webpack does not generate always unique chunk hashes

Hello, we have noted that sometimes webpack generates the same hash for a chunk, even if the file content has been changed.

Due to this, changes sometimes are not propagated, we experience an error similar to #959 and we’re forced to clear the cache/CDN to make the things work.

We are using the following plugins in the given order:

ExtractTextPlugin
CommonsChunkPlugin
OccurenceOrderPlugin
WebpackAssetsMapPlugin //custom plugin, writes the json stats file to the disk
DeduplePlugin
UglifyJsPlugin

Let me know if you need further details, V.

[scinos]

As @le12484 recommended, I wrote https://www.npmjs.com/package/webpack-plugin-hash-output to precisely fix this problem. It guarantees that you’ll get a [chunkhash] that is always a hash of the content. It solves the two errors in this thread (as summarized by @jhnns).

It even has the option to fail the compilation if, for whatever reason, that postcondition is not met (see option validateOutput).

[jhnns]

As far as I’m understanding it, we have two issues here:

• Some people are complaining about different hashes although the file content is the same @dmitry
• Some people are complaining about the same hashes although the file content has changed @dtothefp

Please note that webpack hashes the final result (chunks and assets), which means that loaders and plugins have been executed before. Thus it is possible that you don’t get the same hashes for the same file content, because you might have installed different versions of loaders and plugins (at least when using npm).

Same goes the other way round. For instance, if you’re using tree-shaking, you might get the same hashes for different file contents if unused code is removed.

It would be very helpful if you could reproduce the error without any plugin. @dtothefp maybe it’s an error with the sri-stats-webpack-plugin? Try to remove as much as the possible so that we can locate the error.