callback-coordination.test.js

/*
 * Copyright Elasticsearch B.V. and other contributors where applicable.
 * Licensed under the BSD 2-Clause License; you may not use this file except in
 * compliance with the BSD 2-Clause License.
 */

'use strict';
const tape = require('tape');
const logging = require('../../lib/logging');

const logger = logging.createLogger('off');

const {
  CallbackCoordination,
} = require('../../lib/cloud-metadata/callback-coordination');
tape.test('fetch coordination: all successful', function (t) {
  const fetcher = new CallbackCoordination(-1, logger);
  fetcher.schedule(function (fetcher) {
    setTimeout(function () {
      fetcher.recordResult(null, 'pass1');
    }, 10);
  });

  fetcher.schedule(function (fetcher) {
    setTimeout(function () {
      fetcher.recordResult(null, 'pass2');
    }, 20);
  });

  fetcher.schedule(function (fetcher) {
    setTimeout(function () {
      fetcher.recordResult(null, 'pass3');
    }, 30);
  });

  fetcher.schedule(function (fetcher) {
    setTimeout(function () {
      fetcher.recordResult(new Error('an error'));
    }, 200);
  });

  fetcher.on('result', function (result) {
    t.equals('pass1', result, "first callback's value is the result");
    t.end();
  });

  fetcher.on('error', function () {
    t.fail('no errors expected');
  });
  fetcher.start();
});

tape.test('fetch coordination: all errors', function (t) {
  const fetcher = new CallbackCoordination(-1, logger);
  fetcher.schedule(function (fetcher) {
    setTimeout(function () {
      fetcher.recordResult(new Error('an error'));
    }, 10);
  });

  fetcher.schedule(function (fetcher) {
    setTimeout(function () {
      fetcher.recordResult(new Error('an error'));
    }, 20);
  });

  fetcher.schedule(function (fetcher) {
    setTimeout(function () {
      fetcher.recordResult(new Error('an error'));
    }, 30);
  });

  fetcher.on('result', function (result) {
    t.fail('no results');
  });

  fetcher.on('error', function (error) {
    t.ok(error);
    t.equals(error.allErrors.length, 3, 'all three errors captured');
    t.end();
  });
  fetcher.start();
});

tape.test(
  'fetch coordination: fails to invoke callback (timeout)',
  function (t) {
    const fetcher = new CallbackCoordination(100, logger);
    fetcher.schedule(function (fetcher) {
      setTimeout(function () {
        fetcher.recordResult(new Error('an error'));
      }, 10);
    });

    fetcher.schedule(function (fetcher) {
      setTimeout(function () {
        fetcher.recordResult(new Error('an error'));
      }, 20);
    });

    fetcher.schedule(function (fetcher) {
      setTimeout(function () {
        // Deliberately empty — simulates forgetting to call fetcher.recordResult
      }, 30);
    });

    fetcher.on('result', function (result) {
      t.error('do no expect to reach');
    });

    fetcher.on('error', function (error) {
      t.ok(error);
      t.equals(error.allErrors.length, 2, 'two of three errors captured');
      t.equals(error.message, 'callback coordination reached timeout');
      t.end();
    });
    fetcher.start();
  },
);