanzamt('21/815/08150'), {
    name: 'TypeError',
    message:
      '`bundesfinanzamtsnummer` or `steuernummer` must be 4 or 13 characters long respectively'
  });
});

it('throws an error if input is not a string', () => {
  assert.throws(() => finanzamt(1131), {
    name: 'TypeError',
    message: '`bundesfinanzamtsnummer` or `steuernummer` must be a string'
  });
});