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[CSS consolidation] Add extended to store list of extension URLs #1904

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Merged
merged 1 commit into from
Jul 25, 2025
Merged

[CSS consolidation] Add extended to store list of extension URLs #1904

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12 changes: 12 additions & 0 deletions schemas/postprocessing/css.json
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,13 @@
"type": "string"
},
"minItems": 1
},

"extended": {
"type": "array",
"items": {
"$ref": "../common.json#/$defs/url"
}
}
},

Expand All @@ -25,6 +32,7 @@
"properties": {
"name": { "type": "string", "pattern": "^@" },
"href": { "$ref": "../common.json#/$defs/url" },
"extended": { "$ref": "#/$defs/extended" },
"syntax": { "$ref": "../common.json#/$defs/cssValue" },
"prose": { "type": "string" },
"descriptors": {
Expand Down Expand Up @@ -54,6 +62,7 @@
"name": { "type": "string", "pattern": "^.*()$" },
"for": { "$ref": "#/$defs/scopes" },
"href": { "$ref": "../common.json#/$defs/url" },
"extended": { "$ref": "#/$defs/extended" },
"prose": { "type": "string" },
"syntax": { "$ref": "../common.json#/$defs/cssValue" }
}
Expand All @@ -68,6 +77,7 @@
"properties": {
"name": { "$ref": "../common.json#/$defs/cssPropertyName" },
"href": { "$ref": "../common.json#/$defs/url" },
"extended": { "$ref": "#/$defs/extended" },
"syntax": { "$ref": "../common.json#/$defs/cssValue" },
"legacyAliasOf": { "$ref": "../common.json#/$defs/cssPropertyName" },
"styleDeclaration": {
Expand All @@ -87,6 +97,7 @@
"properties": {
"name": { "$ref": "../common.json#/$defs/cssPropertyName" },
"href": { "$ref": "../common.json#/$defs/url" },
"extended": { "$ref": "#/$defs/extended" },
"prose": { "type": "string" },
"syntax": { "$ref": "../common.json#/$defs/cssValue" }
}
Expand All @@ -102,6 +113,7 @@
"name": { "type": "string", "pattern": "^[a-zA-Z0-9-\\+\\(\\)\\[\\]\\{\\}]+$" },
"for": { "$ref": "#/$defs/scopes" },
"href": { "$ref": "../common.json#/$defs/url" },
"extended": { "$ref": "#/$defs/extended" },
"prose": { "type": "string" },
"syntax": { "$ref": "../common.json#/$defs/cssValue" }
}
Expand Down
37 changes: 30 additions & 7 deletions src/postprocessing/cssmerge.js
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Original file line number Diff line number Diff line change
Expand Up @@ -111,8 +111,9 @@ export default {

// The job is "almost" done but we now need to de-duplicate entries.
// Duplicated entries exist when:
// - A property is defined in one spec and extended in other specs. We'll
// consolidate the entries (and syntaxes) to get back to a single entry.
// - A property, function or type is defined in one spec and extended in
// other specs. We'll consolidate the entries (and syntaxes) to get back to
// a single entry.
// - An at-rule is defined in one spec. Additional descriptors are defined
// in other specs. We'll consolidate the entries similarly.
// - A descriptor is defined in one level of a spec series, and re-defined
Expand Down Expand Up @@ -179,13 +180,22 @@ export default {
// Identify the base definition for each feature, using the definition
// (that has some known syntax) in the most recent level. Move that base
// definition to the beginning of the array and get rid of other base
// definitions.
// (Note: the code chooses one definition if duplicates of base
// definitions in unrelated specs still exist)
// definitions. Notes:
// - For properties, an extension is an entry with a `newValues` key.
// - For functions and types, an extension is an entry without an `href`
// key (the spec that extends the base type does not contain any `<dfn>`)
// - The code chooses one definition if duplicates of base definitions in
// unrelated specs still exist.
for (const [name, dfns] of Object.entries(featureDfns)) {
let actualDfns = dfns.filter(dfn => dfn.syntax);
let actualDfns = dfns.filter(dfn => dfn.href && dfn.syntax);
if (actualDfns.length === 0) {
actualDfns = dfns.filter(dfn => !dfn.newValues);
actualDfns = dfns.filter(dfn => dfn.href && !dfn.newValues);
}
if (actualDfns.length === 0) {
// No base definition, not a real type, let's discard it
// (problem should be captured through tests on individual extracts)
delete featureDfns[name];
continue;
}
const best = actualDfns.reduce((dfn1, dfn2) => {
if (dfn1.spec.series.shortname !== dfn2.spec.series.shortname) {
Expand All @@ -199,6 +209,7 @@ export default {
return dfn1;
}
});
best.extended = [];
featureDfns[name] = [best].concat(
dfns.filter(dfn => !actualDfns.includes(dfn))
);
Expand Down Expand Up @@ -239,6 +250,18 @@ export default {
continue;
}
baseDfn.syntax += ' | ' + dfn.newValues;
baseDfn.extended.push(dfn.href);
}
else if (dfn.syntax) {
// Extensions of functions and types are *re-definitions* in
// practice, new syntax overrides the base one. There should be
// only one such extension in unrelated specs, the code assumes
// that some sort of curation already took place, and picks up
// a winner randomly.
// Note: we don't have any `href` info for functions/types
// extensions, so we'll just use the URL of the crawled spec.
baseDfn.syntax = dfn.syntax;
baseDfn.extended = [dfn.spec.crawled ?? dfn.spec.url];
}
if (baseDfn.descriptors && dfn.descriptors?.length > 0) {
baseDfn.descriptors.push(...dfn.descriptors.filter(desc =>
Expand Down
88 changes: 78 additions & 10 deletions test/merge-css.js
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Original file line number Diff line number Diff line change
Expand Up @@ -54,7 +54,7 @@ const descriptorBase = {
type: 'discrete'
};

const descriptorExtended = Object.assign({}, descriptorBase, {
const descriptorExtension = Object.assign({}, descriptorBase, {
href: 'https://drafts.csswg.org/css-stuff-2/#descdef-descriptor',
value: 'extended'
});
Expand All @@ -77,6 +77,7 @@ const property1 = {

const propertyLegacy = {
name: 'good-old-overlay',
href: 'https://compat.spec.whatwg.org/#good-old-overlay',
legacyAliasOf: 'overlay'
};

Expand All @@ -93,6 +94,12 @@ const type1 = {
value: 'repeat | space | round | no-repeat'
};

const type1Extension = {
name: '<repetition>',
type: 'type',
value: 'bis repetita'
};

const functionVar = {
name: 'var()',
href: 'https://drafts.csswg.org/css-variables-2/#funcdef-var',
Expand All @@ -113,14 +120,17 @@ const functionEnv = {
* the outputs to the inputs directly. This conversion function takes
* some object or value and converts it to ease comparisons.
*/
function conv(entry) {
function conv(entry, parentKey) {
const res = {};
if (typeof entry !== 'object') {
return entry;
}
if (entry.href && !entry.extended && parentKey !== 'descriptors') {
entry.extended = [];
}
for (const [key, value] of Object.entries(entry)) {
if (Array.isArray(value)) {
res[key] = value.map(conv);
res[key] = value.map(v => conv(v, key));
}
else if (key === 'value') {
res.syntax = value;
Expand Down Expand Up @@ -309,7 +319,8 @@ describe('CSS extracts consolidation', function () {
properties: [
Object.assign({}, property1, {
value: null,
newValues: 'train'
newValues: 'train',
href: 'https://drafts.csswg.org/css-otherstuff-2/#tchou-tchou'
})
]
})
Expand All @@ -318,7 +329,8 @@ describe('CSS extracts consolidation', function () {
const result = await cssmerge.run({ results });
assert.deepEqual(result.properties, [
Object.assign({}, conv(property1), {
syntax: 'none | auto | train'
syntax: 'none | auto | train',
extended: ['https://drafts.csswg.org/css-otherstuff-2/#tchou-tchou']
})
]);
});
Expand All @@ -344,7 +356,8 @@ describe('CSS extracts consolidation', function () {
properties: [
Object.assign({}, property1, {
value: null,
newValues: 'train'
newValues: 'train',
href: 'https://drafts.csswg.org/css-otherstuff-1/#tchou-tchou'
})
]
})
Expand All @@ -357,7 +370,8 @@ describe('CSS extracts consolidation', function () {
properties: [
Object.assign({}, property1, {
value: null,
newValues: 'train'
newValues: 'train',
href: 'https://drafts.csswg.org/css-otherstuff-2/#tchou-tchou'
})
]
})
Expand All @@ -366,7 +380,8 @@ describe('CSS extracts consolidation', function () {
const result = await cssmerge.run({ results });
assert.deepEqual(result.properties, [
Object.assign({}, conv(property1), {
syntax: 'none | auto | train'
syntax: 'none | auto | train',
extended: ['https://drafts.csswg.org/css-otherstuff-2/#tchou-tchou']
})
]);
});
Expand Down Expand Up @@ -432,7 +447,7 @@ describe('CSS extracts consolidation', function () {
css: Object.assign({}, emptyExtract, {
atrules: [
Object.assign({}, atrule2, {
descriptors: [descriptorExtended]
descriptors: [descriptorExtension]
})
]
})
Expand All @@ -442,7 +457,7 @@ describe('CSS extracts consolidation', function () {
assert.deepEqual(result.atrules, [
conv(Object.assign({}, atrule2, {
syntax: '@media foo',
descriptors: [descriptorExtended]
descriptors: [descriptorExtension]
}))
]);
});
Expand Down Expand Up @@ -630,4 +645,57 @@ describe('CSS extracts consolidation', function () {
]
})));
});

it('merges extended types', async () => {
const results = structuredClone([
{
shortname: 'css-stuff-1',
series: { shortname: 'css-stuff' },
seriesVersion: '1',
crawled: 'https://drafts.csswg.org/css-stuff-1/',
css: Object.assign({}, emptyExtract, {
values: [
Object.assign({}, type1)
]
})
},
{
shortname: 'css-otherstuff-1',
series: { shortname: 'css-otherstuff' },
seriesVersion: '1',
crawled: 'https://drafts.csswg.org/css-otherstuff-1/',
css: Object.assign({}, emptyExtract, {
values: [
Object.assign({}, type1Extension)
]
})
},
]);
const result = await cssmerge.run({ results });
assert.deepEqual(result, conv(Object.assign({}, emptyMerged, {
types: [
Object.assign({}, conv(type1), {
syntax: type1Extension.value,
extended: ['https://drafts.csswg.org/css-otherstuff-1/']
})
]
})));
});

it('discards type extensions without a base definition', async () => {
const results = structuredClone([
{
shortname: 'css-stuff-1',
series: { shortname: 'css-stuff' },
seriesVersion: '1',
css: Object.assign({}, emptyExtract, {
values: [
Object.assign({}, type1Extension)
]
})
}
]);
const result = await cssmerge.run({ results });
assert.deepEqual(result, conv(emptyMerged));
});
});