It looked for the tag written as `css` immediately followed by a
backtick. The plugin is a Rollup transform, so the module has already
been through TypeScript by the time it arrives, and the TS printer puts
a space there: `css `. The guard therefore returned null for every
stylesheet in the project, and minification never ran once — around
23 KB of explanatory comments went to every user in every release.
Matching the tag as a word with optional whitespace turns it on:
chunk, raw 1 079 508 -> 1 021 115 B (-58 393)
initial view 300 111 -> 287 284 B gzip (-12 816)
room to the budget 955 -> 13 782 B
The ceiling moves down with the fact, as the tool asks when a graph
shrinks past the band.
The risk is not the two lines; it is that 23 KB of CSS is minified for
the first time. Two witnesses cover it: a browser smoke that puts the
original and the minified text into separate stylesheets and compares
the serialised rules — 1 049 of them, identical up to the whitespace
policy the minifier declares — and a test that takes real comment text
out of src/styles and requires it to be absent from dist, so a plugin
that silently stops working cannot pass again.
Issue: #526
User-Visible: yes
Codex