catdad/grandma

#!/usr/bin/env node
/* eslint-disable no-console */

var path = require('path');

var BASE = process.cwd();
var NAME = 'grandma';
var CLI = path.posix.join('bin', 'cli.js');

function tryRequire(route) {
    try {
        // Resolve will throw if the module does not exist.
        route = require.resolve(route);
    } catch(e) {
        return false;
    }

    // Do not try/catch the actual require. If the module itself actually
    // throws, we still want to see that error.
    require(route);
    return true;
}

// Require the local version of grandma
function requireLocal() {
    var resolvedUri = path.posix.join(BASE, 'node_modules', NAME, CLI);
    return tryRequire(resolvedUri);
}

// This is requiring the package at the current root (cwd), assuming
// that the user is me actually developing grandma.
function requireDev() {
    // If we are not in this super-special env, move on.
    if (process.env.NODE_ENV !== 'dev-test') {
        return false;
    }

    var resolvedUri = path.posix.join(BASE, CLI);
    return tryRequire(resolvedUri);
}

// We did not find grandma installed locally, nor are we
// executing in the grandma folder itself (which might happen
// during development), so we will use the global one instead.
function continueWithCurrent() {
    var resolvedUri = './cli.js';
    return tryRequire(resolvedUri);
}

var done = false;

[
    requireLocal,
    requireDev,
    // TODO: consider not doing this at all, forcing the user
    // to always install locally.
    continueWithCurrent
].forEach(function(func) {
    done = done || !!func();
});

if (!done) {
    console.error(
        'FATAL: %s %s\n%s',
        NAME, 'module was not found.',
        'Run "npm install grandma" to install the module locally'
    );

    process.exit(1);
}