Automatic generated require.ensure() wrapper

[pksjce]

From @cowwoc on January 28, 2015 23:52

Looking at the require.ensure() code found at https://github.com/webpack/docs/wiki/code-splitting, is there a tool that will automatically generate a require.ensure() wrapper on behalf of the user?

Meaning, given:

var a = require("module-a");
var b = require("module-b");

the tool would scan for require() statements, and generate the following output.js:

require.ensure(["module-a", "module-b"], function(require) {
    var a = require("module-a");
    var b = require("module-b");
});

This way, the end-user codes in terms of simple synchronous require() and webpack generates the correct bundles with asynchronous loads under the hood.

Copied from original issue: webpack/webpack#734

[pksjce]

From @sirlancelot on January 29, 2015 1:15

Webpack does it automatically, you can write require.ensure([], function() { var a = require("module-a") }) and it will work just fine.

[pksjce]

From @cowwoc on January 29, 2015 1:18

Excellent. Please add this to the documentation (ideally on https://github.com/webpack/docs/wiki/code-splitting).

On a sidenote, is it possible to omit require.ensure() altogether and have Webpack add that? In other words, what is the significance of the user adding this code himself/herself? Does it denote something to Webpack?

[pksjce]

From @sirlancelot on January 29, 2015 3:20

You have to tell webpack where to split the bundle.

[pksjce]

From @cowwoc on January 29, 2015 4:42

@sirlancelot Okay. Why/when would users want to populate the dependencies array of require.ensure() manually (instead of leaving it empty)? Is there a legitimate use-case for doing so?

[sirlancelot]

I would imagine pre-populating the require.ensure array is for when you have deeply nested/split bundles and you want to tell webpack that certain modules should go in to a certain bundle. You would pre-populate the require.ensure array for the same scenarios you would use require.include; it just includes it in the bundle without evaluating it.

[SpaceK33z]

This would be covered by #3.