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Diffstat (limited to 'node_modules/postcss-normalize-unicode/src/index.js')
| -rw-r--r-- | node_modules/postcss-normalize-unicode/src/index.js | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/node_modules/postcss-normalize-unicode/src/index.js b/node_modules/postcss-normalize-unicode/src/index.js new file mode 100644 index 00000000..d8a562b8 --- /dev/null +++ b/node_modules/postcss-normalize-unicode/src/index.js @@ -0,0 +1,132 @@ +'use strict'; +const browserslist = require('browserslist'); +const valueParser = require('postcss-value-parser'); + +const regexLowerCaseUPrefix = /^u(?=\+)/; + +/** + * @param {string} range + * @return {string} + */ +function unicode(range) { + const values = range.slice(2).split('-'); + + if (values.length < 2) { + return range; + } + + const left = values[0].split(''); + const right = values[1].split(''); + + if (left.length !== right.length) { + return range; + } + + const merged = mergeRangeBounds(left, right); + + if (merged) { + return merged; + } + + return range; +} +/** + * @param {string[]} left + * @param {string[]} right + * @return {false|string} + */ +function mergeRangeBounds(left, right) { + let questionCounter = 0; + let group = 'u+'; + for (const [index, value] of left.entries()) { + if (value === right[index] && questionCounter === 0) { + group = group + value; + } else if (value === '0' && right[index] === 'f') { + questionCounter++; + group = group + '?'; + } else { + return false; + } + } + // The maximum number of wildcard characters (?) for ranges is 5. + if (questionCounter < 6) { + return group; + } else { + return false; + } +} + +/** + * IE and Edge before 16 version ignore the unicode-range if the 'U' is lowercase + * + * https://caniuse.com/#search=unicode-range + * + * @param {string} browser + * @return {boolean} + */ +function hasLowerCaseUPrefixBug(browser) { + return browserslist('ie <=11, edge <= 15').includes(browser); +} + +/** + * @param {string} value + * @return {string} + */ +function transform(value, isLegacy = false) { + return valueParser(value) + .walk((child) => { + if (child.type === 'unicode-range') { + const transformed = unicode(child.value.toLowerCase()); + + child.value = isLegacy + ? transformed.replace(regexLowerCaseUPrefix, 'U') + : transformed; + } + + return false; + }) + .toString(); +} + +/** + * @type {import('postcss').PluginCreator<void>} + * @return {import('postcss').Plugin} + */ +function pluginCreator() { + return { + postcssPlugin: 'postcss-normalize-unicode', + /** @param {import('postcss').Result & {opts: browserslist.Options}} result*/ + prepare(result) { + const cache = new Map(); + const resultOpts = result.opts || {}; + const browsers = browserslist(null, { + stats: resultOpts.stats, + path: __dirname, + env: resultOpts.env, + }); + const isLegacy = browsers.some(hasLowerCaseUPrefixBug); + + return { + OnceExit(css) { + css.walkDecls(/^unicode-range$/i, (decl) => { + const value = decl.value; + + if (cache.has(value)) { + decl.value = cache.get(value); + + return; + } + + const newValue = transform(value, isLegacy); + + decl.value = newValue; + cache.set(value, newValue); + }); + }, + }; + }, + }; +} + +pluginCreator.postcss = true; +module.exports = pluginCreator; |
