specificity.js
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var Marker = require('../../tokenizer/marker');
var Selector = {
ADJACENT_SIBLING: '+',
DESCENDANT: '>',
DOT: '.',
HASH: '#',
NON_ADJACENT_SIBLING: '~',
PSEUDO: ':'
};
var LETTER_PATTERN = /[a-zA-Z]/;
var NOT_PREFIX = ':not(';
var SEPARATOR_PATTERN = /[\s,\(>~\+]/;
function specificity(selector) {
var result = [0, 0, 0];
var character;
var isEscaped;
var isSingleQuoted;
var isDoubleQuoted;
var roundBracketLevel = 0;
var couldIntroduceNewTypeSelector;
var withinNotPseudoClass = false;
var wasPseudoClass = false;
var i, l;
for (i = 0, l = selector.length; i < l; i++) {
character = selector[i];
if (isEscaped) {
// noop
} else if (character == Marker.SINGLE_QUOTE && !isDoubleQuoted && !isSingleQuoted) {
isSingleQuoted = true;
} else if (character == Marker.SINGLE_QUOTE && !isDoubleQuoted && isSingleQuoted) {
isSingleQuoted = false;
} else if (character == Marker.DOUBLE_QUOTE && !isDoubleQuoted && !isSingleQuoted) {
isDoubleQuoted = true;
} else if (character == Marker.DOUBLE_QUOTE && isDoubleQuoted && !isSingleQuoted) {
isDoubleQuoted = false;
} else if (isSingleQuoted || isDoubleQuoted) {
continue;
} else if (roundBracketLevel > 0 && !withinNotPseudoClass) {
// noop
} else if (character == Marker.OPEN_ROUND_BRACKET) {
roundBracketLevel++;
} else if (character == Marker.CLOSE_ROUND_BRACKET && roundBracketLevel == 1) {
roundBracketLevel--;
withinNotPseudoClass = false;
} else if (character == Marker.CLOSE_ROUND_BRACKET) {
roundBracketLevel--;
} else if (character == Selector.HASH) {
result[0]++;
} else if (character == Selector.DOT || character == Marker.OPEN_SQUARE_BRACKET) {
result[1]++;
} else if (character == Selector.PSEUDO && !wasPseudoClass && !isNotPseudoClass(selector, i)) {
result[1]++;
withinNotPseudoClass = false;
} else if (character == Selector.PSEUDO) {
withinNotPseudoClass = true;
} else if ((i === 0 || couldIntroduceNewTypeSelector) && LETTER_PATTERN.test(character)) {
result[2]++;
}
isEscaped = character == Marker.BACK_SLASH;
wasPseudoClass = character == Selector.PSEUDO;
couldIntroduceNewTypeSelector = !isEscaped && SEPARATOR_PATTERN.test(character);
}
return result;
}
function isNotPseudoClass(selector, index) {
return selector.indexOf(NOT_PREFIX, index) === index;
}
module.exports = specificity;