index.js

const chalk = require('chalk');
const clear = require('clear');
const figlet = require('figlet');
const inquirer = require('inquirer');
const Utils = require('./lib/utils');

if (require.main === module) {
    (function () {
        clear();

        console.log(''); // prevents top from being chopped off

        console.log(
            chalk.yellow(
                figlet.textSync('CSV Generator', {
                    horizontalLayout: 'full'
                })
            )
        );

        console.log('To show help or list available functions, type "help" or "help functions" at any question and press ENTER');

        const help = input => {
            if (typeof input === 'string') {
                if (input.toLowerCase().trim() === 'help') {
                    return 'Testing...';
                } else if (/^(help\s*)?func(tions?)?$/i.test(input.toLowerCase().trim())) {
                    return 'Available functions:\n' + Utils.listFunctions(require('./functions'));
                }
            }

            return true;
        };

        inquirer.prompt([
            {
                name: 'file',
                type: 'input',
                message: 'Enter in the name of your output file:',
                default: 'my.csv',
                validate: function (input) {
                    let response = help(input);

                    if (response !== true) {
                        return response;
                    }

                    return true;
                }
            },
            {
                name: 'use-headers',
                type: 'list',
                message: 'Enable column headers?',
                choices: ['Yes', 'No']
            },
            {
                name: 'custom-headers',
                type: 'list',
                message: 'Specify custom column headers?',
                choices: ['Yes', 'No'],
                when: function (input) {
                    return input['use-headers'] === 'Yes';
                }
            },
            {
                name: 'headers',
                message: 'Enter column headers separated by a comma.',
                type: 'editor',
                when: function (input) {
                    return input['custom-headers'] === 'Yes';
                },
                validate: function (input) {
                    let headers = input.trim().split(/\s*,\s*/);

                    if (headers.length === 0) {
                        return 'Invalid column headers';
                    }

                    return true;
                }
            },
            {
                name: 'columns',
                type: 'input',
                message: 'Enter in column definitions using a list of available functions separated by a comma. For examples and other documentation, type "help" and press ENTER:',
                validate: function (input) {
                    let response = help(input);

                    if (response !== true) {
                        return response;
                    }

                    if (!input || (input && input.trim().split(/\s*,\s*/g).length === 0)) {
                        return 'Invalid column definitions.';
                    }

                    return true;
                }
            },
            {
                name: 'rows',
                type: 'input',
                message: 'Enter in the total number of rows to generate (e.g. 100, 100000, 100K, 10M, 1B, etc.):',
                default: 100,
                validate: function (input) {
                    let response = help(input);

                    if (response !== true) {
                        return response;
                    }

                    try {
                        Utils.convertNumber(input);
                    } catch (e) {
                        return 'Invalid number entered. Value must be an integer greater than 0.';
                    }

                    return true;
                }
            }
        ]).then(answers => {
            Utils.generate(answers.file, answers.columns.split(/\s*,\s*/), {
                rows: Utils.convertNumber(answers.rows),
                chunks: 1000,
                headers: answers['use-headers'] === 'Yes'
            }, Array.isArray(answers.headers) ? answers.headers.split(/\s*,\s*/) : []);
        });
    }());
} else {
    module.exports = require('./lib/generator');
}