log4js-node/test/tap/appender-dependencies-test.js

const { test } = require('tap');

const categories = {
  default: { appenders: ['filtered'], level: 'debug' },
};

let log4js;
let recording;

test('log4js appender dependencies', (batch) => {
  batch.beforeEach((done) => {
    log4js = require('../../lib/log4js');
    recording = require('../../lib/appenders/recording');
    if (typeof done === 'function') {
      done();
    }
  });
  batch.afterEach((done) => {
    recording.erase();
    if (typeof done === 'function') {
      done();
    }
  });
  batch.test('in order', (t) => {
    const config = {
      categories,
      appenders: {
        recorder: { type: 'recording' },
        filtered: {
          type: 'logLevelFilter',
          appender: 'recorder',
          level: 'ERROR',
        },
      },
    };
    t.test('should resolve if defined in dependency order', (assert) => {
      assert.doesNotThrow(() => {
        log4js.configure(config);
      }, 'this should not trigger an error');
      assert.end();
    });
    const logger = log4js.getLogger('logLevelTest');
    logger.debug('this should not trigger an event');
    logger.error('this should, though');

    const logEvents = recording.replay();
    t.test('should process log events normally', (assert) => {
      assert.equal(logEvents.length, 1);
      assert.equal(logEvents[0].data[0], 'this should, though');
      assert.end();
    });
    t.end();
  });

  batch.test('not in order', (t) => {
    const config = {
      categories,
      appenders: {
        filtered: {
          type: 'logLevelFilter',
          appender: 'recorder',
          level: 'ERROR',
        },
        recorder: { type: 'recording' },
      },
    };
    t.test('should resolve if defined out of dependency order', (assert) => {
      assert.doesNotThrow(() => {
        log4js.configure(config);
      }, 'this should not trigger an error');
      assert.end();
    });
    const logger = log4js.getLogger('logLevelTest');
    logger.debug('this should not trigger an event');
    logger.error('this should, though');

    const logEvents = recording.replay();
    t.test('should process log events normally', (assert) => {
      assert.equal(logEvents.length, 1);
      assert.equal(logEvents[0].data[0], 'this should, though');
      assert.end();
    });
    t.end();
  });

  batch.test('with dependency loop', (t) => {
    const config = {
      categories,
      appenders: {
        filtered: {
          type: 'logLevelFilter',
          appender: 'filtered2',
          level: 'ERROR',
        },
        filtered2: {
          type: 'logLevelFilter',
          appender: 'filtered',
          level: 'ERROR',
        },
        recorder: { type: 'recording' },
      },
    };
    t.test(
      'should throw an error if if a dependency loop is found',
      (assert) => {
        assert.throws(() => {
          log4js.configure(config);
        }, 'Dependency loop detected for appender filtered.');
        assert.end();
      }
    );
    t.end();
  });
  batch.end();
});