serialine/consola

🐨 Elegant Console Logger for Node.js and Browser

🐨 Consola

Elegant Console Wrapper

Why Consola?

👌  Easy to use
💅  Fancy output with fallback for minimal environments
🔌  Pluggable reporters
💻  Consistent command line interface (CLI) experience
🏷  Tag support
🚏  Redirect console and stdout/stderr to consola and easily restore redirect.
🌐  Browser support
⏯  Pause/Resume support
👻  Mocking support
👮‍♂️  Spam prevention by throttling logs
❯  Interactive prompt support powered by clack

Installation

Using npm:

npm i consola

Using yarn:

yarn add consola

Using pnpm:

pnpm i consola

Getting Started

// ESM
import { consola, createConsola } from "consola";

// CommonJS
const { consola, createConsola } = require("consola");

consola.info("Using consola 3.0.0");
consola.start("Building project...");
consola.warn("A new version of consola is available: 3.0.1");
consola.success("Project built!");
consola.error(new Error("This is an example error. Everything is fine!"));
await consola.prompt("Deploy to the production?", {
  type: "confirm",
});

Will display in the terminal:

You can use smaller core builds without fancy reporter to save 80% of the bundle size:

import { consola, createConsola } from "consola/basic";
import { consola, createConsola } from "consola/browser";
import { createConsola } from "consola/core";

Consola Methods

<type>(logObject) <type>(args...)

Log to all reporters.

Example: consola.info('Message')

await prompt(message, { type })

Show an input prompt. Type can either of text, confirm, select or multiselect.

See examples/prompt.ts for usage examples.

addReporter(reporter)

• Aliases: add

Register a custom reporter instance.

removeReporter(reporter?)

• Aliases: remove, clear

Remove a registered reporter.

If no arguments are passed all reporters will be removed.

setReporters(reporter|reporter[])

Replace all reporters.

create(options)

Create a new Consola instance and inherit all parent options for defaults.

withDefaults(defaults)

Create a new Consola instance with provided defaults

withTag(tag)

• Aliases: withScope

Create a new Consola instance with that tag.

wrapConsole() restoreConsole()

Globally redirect all console.log, etc calls to consola handlers.

wrapStd() restoreStd()

Globally redirect all stdout/stderr outputs to consola.

wrapAll() restoreAll()

Wrap both, std and console.

console uses std in the underlying so calling wrapStd redirects console too. Benefit of this function is that things like console.info will be correctly redirected to the corresponding type.

pauseLogs() resumeLogs()

• Aliases: pause/resume

Globally pause and resume logs.

Consola will enqueue all logs when paused and then sends them to the reported when resumed.

mockTypes

• Aliases: mock

Mock all types. Useful for using with tests.

The first argument passed to mockTypes should be a callback function accepting (typeName, type) and returning the mocked value:

consola.mockTypes((typeName, type) => jest.fn());

Please note that with the example above, everything is mocked independently for each type. If you need one mocked fn create it outside:

const fn = jest.fn();
consola.mockTypes(() => fn);

If callback function returns a falsy value, that type won't be mocked.

For example if you just need to mock consola.fatal:

consola.mockTypes((typeName) => typeName === "fatal" && jest.fn());

NOTE: Any instance of consola that inherits the mocked instance, will apply provided callback again. This way, mocking works for withTag scoped loggers without need to extra efforts.

Custom Reporters

Consola ships with 3 built-in reporters out of the box. A fancy colored reporter by default and fallsback to a basic reporter if running in a testing or CI environment detected using unjs/std-env and a basic browser reporter.

You can create a new reporter object that implements { log(logObject): () => { } } interface.

Example: Simple JSON reporter

import { createConsola } from "consola";

const consola = createConsola({
  reporters: [
    {
      log: (logObj) => {
        console.log(JSON.stringify(logObj));
      },
    },
  ],
});

// Prints {"date":"2023-04-18T12:43:38.693Z","args":["foo bar"],"type":"log","level":2,"tag":""}
consola.log("foo bar");

Log Level

Consola only shows logs with configured log level or below. (Default is 3)

Available log levels:

• 0: Fatal and Error
• 1: Warnings
• 2: Normal logs
• 3: Informational logs, success, fail, ready, start, ...
• 4: Debug logs
• 5: Trace logs
• -999: Silent
• +999: Verbose logs

You can set the log level by either:

• Passing level option to createConsola
• Setting consola.level on instance
• Using the CONSOLA_LEVEL environment variable (not supported for browser and core builds).

Log Types

Log types are exposed as consola.[type](...) and each is a preset of styles and log level.

A list of all available built-in types is available here.

Creating a new instance

Consola has a global instance and is recommended to use everywhere. In case more control is needed, create a new instance.

import { createConsola } from "consola";

const logger = createConsola({
  // level: 4,
  // fancy: true | false
  // formatOptions: {
  //     columns: 80,
  //     colors: false,
  //     compact: false,
  //     date: false,
  // },
});

Integrations

With jest or vitest

describe("your-consola-mock-test", () => {
  beforeAll(() => {
    // Redirect std and console to consola too
    // Calling this once is sufficient
    consola.wrapAll();
  });

  beforeEach(() => {
    // Re-mock consola before each test call to remove
    // calls from before
    consola.mockTypes(() => jest.fn());
  });

  test("your test", async () => {
    // Some code here

    // Let's retrieve all messages of `consola.log`
    // Get the mock and map all calls to their first argument
    const consolaMessages = consola.log.mock.calls.map((c) => c[0]);
    expect(consolaMessages).toContain("your message");
  });
});

With jsdom

{
  virtualConsole: new jsdom.VirtualConsole().sendTo(consola);
}

License

MIT