bahmutov/really-need

Node require wrapper with options for cache busting, pre- and post-processing

really-need's Issues

Problem in basic usage

Hello, thanks a lot for this library.

I am evaluating it to see if I could use for a mutation testing library I am writing, I've setup a basic scenario to see how it works:

// source.js
var lib = {};

lib.fn = function() {
  return true;
};

module.exports = lib;

// test.js
describe('fn', function() {

  var lib = require('./source'),
      expect = require('chai').expect;

  it('returns true', function() {
    expect(lib.fn()).to.be.true;
  });

});

// runner.js
require = require('really-need');
var foo = require('./test', {
  pre: function (source, filename) {
    return source;
  }
});

When I run it it gives me an error, it's quite long, I'll paste what I think it's relevant (here the whole thing https://gist.github.com/lazywithclass/93898774a3644be63c32)

patched compile has crashed
internalModule is not defined
ReferenceError: internalModule is not defined
    at Module.eval (eval at <anonymous> (/Users/lazywithclass/workspace/mutagen/node_modules/really-need/index.js:230:25), <anonymous>:30:19)
    at Module._compile (/Users/lazywithclass/workspace/mutagen/node_modules/really-need/index.js:251:29)
    at load (/Users/lazywithclass/workspace/mutagen/node_modules/really-need/index.js:73:12)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at loadRealModule (/Users/lazywithclass/workspace/mutagen/node_modules/really-need/index.js:133:23)
    at Module.reallyNeedRequire [as require] (/Users/lazywithclass/workspace/mutagen/node_modules/really-need/index.js:181:16)
    at Object.<anonymous> (/Users/lazywithclass/workspace/mutagen/test/mutation-true-false/mutator.js:24:11)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)

I am running node 4.3.1and really-need 1.9.2.

Any hint / help would be greatly appreciated.

UPDATE: Using node 4.2.2 and fake seems to solve the issue... but still I am looking at your code to understand how can I use it with newer versions.

Overwrite require() in a project but exclude node_modules

I'm thinking about ways one might incorporate ramda-t in development process without too much hassle.

One of those I've considered is conditionally overwriting require in non-production environment so that if you require('ramda') instead of vanilla Ramda you'd get ramda-t.

In order for this to be a feasible approach, the require overwrite should only apply to the project's own files.

I know based on the README that really-need can be used to overwrite require in the way I described, but I also understood that it would apply to global scope and affecting all dependencies as well.

Confirm native modules, like path still work

Configure default options at time require is replaced

Looking for a way to pass default options, applied to all require invocations (unless overridden by per-invocation options). So, I'd like to do things like this:

require = require('really-need')({... some default options...})

and then later on, in any given module:

var mymodule = require("mymodule")

where since I haven't supplied an options object, the defaults specified when I required really-need would be used.

great project btw, very innovative.

Can we pass arguments to the module on load and compile?

Overwrite wrap string

Add ability to insert non-existing module

With fake filename that does not resolve to anything.

require.cache['fake name'] = 'hi';
// somehow fake Function.Module._resolveFilename to accept loading 'fake name'
// the value is already in the cache

Check published size

Use guide http://glebbahmutov.com/blog/smaller-published-NPM-modules/

Separate cache from bust cache API arguments

bust - remove copy from cache before loading (false by default)
cache (true by default) - remove copy from cache after loading

Grunt file with linting

jshint / eslint / jscs, take settings from next-updater

Expose the cache object

Seems we do not give access to the underlying cache object

require = require('really-need');
Object.keys(require.cache).forEach(function (name) {
    delete require.cache[name];
});
TypeError: Object.keys called on non-object

Asynchronous pre hook

Hello, awesome module!

I have a requirement and wanted to check in with you before making a pr. Would you be willing to have the pre function below also accept a promise as its return value?

pre: function (source, filename) {
    // transform the source before compiling it
    return source;
},

Seems to conflict with describe-it

Describe-it https://github.com/bahmutov/describe-it seems to try to overwrite the require again. Need to detect and avoid multiple overwrites

Test against every node version using autochecker

Use https://github.com/VictorBjelkholm/autochecker to test every available Node version

Allow fake compiled code

In addition to fake source, allow passing compiled code directly, objects, primitives and functions

var result = require('fake-module', {
  fake: { foo: 42 }
});
// result is {foo: 42}

Can really-need be used to spy on the loaded modules?

Instrument the loaded modules?

Setup commit message validation

https://gist.github.com/bahmutov/a15d49b3fe503fb546fb

Add post-processing function

Should transform compiled object (exported) before putting it into the cache

var q = require('q', {
  post: function (q) {
   q.longStackSupport = true;
   return q;
  }
});

if function returns undefined, keep original exported object.

Setup dont-break testing

Do not break dependencies.

Possible test failure: ReferenceError: resolvedArgv is not defined

I was noticing an error in my own project, so I cloned really-need and ran the tests, but am seeing errors such as this:

ReferenceError: resolvedArgv is not defined
at Module.eval (eval at (/home/sbasu/workspace-idea/really-need/index.js:115:45), :68:10)
at Module._compile (/home/sbasu/workspace-idea/really-need/index.js:127:31)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:364:17)
at Module.reallyNeedRequire as require
at require (module.js:380:17)
at Object. (/home/sbasu/workspace-idea/really-need/test/simple.js:8:11)
at Module._compile (module.js:456:26)

Essentially the eval'ed version of Module's _compile is failing due to the resolvedArg being undefined. As far as I can tell, the original _compile knows about this var because it's declared in the scope that _compile is. But when _compile is replaced, this isn't the case anymore looks like.

This is using Node 0.10.33, and the error above is if I just run the simple.js test.

shebangRe reference error on Node v5.1

> node some_file.js

undefined:4
  content = content.replace(shebangRe, '');
                            ^

ReferenceError: shebangRe is not defined
    at Module.eval (eval at <anonymous> (/Users/some_user/some_dir/some_project/node_modules/really-need/index.js:144:45), <anonymous>:4:29)
    at Module._compile (/Users/some_user/some_dir/some_project/node_modules/really-need/index.js:156:31)
    at load (/Users/some_user/some_dir/some_project/node_modules/really-need/index.js:67:12)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:313:12)
    at Module.reallyNeedRequire [as require] (/Users/some_user/some_dir/some_project/node_modules/really-need/index.js:105:23)
    at Object.<anonymous> (/Users/some_user/some_dir/some_project/some_file.js:6:30)
    at Module._compile (module.js:425:26)
    at Object.Module._extensions..js (module.js:432:10)
    at Module.load (module.js:356:32)

Turns out shebangRe is pretty fresh, was introduced by Node v5.1.0
See diff here: nodejs/node@5c54fa0

Went back to Node v4.2.2 and v5.0.0 to verify, both worked fine.

Can we pass data from the file to the loader via args?

Can args have an object where the code is writing data to?

// foo.js
(function reallyPrivate() {
  function getFoo() {
    return 'foo';
  }
  if (typeof test === 'object') {
    // pass data outside
    test.exported.getFoo = getFoo;
  }
}());

from outside we could

// test.js
require = require('really-need');
var myObject = {};
require('./add.js', {
  args: {
    test: {
      exported: myObject
    }
  }
});
// hope that myObject.getFoo = getFoo from foo.js

Create really-need-test module

Separate npm module, then add .dont-break to really-need

Failing example with express server

See https://gist.github.com/adammcarth/5490b7cb77fc2c1eae42
from https://gist.github.com/adammcarth

// route_tests.js
module.exports = function(server) {
    var request = require("supertest");

    it("[GET] /", function(done) {
        request(server).get("/").expect(200, done);
    });

    it("[GET] /posts", function(done) {
        request(server).get("/posts").expect(200, done);
    });
}

// run.js
// Runs the my-app testing suite
var require = require("really-need");

describe("Running all My App tests:", function() {
    var server;

    beforeEach(function () {
        server = require("../server/server.js", { bustCache: true });
    });

    afterEach(function (done) {
        server.close(done);
    });

    describe("Check that all public routes are responding...", 
       require("route_tests.js")(server));
});

Use latest pre-git

with good commit message validation

Add verbose / debug option

print to console messages if require('really-need', { debug: true });

Improve `args` to support nested functions

Functions that aren't defined as top-level properties of args are not making through to the loaded module source. So for example, this works fine:

// another-require.js
require('something');

// index.js
require = require('really-need');
require('./another-require', {
  args: {
    require: function (name) {
      console.log('no requires allowed');
    }
  }
});
// prints "no requires allowed"

... but this doesn't:

// stuff-with-lodash.js
console.log( _.yam );
_.filter();

// index.js
require = require('really-need');
require('./stuff-with-lodash', {
  args: {
    _: {
      'yam': 678,
      'filter': function () {
        console.log('look! a fake lodash filter!');
      }
    }
  }
});
// prints:
// 678
// _.filter is not a function

I already hacked together something that works using a dusty gist by @cowboy but I'm not in love with it.
Let me know if this is something you think worth looking into.

Question: really-need vs proxyquire

How really-need differs from proxyquire?
They seem to be really similar in features. Any pros/cons using really-need over proxyquire?

Rename API option cache to keep

Keep cache as an alias

Show if can be used for mocking modules in unit tests

Does not work on Node 5.4

Seems the internal code has changed. Need to at least allow some features to work, like busting the require cache

Update travis list

Probably don't need iojs but need node 4 and 5

Add pre- processing function

Should transform loaded source code before compiling it

Setup semantic release

Can we disable parent for a required module

For example when loading one module from another, can we set parent to undefined?

// first.js
require('./second');
// second.js
console.log(module.parent); // prints first.js