Merge with existing manifest.json?

[ivancuric]

Any ideas on how to merge with an existing manifest.json generated by other processes?

[mastilver]

Would doing:

{
  cache: JSON.parse(fs.readFileSync(...))
}

be enough or should we add an options to handle that?

cc @gmac

[gmac]

This is actually a fairly well-defined use case in multi-compiler architectures where we want a single manifest that documents output from all compilers. This can be achieved by passing a shared cache object to all plugin instances, such as:

var manifest = {};
var compiler1 = { ..., plugins: [ new WebpackManifestPlugin({ cache: manifest }) ] };
var compiler2 = { ..., plugins: [ new WebpackManifestPlugin({ cache: manifest }) ] };

Note that this pattern requires a single object instance to be shared; the system won't work as expected if you pass unique object clones to each plugin instance.

[mastilver]

@gmac Yeah I got that, but do you think the code I posted above is alright to handle merging with an existing manifest.json in the case of a single compiler?

[gmac]

@mastilver yep, looks right to me!

[mastilver]

module.exports = {
    // ...
    plugins: [
      new ManifestPlugin({
        cache: JSON.parse(fs.readFileSync(path.join(__dirname, 'manifest.json'))
      })
    ]
};