How can I pass Closure Compiler options to r.js in command line?

[disolovyov]

Hi!

I looked at the example build.js file and there's a section for Closure called CompilerOptions, but no examples how to set anything in it (just an empty object).

Tried passing an argument like closure.CompilerOptions.languageIn=ECMASCRIPT5_STRICT to r.js in command line, but that doesn't work. And it probably makes no sense?

Is there a way to pass such an option? Specifically, tell r.js to tell closure to keep 'use strict'; directives.

Thanks.

[jrburke]

Ah, so this looks like a limitation in the conversion of command line args into a JS object. If you use a build file, similar in structure to the example build.js, and then do something like this:

{
    closure: {
      CompilerOptions: {
        languageIn: 'ECMASCRIPT5_STRICT'
    }
}

then I expect that to work. Also note that r.js will try to strip out use strict calls unless useStrict: true is set:
https://github.com/jrburke/r.js/blob/master/build/example.build.js#L118

I'll target this ticket for 1.1 to fix the nested property conversion from the command line. Feel free to also leave a comment if the above build file workaround approach does not work.

[balee]

It is a bit old, but the workaround approach does not work in v2.3.6:
java.lang.ClassCastException: Cannot cast java.lang.String to com.google.javascript.jscomp.CompilerOptions$LanguageMode