Urara-Blog/node_modules/.pnpm-store/v3/files/74/3e6a3de06e58cff311708e3646e79fa82748c8b4fa791c20e23d6f02b3bdbf91daa7da2a7bb9d7785d391b3e52301ba45d7c89b8dc1244ba73458d4992d905
2022-08-14 01:14:53 +08:00

248 lines
5.3 KiB
Text

'use strict';
const valueParser = require('postcss-value-parser');
const directionKeywords = new Set(['top', 'right', 'bottom', 'left', 'center']);
const center = '50%';
const horizontal = new Map([
['right', '100%'],
['left', '0'],
]);
const verticalValue = new Map([
['bottom', '100%'],
['top', '0'],
]);
const mathFunctions = new Set(['calc', 'min', 'max', 'clamp']);
const variableFunctions = new Set(['var', 'env', 'constant']);
/**
* @param {valueParser.Node} node
* @return {boolean}
*/
function isCommaNode(node) {
return node.type === 'div' && node.value === ',';
}
/**
* @param {valueParser.Node} node
* @return {boolean}
*/
function isVariableFunctionNode(node) {
if (node.type !== 'function') {
return false;
}
return variableFunctions.has(node.value.toLowerCase());
}
/**
* @param {valueParser.Node} node
* @return {boolean}
*/
function isMathFunctionNode(node) {
if (node.type !== 'function') {
return false;
}
return mathFunctions.has(node.value.toLowerCase());
}
/**
* @param {valueParser.Node} node
* @return {boolean}
*/
function isNumberNode(node) {
if (node.type !== 'word') {
return false;
}
const value = parseFloat(node.value);
return !isNaN(value);
}
/**
* @param {valueParser.Node} node
* @return {boolean}
*/
function isDimensionNode(node) {
if (node.type !== 'word') {
return false;
}
const parsed = valueParser.unit(node.value);
if (!parsed) {
return false;
}
return parsed.unit !== '';
}
/**
* @param {string} value
* @return {string}
*/
function transform(value) {
const parsed = valueParser(value);
/** @type {({start: number, end: number} | {start: null, end: null})[]} */
const ranges = [];
let rangeIndex = 0;
let shouldContinue = true;
parsed.nodes.forEach((node, index) => {
// After comma (`,`) follows next background
if (isCommaNode(node)) {
rangeIndex += 1;
shouldContinue = true;
return;
}
if (!shouldContinue) {
return;
}
// After separator (`/`) follows `background-size` values
// Avoid them
if (node.type === 'div' && node.value === '/') {
shouldContinue = false;
return;
}
if (!ranges[rangeIndex]) {
ranges[rangeIndex] = {
start: null,
end: null,
};
}
// Do not try to be processed `var and `env` function inside background
if (isVariableFunctionNode(node)) {
shouldContinue = false;
ranges[rangeIndex].start = null;
ranges[rangeIndex].end = null;
return;
}
const isPositionKeyword =
(node.type === 'word' &&
directionKeywords.has(node.value.toLowerCase())) ||
isDimensionNode(node) ||
isNumberNode(node) ||
isMathFunctionNode(node);
if (ranges[rangeIndex].start === null && isPositionKeyword) {
ranges[rangeIndex].start = index;
ranges[rangeIndex].end = index;
return;
}
if (ranges[rangeIndex].start !== null) {
if (node.type === 'space') {
return;
} else if (isPositionKeyword) {
ranges[rangeIndex].end = index;
return;
}
return;
}
});
ranges.forEach((range) => {
if (range.start === null) {
return;
}
const nodes = parsed.nodes.slice(range.start, range.end + 1);
if (nodes.length > 3) {
return;
}
const firstNode = nodes[0].value.toLowerCase();
const secondNode =
nodes[2] && nodes[2].value ? nodes[2].value.toLowerCase() : null;
if (nodes.length === 1 || secondNode === 'center') {
if (secondNode) {
nodes[2].value = nodes[1].value = '';
}
const map = new Map([...horizontal, ['center', center]]);
if (map.has(firstNode)) {
nodes[0].value = /** @type {string}*/ (map.get(firstNode));
}
return;
}
if (secondNode !== null) {
if (firstNode === 'center' && directionKeywords.has(secondNode)) {
nodes[0].value = nodes[1].value = '';
if (horizontal.has(secondNode)) {
nodes[2].value = /** @type {string} */ (horizontal.get(secondNode));
}
return;
}
if (horizontal.has(firstNode) && verticalValue.has(secondNode)) {
nodes[0].value = /** @type {string} */ (horizontal.get(firstNode));
nodes[2].value = /** @type {string} */ (verticalValue.get(secondNode));
return;
} else if (verticalValue.has(firstNode) && horizontal.has(secondNode)) {
nodes[0].value = /** @type {string} */ (horizontal.get(secondNode));
nodes[2].value = /** @type {string} */ (verticalValue.get(firstNode));
return;
}
}
});
return parsed.toString();
}
/**
* @type {import('postcss').PluginCreator<void>}
* @return {import('postcss').Plugin}
*/
function pluginCreator() {
return {
postcssPlugin: 'postcss-normalize-positions',
OnceExit(css) {
const cache = new Map();
css.walkDecls(
/^(background(-position)?|(-\w+-)?perspective-origin)$/i,
(decl) => {
const value = decl.value;
if (!value) {
return;
}
if (cache.has(value)) {
decl.value = cache.get(value);
return;
}
const result = transform(value);
decl.value = result;
cache.set(value, result);
}
);
},
};
}
pluginCreator.postcss = true;
module.exports = pluginCreator;