yuicompressor spits out 76 errors when minfying pdf.js

[solsticedhiver]

Well, I tried to minified the pdf.js with yuicompressor (2.4.6) and it fails with reporting like 76 syntax errors.

What else could I use that does not throw erros like this ?

may be you could fix pdf.js so that it please a little bit more yuicompressor ?

[jviereck]

Working with some other compression tools, it turns out that the get foo() and set foo() syntax, that we use for some properties, can't get minified/handled by compressors.

Could this be the case here as well?

[solsticedhiver]

No. It does not seem to like the variable called 'char' or 'byte' and some property named 'private'

the patch remove the "syntax errors" found by yuicompressor
https://gist.github.com/1322918

Note: the first hunk is not needed. i.e removing double vim modeline and 'use strict'
yuicompressor choke on line 13972 and I replaced all instances of private, I don't know if it's needed/correct.
Just double check before applying, please :-)

[jviereck]

@solsticedhiver, thanks for providing this!

I'm wondering why things like 'private', 'char', 'byte' cause problems with yuicompressor. They aren't JS reserved words [1], so it should be all fine to use them.

My feeling is we shouldn't change our code due to some software, that doesn't seem to do what it should do.

@solsticedhiver, have you tried other compressors? Does they have problems as well? Is there a particular reason to use yuicompressor or is it just your flavor compressor?

[1] https://developer.mozilla.org/en/JavaScript/Reference/Reserved_Words

[solsticedhiver]

about [1], private is mentionned as a reserved future keyword though
But even in that case properties.private is stil legal if I understand correctly the last paragraph on "Reserved Word usage"

yuicompressor is the one I have installed here. I was not going to use an online one with a 1MB file, was I ?

"My feeling is we shouldn't change our code due to some software, that doesn't seem to do what it should do."
Yes, I agree.
But that's not a big change either. Just some basic refactoring.

yuicompressor might have thought it's better to flag those words because they might be reserved in some implementations, From what I read http://javascript.about.com/od/reference/g/rbyte.htm I don't know what standards they talk about. but not a recent one I think...

May be one need to open a bug report against yuicompresor ??

[nateklaiber]

For what it's worth, Google Closure Compiler fails when trying to minify, and I received an exception when using YUI compressor. I haven't found anything that will work to minify pdf.js, even though it's recommended.

[sayrer]

ES3 had a longer list of FutureReservedWords

[shenzhuxi]

I go t "Compilation produced 88 syntax errors." from yuicompressor-2.4.7.jar and commit 7859ef0

[jcheng5]

@nateklaiber, Google Closure Compiler actually works if you add the argument --language_in=ECMASCRIPT5 (and results in excellent compression: 737856 (min) / 1248019 (orig) = 0.591)

[ExE-Boss]

The YUI compressor depends on a modified version of Mozilla’s old Rhino JavaScript runtime, which only supports ES3, and char, byte, private, and others are reserved keywords in ES3.