Pretty REPL

An extension of the Node REPL (repl.REPLServer) that applies syntax highlighting as the user types.

How to use it

Install the package:

$ npm install --save pretty-repl

Use the package:

const repl = require('pretty-repl');

const options = {
    prompt: '→ '
};

repl.start(options);

options is an an object with the same options as repl.REPLServer.

Additionally, it's possible to pass an additional colorize property to the options object:

{
    colorize: function (str) {
        // str is the the string in input.
        // the function should return the string that has been colorized to output in the REPL.
    }
}

Known issues

• The implementation in Node.js versions 11 and 12, this module works by monkey-patching the Interface prototype (readline module). If you use readline (or a module that depends on it) somewhere else, you may want to test everything thoroughly. In theory, there should be no side effects.
• For Node.js versions older than 11, this module does nothing.

Credits

Pretty repl is inspired and includes code fragments from:

• https://github.com/nodejs/repl
• https://github.com/aantthony/node-color-readline