log4js-node/test/tap/configuration-test.js

const { test } = require('tap');
const sandbox = require('@log4js-node/sandboxed-module');
const realFS = require('fs');

const modulePath = 'some/path/to/mylog4js.json';
const pathsChecked = [];

let fakeFS = {};
let dependencies;
let fileRead;

test('log4js configure', (batch) => {
  batch.beforeEach((done) => {
    fileRead = 0;

    fakeFS = {
      realpath: realFS.realpath, // fs-extra looks for this
      ReadStream: realFS.ReadStream, // need to define these, because graceful-fs uses them
      WriteStream: realFS.WriteStream,
      read: realFS.read,
      closeSync: () => {},
      config: {
        appenders: {
          console: {
            type: 'console',
            layout: { type: 'messagePassThrough' },
          },
        },
        categories: {
          default: {
            appenders: ['console'],
            level: 'INFO',
          },
        },
      },
      readdirSync: (dir) => require('fs').readdirSync(dir),
      readFileSync: (file, encoding) => {
        fileRead += 1;
        batch.type(file, 'string');
        batch.equal(file, modulePath);
        batch.equal(encoding, 'utf8');
        return JSON.stringify(fakeFS.config);
      },
      statSync: (path) => {
        pathsChecked.push(path);
        if (path === modulePath) {
          return { mtime: new Date() };
        }
        throw new Error('no such file');
      },
    };

    dependencies = {
      requires: {
        fs: fakeFS,
      },
    };

    if (typeof done === 'function') {
      done();
    }
  });

  batch.test(
    'when configuration file loaded via LOG4JS_CONFIG env variable',
    (t) => {
      process.env.LOG4JS_CONFIG = 'some/path/to/mylog4js.json';

      const log4js = sandbox.require('../../lib/log4js', dependencies);

      t.notOk(log4js.isConfigured(), 'should not have configured');
      log4js.getLogger('test-logger');
      t.ok(log4js.isConfigured(), 'should be configured');

      t.equal(fileRead, 1, 'should load the specified local config file');

      delete process.env.LOG4JS_CONFIG;

      t.end();
    }
  );

  batch.test(
    'when configuration is set via configure() method call, return the log4js object',
    (t) => {
      const log4js = sandbox
        .require('../../lib/log4js', dependencies)
        .configure(fakeFS.config);
      t.type(
        log4js,
        'object',
        'Configure method call should return the log4js object!'
      );

      const log = log4js.getLogger('daemon');
      t.type(
        log,
        'object',
        'log4js object, returned by configure(...) method should be able to create log object.'
      );
      t.type(log.info, 'function');

      t.end();
    }
  );

  batch.end();
});