TypeError: object is not a function

[abilng]

When I added new CompressionPlugin() to plugin array. I am getting a error.

zlib.js:167
      callback(null, buf);
      ^
  TypeError: object is not a function
      at Gzip.onEnd (zlib.js:167:5)
      at Gzip.emit (events.js:117:20)
      at _stream_readable.js:944:16
      at process._tickCallback (node.js:448:13)

node: v0.10.40
npm: 1.4.28

[h4l]

Which version of compression-webpack-plugin are you using and which options are you passing?

[abilng]

version: "0.3.1"

[h4l]

Are you providing your own function with the algorithm option like this?:

module.exports = {
    context: __dirname + "/app",
    entry: "./entry",
    output: {
        path: __dirname + "/dist",
        filename: "bundle.js"
    },
    plugins: [
        new CompressionPlugin({
            algorithm: function(buf, cb) {
                zlib.gzip(buf, {}, cb);
            }
        })
    ]
};

// Results in:
$ webpack
zlib.js:227
    callback(null, buf);
    ^
TypeError: object is not a function
    at Gzip.onEnd (zlib.js:227:5)
    at Gzip.emit (events.js:129:20)
    at _stream_readable.js:908:16
    at process._tickCallback (node.js:355:11)

If so the reason is that 0.3.1 changed the arguments of the algorithm function. See #25. You need to change the signature to function(buf, options, cb)

[smitchell]

I get this error too, on my home machine, but not at work with the same project. It must some version that is different between environments.

"If you do, this is most likely a problem with the angular2-webpack-starter package,"

`zlib.js:227
callback(err, buf);
^

TypeError: callback is not a function
at Gzip.onEnd (zlib.js:227:5)
at emitNone (events.js:85:20)
at Gzip.emit (events.js:179:7)
at endReadableNT (_stream_readable.js:913:12)
at _combinedTickCallback (node.js:383:13)
at process._tickCallback (node.js:407:11)

$ npm -v compression-webpack-plugin
3.8.3
$ node --version
v5.9.0
$ npm -version
3.8.3

[weltraumpirat]

I can confirm a signature change will fix the problem with angular2-webpack-starter package. You need to edit helper.js from this:

function gzipMaxLevel(buffer, callback) {
  return zlib['gzip'](buffer, {level: 9}, callback)
}

to this:

function gzipMaxLevel(buffer, option, callback) {
  return zlib['gzip'](buffer, {level: 9}, callback)
}

[smitchell]

Thanks, I made this change on the machine where "build:prod" was failing and verified it was fixed. What library version caused the need for this change? Is this a breaking change for the machines that were working? I assuming I'll need to bring all our machines to some minimum version of that library.

[weltraumpirat]

As @h4l said:

If so the reason is that 0.3.1 changed the arguments of the algorithm function. See #25. You need to change the signature to function(buf, options, cb)

So 0.3.1 of compression-webpack-plugin changed the API that the angular2-webpack-starter package relies on. The thing is, there's already an open issue that requests the change to be reversed, or at least optional (sic). I probably wouldn't go nuts changing that call on all your machines, if you can postpone it.

[tbrisker]

This error also occurs when using compression-webpack-plugin with node 0.10, which doesn't support the options parameter for gzip.
As a workaround I used the following code:

plugins: [
    new CompressionPlugin({
      algorithm: function(buffer, options, callback){
                   zlib.gzip(buffer, callback);
                 }
    })
]

[michael-ciniawsky]

Will be fixed by either #26 , #27 discussion moved to the respective PR's, feedback highly welcome 😛 . Vote with 👍 / 👎 on the opening post of the PR you prefer