How to use commander

// Error enhancements
program
 .option(
  '--show-error-stack [json|string]',
  'show JavaScript error stacks in the GraphQL result errors (recommended in development)',
 )
 .option(
  '--extended-errors <string>',
  "a comma separated list of extended Postgres error fields to display in the GraphQL result. Recommended in development: 'hint,detail,errcode'. Default: none",
  (option: string) => option.split(',').filter(_ => _),
 );

afterEach(done => {
  commander.options = [];
  delete commander.arg0;
  delete commander.arg1;
  delete commander.arg2;
  delete commander.arg3;
  delete commander.arg4;
  done();
 });

it('should fail in action as port is invalid', done => {
  commander.loadDefinitions(testDefinitions);
  expect(() => {
   commander.parse(['node', './CLI.spec.js', '--arg0', 'arg0Value'], {
    PROGRAM_ARG_0: 'arg0ENVValue',
    PROGRAM_ARG_1: 'arg1ENVValue',
    PROGRAM_ARG_2: 'hello',
   });
  }).toThrow('arg2 is invalid');
  done();
 });

program.on('--help', () => {
 console.log(`
Get started:

 $ postgraphile
 $ postgraphile -c postgres://localhost/my_db
 $ postgraphile --connection postgres://user:pass@localhost/my_db --schema my_schema --watch --dynamic-json
`);
 process.exit(0);
});

program
 .command('db:migrate')
 .action(function() {
  openConfig()

  var db = configuration.db(configuration)

  return db.migrate()
   .then(function () {
    console.log('The database was migrated')
    db.close()
    process.exit(0)
   })
   .catch(handleDbError)
 })

program
 .command('generate')
 .option('-t, --tables <tables>', 'Comma delimited list of tables to generate schema from', list)
 .description('Generate Cube.js schema from DB tables schema')
 .action(
  (options) => generateSchema(options).catch(e => displayError(e.stack || e, { dbType: options.dbType }))
 )
 .on('--help', () => {
  console.log('');
  console.log('Examples:');
  console.log('');
  console.log('  $ cubejs generate -t orders,customers');
 });

program.option("-s, --settings [settings]",
 "Overrides layout settings for given view types",
 (settings) => {
  const res = parseSettings(settings);

  if (res.error) {
   exitWithError(res.error);
  }

  return res.result;
 },
 {}
);

it('should load properly definitions from env', done => {
  commander.loadDefinitions(testDefinitions);
  commander.parse([], {
   PROGRAM_ARG_0: 'arg0ENVValue',
   PROGRAM_ARG_1: 'arg1ENVValue',
   PROGRAM_ARG_2: '3',
  });
  expect(commander.arg0).toEqual('arg0ENVValue');
  expect(commander.arg1).toEqual('arg1ENVValue');
  expect(commander.arg2).toEqual(3);
  expect(commander.arg4).toEqual('arg4Value');
  done();
 });

program
 .usage('<command> [options]')
 .on('--help', () => {
  console.log('');
  console.log('Use cubejs <command> --help for more information about a command.');
  console.log('');
 });

function addFlag(
 optionString: string,
 description: string,
 parse?: (option: string) => mixed,
): AddFlagFn {
 program.option(optionString, description, parse);
 return addFlag;
}

program
 .command('auth <token>')
 .description('Authenticate access to Cube Cloud')
 .action(
  (currentToken) => authenticate(currentToken)
   .catch(e => displayError(e.stack || e))
 )
 .on('--help', () => {
  console.log('');
  console.log('Examples:');
  console.log('');
  console.log('  $ cubejs auth eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJkZXBsb3ltZW50SWQiOiIxIiwidXJsIjoiaHR0cHM6Ly9leGFtcGxlcy5jdWJlY2xvdWQuZGV2IiwiaWF0IjoxNTE2MjM5MDIyfQ.La3MiuqfGigfzADl1wpxZ7jlb6dY60caezgqIOoHt-c');
  console.log('  $ cubejs deploy');
 });

program.on("--help", () => {
 console.log("");
 console.log("  Examples:".blue);
 console.log("");
 console.log("    $ xmysql -u username -p password -d databaseSchema".blue);
 console.log("");
});

program
 .command('deploy')
 .description('Deploy project to Cube Cloud')
 .action(
  (options) => deploy({ directory: process.cwd(), ...options })
   .catch(e => displayError(e.stack || e))
 )
 .on('--help', () => {
  console.log('');
  console.log('Examples:');
  console.log('');
  console.log('  $ cubejs deploy');
 });

it('should fail when passing an invalid arguement', done => {
  commander.loadDefinitions(testDefinitions);
  expect(() => {
   commander.parse([
    'node',
    './CLI.spec.js',
    './spec/configs/CLIConfigUnknownArg.json',
   ]);
  }).toThrow('error: unknown option myArg');
  done();
 });

it('should fail when too many apps are set', done => {
  commander.loadDefinitions(testDefinitions);
  expect(() => {
   commander.parse([
    'node',
    './CLI.spec.js',
    './spec/configs/CLIConfigFailTooManyApps.json',
   ]);
  }).toThrow('Multiple apps are not supported');
  done();
 });