source: trip-planner-front/node_modules/execa/lib/stdio.js@ 188ee53

'use strict';
const alias = ['stdin', 'stdout', 'stderr'];

const hasAlias = opts => alias.some(x => Boolean(opts[x]));

module.exports = opts => {
        if (!opts) {
                return null;
        }

        if (opts.stdio && hasAlias(opts)) {
                throw new Error(`It's not possible to provide \`stdio\` in combination with one of ${alias.map(x => `\`${x}\``).join(', ')}`);
        }

        if (typeof opts.stdio === 'string') {
                return opts.stdio;
        }

        const stdio = opts.stdio || [];

        if (!Array.isArray(stdio)) {
                throw new TypeError(`Expected \`stdio\` to be of type \`string\` or \`Array\`, got \`${typeof stdio}\``);
        }

        const result = [];
        const len = Math.max(stdio.length, alias.length);

        for (let i = 0; i < len; i++) {
                let value = null;

                if (stdio[i] !== undefined) {
                        value = stdio[i];
                } else if (opts[alias[i]] !== undefined) {
                        value = opts[alias[i]];
                }

                result[i] = value;
        }

        return result;
};