The module property is undefined when using vm.runInThisContext

Question

Here is a function from jasmine 2.0.0 standalone project:

function getJasmineRequireObj() {
    if (typeof module !== "undefined" && module.exports) {
        return exports;
    } else {
        window.jasmineRequire = window.jasmineRequire || {};
        return window.jasmineRequire;
    }
}

I guess that if I would use the standard require method the module property will be define. When I load this file using the VM module as follows the module global property is undefined:

var fs = require('fs');
var vm = require('vm');
var jasmineFile = fs.readFileSync(__dirname + '/jasmine.js');
vm.runInThisContext(src, jasmineFile);

Is this the expected behavior of the VM module or a defect?

Answer 1

It is the expected behaviour. Your code is evaluated in the same context, but not in the same scope, so module, exports and whatnot are undefined. You can do something like this:

var m = require('module')
var src = 'module.exports = 42'
var res = require('vm').runInThisContext(m.wrap(src))(exports, require, module, __filename, __dirname)
console.log(module.exports)

but there is no much point in doing that, because it's basically what require does