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dmitrivMS merged 2 commits into from
Jul 20, 2026
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Merged

Add @layer syntax highlighting #52

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e88bcb9
Add CSS @layer syntax highlighting
Poliklot May 22, 2026
978d804
Refine @import layer whitespace scoping
Poliklot Jul 3, 2026
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116 changes: 116 additions & 0 deletions grammars/css.cson
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -140,6 +140,12 @@
{
'include': '#url'
}
{
'match': '\\s+'
}
{
'include': '#layer-import'
}
{
'include': '#media-query-list'
}
Expand Down Expand Up @@ -481,6 +487,53 @@
}
]
}
{
# @layer
'begin': '(?i)(?=@layer(?:[\\s{;]|/\\*|$))'
'end': '(?<=})(?!\\G)|;'
'endCaptures':
'0':
'name': 'punctuation.terminator.rule.css'
'patterns': [
{
'begin': '(?i)\\G(@)layer'
'beginCaptures':
'0':
'name': 'keyword.control.at-rule.layer.css'
'1':
'name': 'punctuation.definition.keyword.css'
'end': '(?=\\s*[{;])'
'name': 'meta.at-rule.layer.header.css'
'patterns': [
{
'include': '#layer-name-list'
}
{
'include': '#comment-block'
}
{
'include': '#escapes'
}
]
}
{
'begin': '{'
'beginCaptures':
'0':
'name': 'punctuation.section.layer.begin.bracket.curly.css'
'end': '}'
'endCaptures':
'0':
'name': 'punctuation.section.layer.end.bracket.curly.css'
'name': 'meta.at-rule.layer.body.css'
'patterns': [
{
'include': '$self'
}
]
}
]
}
{
# @viewport
'begin': '(?i)((@)(-(ms|o)-)?viewport)(?=[\\s\'"{;]|/\\*|$)'
Expand Down Expand Up @@ -640,6 +693,69 @@
]
}
]
'layer-import':
'patterns': [
{
'begin': '(?i)(?<![\\w-])(layer)(\\()'
'beginCaptures':
'1':
'name': 'support.function.layer.css'
'2':
'name': 'punctuation.section.function.begin.bracket.round.css'
'end': '\\)'
'endCaptures':
'0':
'name': 'punctuation.section.function.end.bracket.round.css'
'name': 'meta.function.layer.css'
'patterns': [
{
'include': '#layer-name-list'
}
{
'include': '#comment-block'
}
{
'include': '#escapes'
}
]
}
{
'captures':
'1':
'name': 'keyword.other.layer.css'
'match': '(?i)(?<![\\w-])(layer)(?![\\w-])'
}
]
'layer-name-list':
'patterns': [
{
'include': '#comment-block'
}
{
'match': ','
'name': 'punctuation.separator.list.comma.css'
}
{
'match': '\\.'
'name': 'punctuation.accessor.layer.css'
}
{
'captures':
'0':
'patterns': [
{
'include': '#escapes'
}
]
'match': '''(?x)
(?:[-a-zA-Z_] | [^\\x00-\\x7F]) # First letter
(?:[-a-zA-Z0-9_] | [^\\x00-\\x7F] # Remainder of identifier
|\\\\(?:[0-9a-fA-F]{1,6}|.)
)*
'''
'name': 'variable.parameter.layer-name.css'
}
]
'color-keywords':
'patterns': [
{
Expand Down
63 changes: 63 additions & 0 deletions spec/css-spec.mjs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1567,6 +1567,69 @@ describe('CSS grammar', function () {
});
});

describe('@layer', function () {
it('tokenises layer statement lists', function () {
var tokens;
tokens = testGrammar.tokenizeLine('@layer reset, framework.theme;').tokens;
assert.deepStrictEqual(tokens[0], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css', 'punctuation.definition.keyword.css'], value: '@' });
assert.deepStrictEqual(tokens[1], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css'], value: 'layer' });
assert.deepStrictEqual(tokens[3], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'variable.parameter.layer-name.css'], value: 'reset' });
assert.deepStrictEqual(tokens[4], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'punctuation.separator.list.comma.css'], value: ',' });
assert.deepStrictEqual(tokens[6], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'variable.parameter.layer-name.css'], value: 'framework' });
assert.deepStrictEqual(tokens[7], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'punctuation.accessor.layer.css'], value: '.' });
assert.deepStrictEqual(tokens[8], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'variable.parameter.layer-name.css'], value: 'theme' });
assert.deepStrictEqual(tokens[9], { scopes: ['source.css', 'punctuation.terminator.rule.css'], value: ';' });
});

it('embeds rulesets and other at-rules', function () {
var lines;
lines = testGrammar.tokenizeLines("@layer framework {\n @media (width >= 20em) {\n .button { color: red; }\n }\n}");
assert.deepStrictEqual(lines[0][0], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css', 'punctuation.definition.keyword.css'], value: '@' });
assert.deepStrictEqual(lines[0][1], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css'], value: 'layer' });
assert.deepStrictEqual(lines[0][3], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'variable.parameter.layer-name.css'], value: 'framework' });
assert.deepStrictEqual(lines[0][5], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'punctuation.section.layer.begin.bracket.curly.css'], value: '{' });
assert.deepStrictEqual(lines[1][1], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.media.header.css', 'keyword.control.at-rule.media.css', 'punctuation.definition.keyword.css'], value: '@' });
assert.deepStrictEqual(lines[1][2], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.media.header.css', 'keyword.control.at-rule.media.css'], value: 'media' });
assert.deepStrictEqual(lines[2][1], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.media.body.css', 'meta.selector.css', 'entity.other.attribute-name.class.css', 'punctuation.definition.entity.css'], value: '.' });
assert.deepStrictEqual(lines[2][2], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.media.body.css', 'meta.selector.css', 'entity.other.attribute-name.class.css'], value: 'button' });
assert.deepStrictEqual(lines[4][0], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'punctuation.section.layer.end.bracket.curly.css'], value: '}' });
});

it('tokenises anonymous and nested layers', function () {
var tokens;
tokens = testGrammar.tokenizeLine('@layer { .foo {} }').tokens;
assert.deepStrictEqual(tokens[0], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css', 'punctuation.definition.keyword.css'], value: '@' });
assert.deepStrictEqual(tokens[1], { scopes: ['source.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css'], value: 'layer' });
assert.deepStrictEqual(tokens[3], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'punctuation.section.layer.begin.bracket.curly.css'], value: '{' });
assert.deepStrictEqual(tokens[5], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.selector.css', 'entity.other.attribute-name.class.css', 'punctuation.definition.entity.css'], value: '.' });
assert.deepStrictEqual(tokens[11], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'punctuation.section.layer.end.bracket.curly.css'], value: '}' });

tokens = testGrammar.tokenizeLine('@layer foo { @layer bar { .foo {} } }').tokens;
assert.deepStrictEqual(tokens[7], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css', 'punctuation.definition.keyword.css'], value: '@' });
assert.deepStrictEqual(tokens[8], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.layer.header.css', 'keyword.control.at-rule.layer.css'], value: 'layer' });
assert.deepStrictEqual(tokens[10], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.layer.header.css', 'variable.parameter.layer-name.css'], value: 'bar' });
assert.deepStrictEqual(tokens[12], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.layer.body.css', 'punctuation.section.layer.begin.bracket.curly.css'], value: '{' });
assert.deepStrictEqual(tokens[20], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'meta.at-rule.layer.body.css', 'punctuation.section.layer.end.bracket.curly.css'], value: '}' });
assert.deepStrictEqual(tokens[22], { scopes: ['source.css', 'meta.at-rule.layer.body.css', 'punctuation.section.layer.end.bracket.curly.css'], value: '}' });
});
});

describe('@import layer', function () {
it('tokenises imported layer names', function () {
var tokens;
tokens = testGrammar.tokenizeLine('@import url("theme.css") layer(framework.theme);').tokens;
assert.deepStrictEqual(tokens[10], { scopes: ['source.css', 'meta.at-rule.import.css', 'meta.function.layer.css', 'support.function.layer.css'], value: 'layer' });
assert.deepStrictEqual(tokens[11], { scopes: ['source.css', 'meta.at-rule.import.css', 'meta.function.layer.css', 'punctuation.section.function.begin.bracket.round.css'], value: '(' });
assert.deepStrictEqual(tokens[12], { scopes: ['source.css', 'meta.at-rule.import.css', 'meta.function.layer.css', 'variable.parameter.layer-name.css'], value: 'framework' });
assert.deepStrictEqual(tokens[13], { scopes: ['source.css', 'meta.at-rule.import.css', 'meta.function.layer.css', 'punctuation.accessor.layer.css'], value: '.' });
assert.deepStrictEqual(tokens[14], { scopes: ['source.css', 'meta.at-rule.import.css', 'meta.function.layer.css', 'variable.parameter.layer-name.css'], value: 'theme' });
assert.deepStrictEqual(tokens[15], { scopes: ['source.css', 'meta.at-rule.import.css', 'meta.function.layer.css', 'punctuation.section.function.end.bracket.round.css'], value: ')' });

tokens = testGrammar.tokenizeLine('@import "theme.css" layer;').tokens;
assert.deepStrictEqual(tokens[7], { scopes: ['source.css', 'meta.at-rule.import.css', 'keyword.other.layer.css'], value: 'layer' });
});
});

describe('@namespace', function () {
it('tokenises @namespace statements correctly', function () {
var tokens;
Expand Down
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