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7.2.0 double-escapes class names from postcss-modules-scope (css-loader CSS modules) #362
Description
Since 7.2.0, CSS modules built with css-loader produce selectors that match nothing. postcss-modules-scope passes className() a name css-loader has already escaped, and #349 now escapes it again:
const parser = require("postcss-selector-parser");
parser.className({ value: "a\\+b" }).toString();
// 7.1.8: .a\+b
// 7.2.0: .a\\\+bI can see the release notes call this out, and raws.value is the right way to pass a pre-escaped name, so I'll open a PR on postcss-modules-scope to do that. Until that's released, though, anyone on css-loader with [hash:base64] names (or anything else that escapes) gets broken styles as soon as their install picks up 7.2.0. We hit it in OpenMRS, where all of our distro builds broke.
Would you consider releasing this change as a major, or reverting it in 7.2.x until postcss-modules-scope has the fix out? #360 would do the same to :local(#id) selectors, so it's probably worth holding that one too.
Activity
denniskigen commentedon Nov 9, 2026
PR for postcss-modules-scope: css-modules/postcss-modules-scope#71
revert: escape class values supplied to the constructor (#349)
MoOx commentedon Nov 12, 2026
Thanks for the precise report, and for opening the fix on postcss-modules-scope at the same time.
You were right: 7.2.0 changed what the class constructor does with its input, and that belongs in a major. 7.2.1 reverts it, together with the matching change to the id setter from #326, so values are written as given again, as they were through 7.1.8. 7.2.1 is out as
latest. Both changes are parked in #357 for a future major. I checked 7.2.1 against postcss-modules-scope 3.2.1 itself: the emitted selectors match 7.1.8 again.One correction for anyone who lands here later: plain
[hash:base64]names were not affected, because css-loader strips the hash down to[A-Za-z0-9_]before escaping it. What broke is[local]with a class name that needs escaping,[path],[name]or[folder]with a character such as a space or a parenthesis, and customgetLocalIdentfunctions.#360 and #361 are held, as you suggested. Your postcss-modules-scope PR is still worth landing: passing the unescaped name as
valueand the escaped spelling asraws.valuegives the same output on every 7.x release.