script type=text/coffeescript tag does not support unicode (utf-8) properly

[Masterxilo]

Running this html file, saved with utf-8 encoding (no BOM) in Chrome:

<meta charset=utf-8>
<script src=/lib/coffee-script.js></script>
<script>
alert('js:おねがいします')
</script>
<script type=text/coffeescript>
alert('cs:おねがいします')
</script>

generates

coffee-script.js:6459 Uncaught InvalidCharacterError: Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.

The error is generated on the lines saying

      case typeof btoa !== 'function':
        return btoa(src);

in coffee-script.js

The javascript tag has no problems with this string.

[Masterxilo]

I guess this lists solutions on how to make btoa deal with utf-8:

https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding#Solution_.232_.E2.80.93_rewriting_atob()_and_btoa()_using_TypedArrays_and_UTF-8

[Masterxilo]

As by these suggestions, replacing

      case typeof btoa !== 'function':
        return btoa(src);

with

case typeof btoa !== 'function':
function b64EncodeUnicode(str) {
    return btoa(encodeURIComponent(str).replace(/%([0-9A-F]{2})/g, function(match, p1) {
        return String.fromCharCode('0x' + p1);
    }));
}
return b64EncodeUnicode(src);

seems to fix the problem for now. More work is needed for determining the implications of this.

(I for one don't even know why this encoding to base64 is needed).

---

Interestingly, the parser does not generally have a problem with utf-8 (that would have been noticed earlier I guess). The following works as expected:

<meta charset=utf-8>
<script src=/lib/coffee-script.js></script>
<script>
alert('js:おねがいします')
</script>
<div id=text>alert('cs:おねがいします')</div>
<script type=text/coffeescript>
eval(document.getElementById('text').innerHTML)
</script>

---

It might be also of interest that the error in the OP appears even when only comments contain non-ascii characters.

[vlad0337187]

I have similar error:
<script type="text/javascript" src="./scripts/coffee-script.js" charset="utf-8"></script>
<script type="text/coffeescript" charset='utf-8'>alert "Рукава и горсти"</script>

throws me into error:
"InvalidCharacterError: String contains an invalid character"

If there will be:
<script type="text/coffeescript" charset='utf-8'>alert "Text in English"</script>
, all will work well.

How to solve this?

[vlad0337187]

I changed this:

to this:

And all worked.

So as for not-optimized and compressed sources, I think the problem is here:
https://github.com/jashkenas/coffeescript/blob/master/lib/coffee-script/coffee-script.js#L31
Simply to change
case typeof btoa !== 'function': return btoa(src);
to
case typeof btoa !== 'function': return src;
will create "hotfix" for this problem.

Thanks to author of the topic for pointing me to the place of problem - strange item "btoa" =)