handle line-breaks around custom fragments gracefully

[alexlamsl]

@gzzhanghao this is what I have in mind with regards to #716 and #719. Does this address all your cases?

[gzzhanghao]

It works like a charm! Can't wait to merge this 😃

[gzzhanghao]

The issue in #716 still exists in this branch. I think we should restore all substitutions in the escapeFragments method.

[alexlamsl]

@gzzhanghao thanks for the review - I'll go fix it up now... 😉

[alexlamsl]

Just tried your example in #716 and it seems to work:

> minify(`<script>
... function a() {
.....   b()
.....   <?php if (false): ?>
.....     c()
.....   <?php endif; ?>
..... }
... </script>`, {minifyJS:true})
'<script>function a(){b(),\n<?php if (false): ?>\n,c(),\n<?php endif; ?>\n}</script>'

What other options have you specified which produce the incorrect results as you described?

[gzzhanghao]

@alexlamsl It becomes <script>function a(){b(),\n\n}</script> after running in php runtime. The trailing comma leads to a syntax error :(

Custom fragments are not valid javascript stuff, I think we can't simply treat it as a identifier in javascript.

[alexlamsl]

@gzzhanghao now I see what you mean.

Yeah, this one is inherently tricky, and the same issue would arise with minifyCSS as well. I guess I'll merge this for now and think about #716 some more, as they are separate issues...