svelte-check error with nth-last-child selector

[theodorejb]

Describe the bug

In my Svelte component I have a style tag with the following rule:

tr:nth-last-child(1 of :not(.d-sm-none)) {
    border-bottom: 0;
}

The CSS works fine, but when I run svelte-check, it outputs the following errors:

Error: at-rule or selector expected (css)
        border-bottom: 0;
    }
</style>


c:\Users\Theodore\my-project\src\lib\MyComponent.svelte:75:44
Error: { expected (css)
<style>
    tr:nth-last-child(1 of :not(.d-sm-none)) {
        border-bottom: 0;


c:\Users\Theodore\my-project\src\lib\MyComponent.svelte:75:25
Error: ) expected (css)
<style>
    tr:nth-last-child(1 of :not(.d-sm-none)) {
        border-bottom: 0;


====================================
svelte-check found 3 errors and 0 warnings in 1 file

Reproduction

See above description.

Expected behaviour

Svelte-check should not output a syntax error for this valid CSS.

System Info

• OS: Windows
• IDE: VSCode

Which package is the issue about?

svelte-check

Additional Information, eg. Screenshots

Strangely, there is no error with the following CSS:

tr:nth-last-child(odd of :not(.d-sm-none)) {
    border-bottom: 0;
}

So svelte-check seems to specifically fail to parse to the CSS when the first argument to nth-last-child is something other than odd or even.

[jasonlyu123]

This has only been implemented in Chrome and Firefox very recently. See the issue on the VSCode repo
microsoft/vscode#181560. We use the same underlying library that is maintained by the VSCode team.

[dummdidumm]

Should work now since we bumped the css language service dep