@homer0/simple-logger

💬 Simple logger

A small service to log messages in the console.

🍿 Usage

⚠️ This package is only for Node.

• ⚙️ Examples
• 🤘 Development

⚙️ Example

Logging messages

import { simpleLogger } from '@homer0/simple-logger';

const logger = simpleLogger();

logger.log('Starting the app');
// Will log the message the same way `console.log` would.

if (usingExperimentalFeature()) {
  logger.warn('WARNING: This feature is experimental');
  // Will log a yellow message.
}

if (onDevelopment()) {
  logger.info('Running on a development environment');
  // Will log a gray message.
}

if (loadConfiguration()) {
  logger.success('The configuration was successfully loaded');
  // Will log a green message
}

try {
  methodThatMayThrowAnError();
} catch (error) {
  logger.error('Damn it!', error);
  // Will log `Damn it!` on red, and the `error` stack trace information on `gray`.
}

Colored messages

This was demonstrated on the example above:

1. success(message) will log a green message.
2. warn(message) will log a yellow message.
3. error(message) will log a red message.
4. info(message) will log a gray message.

But they all depend on this method: log(message, color); it allows you to specify one of the colors available on the colors package.

By default, it uses the console default text color, but you can specify a different color for the message.

logger.log('Starting the app', 'green');

Multiple messages at once

All the methods support both a single message or an Array of them:

logger.info(['App running', 'connection detected', 'starting Skynet...']);
// This will log three gray messages.

You can even specify a color for each message:

logger.success([
  'It works!',
  ['wait, something is happening', 'gray'],
  'Nevermind, Skynet is up and running!',
]);
// This will log the first and third message on green and the second one on gray.

Prefixing the messages

When creating the logger, you can specify a prefix option that will be prepended to each message.

const logger = simpleLogger({ prefix: 'my-app' });
logger.log('Starting the app');
// Will log `[my-app] Starting the app`

Date and time

The same way you can specify the prefix when creating the logger, you also have a showTime option that will make the logger show the current date and time on each message.

const logger = simpleLogger({ showTime: true });
logger.log('Starting the app');
// Will log something like `[2022-06-25 19:41:11] Starting the app`

Yes, you can use both prefix and showTime together.

Jimple provider

If your app uses a Jimple container, you can register SimpleLogger as the simpleLogger service by using its provider:

import { simpleLoggerProvider } from '@homer0/simple-logger';

// ...

container.register(simpleLoggerProvider);

// ...

const logger = container.get('simpleLogger');

And since the provider is a "provider creator" (created with my custom version of Jimple), you can customize its service name:

container.register(
  simpleLoggerProvider({
    serviceName: 'myLogger',
  }),
);

App logger provider

The package has an alternative service provider for Jimple that gets the project name from the package.json and uses as the prefix:

import { appLoggerProvider } from '@homer0/simple-logger';

// ...

container.register(appLoggerProvider);

// ...

const logger = container.get('appLogger');
logger.log('Starting the app');
// Will log `[my-app] Starting the app`, where `my-app` is the `name` in
// your package.json

You can also specify a appLoggerPrefix on your package.json, and it will use that instead of the name.

Dependencies

The "app logger provider" depends on the following services, and it will try to find them in the container, otherwise, it will create new instances:

• @homer0/package-info, with the name packageInfo. Used to get the project's package.json information.
• @homer0/path-utils, with the name pathUtils. Needed by package-info to generate the paths relative to the project root.

If you already implement the dependencies, but with a different name, you can specify them in the provider:

container.register(
  appLoggerProvider({
    services: {
      packageInfo: 'myPackageInfo',
      pathUtils: 'myPathUtils',
    },
  }),
);

🤘 Development

As this project is part of the packages monorepo, it requires Yarn, and some of the tooling, like ESLint and Husky, are installed on the root's package.json.

Yarn tasks

Task	Description
test	Runs the unit tests.
build	Bundles the project.