Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Lazy loaders not worked as suspected #25

Open
litmit opened this issue Dec 18, 2013 · 1 comment
Open

Lazy loaders not worked as suspected #25

litmit opened this issue Dec 18, 2013 · 1 comment

Comments

@litmit
Copy link

litmit commented Dec 18, 2013

Try this code (simulate index.js loaders)

test.js

var obj = {};

Object.defineProperties(obj, {

  'util': {
    get: function() {
      console.log('wrapper called');
      return obj.util = require('util');
    }
  },
});

obj.util.isArray([]);
obj.util.isArray("");

node test.js
Output:

wrapper called
wrapper called

I think this is behavior that was not suspected.

Moreover:
node --use-strict test.js
Output:

wrapper called

TypeError: Cannot set property util of #<Object> which has only a getter
    at Object.defineProperties.util.get (test.js:8:23)
    at Object.<anonymous> (test.js:13:4)
    at Module._compile (module.js:456:26)
    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 Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:902:3

Well working code snippet:
test.js

var obj = {};

Object.defineProperties(obj, {

  'util': {
    get: function() {
      console.log('wrapper called');
      delete obj.util;
      return obj.util = require('util');
    },
    configurable: true
  },
});

obj.util.isArray([]);
obj.util.isArray("");

Run the test:
node --use-strict test.js
Output:

wrapper called
@3rd-Eden
Copy link
Member

Great find, this indeed seems to cause some pointless overhead. We could just use https://github.com/observing/initialise for the lazyloading which just takes care of every need there would ever be.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants