-r/--require flag for npm modules

[wavded]

Given the following steps:

npm install heapdump
node -r heapdump file.js

I get the following error:

Error: Cannot find module 'heapdump'
    at Function.Module._resolveFilename (module.js:337:15)
    at Function.Module._load (module.js:287:25)
    at node.js:858:16
    at Array.forEach (native)
    at Function.startup.preloadModules (node.js:857:32)
    at startup (node.js:95:17)
    at node.js:963:3

My expectation was the module would be resolved the same way as if I were to do:

require('heapdump')

[ofrobots]

I'm investigating.

[ofrobots]

The problem is related to the fact that preload modules do not have a parent. Not even the main module. As such they don't use the .paths property from the parent which gives us a starting point for searching node_module directories.

[ofrobots]

Here's a potential fix I am evaluating:

Module.preloadModules = function(requests) {
  if (requests) {
    // Preloaded modules have a dummy parent module which is deemed to exist
    // in the current working directory. This seeds the search path for
    // preloaded modules.
    var parent = new Module('internal/preload', null);
    parent.paths = Module._nodeModulePaths(process.cwd());
    requests.forEach(function(request) {
      Module._load(request, parent, false);
    });
  }
}

Note the slight semantic difference between -r foo and require(foo). The former search from the working directory of the process upwards whereas the latter starts from the directory of the requiring module.

[i5ting]

the same issue

[i5ting]

i want in cli i can use require 'xxx'

[Fishrock123]

Note the slight semantic difference between -r foo and require(foo). The former search from the working directory of the process upwards whereas the latter starts from the directory of the requiring module.

Right, but that seems to make sense, the requiring "module" in this case is effectively the working directory.

[ofrobots]

@Fishrock123 That's my intuition too. I wanted to point it out to make sure it is not surprising to others.

[Fishrock123]

Fixed in 5759722!

[bmeck]

Using process.cwd() makes using preloaded modules with absolute paths blow up when you are in a ENOENT directory. investigating fix