index-hashify

A browserify plugin to replace numeric indexes with hashes.

The problem with numeric hashes

browserify uses numbers to identify module functions in the final bundle by default. Since modules are sorted according to their file paths, and those identification numbers are just their corresponding indexes in the sorted array (in most cases), they are prone to changing when dependencies inserted and deleted.

Suppose there are two modules '/a.js' and '/c.js', which will get 1 and 2 as their identification number in the final bundle, respectively. Now if we add require('/b.js') in 'a.js', '/c.js' will get 3 as its identification number even if nothing happens to the original module.

That may cause problems in some cases:

• common shared bundles. When using factor-bundle, the contents of the common bundle may change due to just the change of identification numbers, invalidating the application cache for it.
• hot module replacement. Tools like browserify-hmr replace changed modules, but not those who just suffer a identification number change, thus breaking the dependency chain. (See browserify-hmr#28)

This plugin will take the sha1 of the result of concating the file path (relative to basedir) with the contents of the module as the identification number instead, which will not change as long as the module keeps, thus fixing the above problems.

Usage

var b = browserify(opts)
var hashify = require('index-hashify')
b.plugin(hashify)
b.bundle().pipe(process.stdout)