stylus/js/sections-util.js
2020-11-09 21:08:47 +03:00

91 lines
3.0 KiB
JavaScript

/* exported styleSectionsEqual styleCodeEmpty styleSectionGlobal calcStyleDigest styleJSONseemsValid */
'use strict';
function styleCodeEmpty(code) {
if (!code) {
return true;
}
const rx = /\s+|\/\*[\s\S]*?\*\/|@namespace[^;]+;|@charset[^;]+;/giy;
while (rx.exec(code)) {
if (rx.lastIndex === code.length) {
return true;
}
}
return false;
}
/** Checks if section is global i.e. has no targets at all */
function styleSectionGlobal(section) {
return (!section.regexps || !section.regexps.length) &&
(!section.urlPrefixes || !section.urlPrefixes.length) &&
(!section.urls || !section.urls.length) &&
(!section.domains || !section.domains.length);
}
/**
* The sections are checked in successive order because it matters when many sections
* match the same URL and they have rules with the same CSS specificity
* @param {Object} a - first style object
* @param {Object} b - second style object
* @returns {?boolean}
*/
function styleSectionsEqual({sections: a}, {sections: b}) {
const targets = ['urls', 'urlPrefixes', 'domains', 'regexps'];
return a && b && a.length === b.length && a.every(sameSection);
function sameSection(secA, i) {
return equalOrEmpty(secA.code, b[i].code, 'string', (a, b) => a === b) &&
targets.every(target => equalOrEmpty(secA[target], b[i][target], 'array', arrayMirrors));
}
function equalOrEmpty(a, b, type, comparator) {
const typeA = type === 'array' ? Array.isArray(a) : typeof a === type;
const typeB = type === 'array' ? Array.isArray(b) : typeof b === type;
return typeA && typeB && comparator(a, b) ||
(a == null || typeA && !a.length) &&
(b == null || typeB && !b.length);
}
function arrayMirrors(a, b) {
return a.length === b.length &&
a.every(el => b.includes(el)) &&
b.every(el => a.includes(el));
}
}
function normalizeStyleSections({sections}) {
// retain known properties in an arbitrarily predefined order
return (sections || []).map(section => /** @namespace StyleSection */({
code: section.code || '',
urls: section.urls || [],
urlPrefixes: section.urlPrefixes || [],
domains: section.domains || [],
regexps: section.regexps || [],
}));
}
function calcStyleDigest(style) {
const jsonString = style.usercssData ?
style.sourceCode : JSON.stringify(normalizeStyleSections(style));
const text = new TextEncoder('utf-8').encode(jsonString);
return crypto.subtle.digest('SHA-1', text).then(hex);
function hex(buffer) {
const parts = [];
const PAD8 = '00000000';
const view = new DataView(buffer);
for (let i = 0; i < view.byteLength; i += 4) {
parts.push((PAD8 + view.getUint32(i).toString(16)).slice(-8));
}
return parts.join('');
}
}
function styleJSONseemsValid(json) {
return json
&& json.name
&& json.name.trim()
&& Array.isArray(json.sections)
&& json.sections
&& json.sections.length
&& typeof json.sections.every === 'function'
&& typeof json.sections[0].code === 'string';
}