1 files changed, 259 insertions, 0 deletions
diff --git a/node_modules/clean-css/lib/optimizer/level-2/is-mergeable.js b/node_modules/clean-css/lib/optimizer/level-2/is-mergeable.js
new file mode 100644
index 00000000..29049302
--- /dev/null
+++ b/node_modules/clean-css/lib/optimizer/level-2/is-mergeable.js
@@ -0,0 +1,259 @@
+var Marker = require('../../tokenizer/marker');
+var split = require('../../utils/split');
+
+var DEEP_SELECTOR_PATTERN = /\/deep\//;
+var DOUBLE_COLON_PATTERN = /^::/;
+var NOT_PSEUDO = ':not';
+var PSEUDO_CLASSES_WITH_ARGUMENTS = [
+  ':dir',
+  ':lang',
+  ':not',
+  ':nth-child',
+  ':nth-last-child',
+  ':nth-last-of-type',
+  ':nth-of-type'
+];
+var RELATION_PATTERN = /[>\+~]/;
+var UNMIXABLE_PSEUDO_CLASSES = [
+  ':after',
+  ':before',
+  ':first-letter',
+  ':first-line',
+  ':lang'
+];
+var UNMIXABLE_PSEUDO_ELEMENTS = [
+  '::after',
+  '::before',
+  '::first-letter',
+  '::first-line'
+];
+
+var Level = {
+  DOUBLE_QUOTE: 'double-quote',
+  SINGLE_QUOTE: 'single-quote',
+  ROOT: 'root'
+};
+
+function isMergeable(selector, mergeablePseudoClasses, mergeablePseudoElements, multiplePseudoMerging) {
+  var singleSelectors = split(selector, Marker.COMMA);
+  var singleSelector;
+  var i, l;
+
+  for (i = 0, l = singleSelectors.length; i < l; i++) {
+    singleSelector = singleSelectors[i];
+
+    if (singleSelector.length === 0 ||
+        isDeepSelector(singleSelector) ||
+        (singleSelector.indexOf(Marker.COLON) > -1 && !areMergeable(singleSelector, extractPseudoFrom(singleSelector), mergeablePseudoClasses, mergeablePseudoElements, multiplePseudoMerging))) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+function isDeepSelector(selector) {
+  return DEEP_SELECTOR_PATTERN.test(selector);
+}
+
+function extractPseudoFrom(selector) {
+  var list = [];
+  var character;
+  var buffer = [];
+  var level = Level.ROOT;
+  var roundBracketLevel = 0;
+  var isQuoted;
+  var isEscaped;
+  var isPseudo = false;
+  var isRelation;
+  var wasColon = false;
+  var index;
+  var len;
+
+  for (index = 0, len = selector.length; index < len; index++) {
+    character = selector[index];
+
+    isRelation = !isEscaped && RELATION_PATTERN.test(character);
+    isQuoted = level == Level.DOUBLE_QUOTE || level == Level.SINGLE_QUOTE;
+
+    if (isEscaped) {
+      buffer.push(character);
+    } else if (character == Marker.DOUBLE_QUOTE && level == Level.ROOT) {
+      buffer.push(character);
+      level = Level.DOUBLE_QUOTE;
+    } else if (character == Marker.DOUBLE_QUOTE && level == Level.DOUBLE_QUOTE) {
+      buffer.push(character);
+      level = Level.ROOT;
+    } else if (character == Marker.SINGLE_QUOTE && level == Level.ROOT) {
+      buffer.push(character);
+      level = Level.SINGLE_QUOTE;
+    } else if (character == Marker.SINGLE_QUOTE && level == Level.SINGLE_QUOTE) {
+      buffer.push(character);
+      level = Level.ROOT;
+    } else if (isQuoted) {
+      buffer.push(character);
+    } else if (character == Marker.OPEN_ROUND_BRACKET) {
+      buffer.push(character);
+      roundBracketLevel++;
+    } else if (character == Marker.CLOSE_ROUND_BRACKET && roundBracketLevel == 1 && isPseudo) {
+      buffer.push(character);
+      list.push(buffer.join(''));
+      roundBracketLevel--;
+      buffer = [];
+      isPseudo = false;
+    } else if (character == Marker.CLOSE_ROUND_BRACKET) {
+      buffer.push(character);
+      roundBracketLevel--;
+    } else if (character == Marker.COLON && roundBracketLevel === 0 && isPseudo && !wasColon) {
+      list.push(buffer.join(''));
+      buffer = [];
+      buffer.push(character);
+    } else if (character == Marker.COLON && roundBracketLevel === 0 && !wasColon) {
+      buffer = [];
+      buffer.push(character);
+      isPseudo = true;
+    } else if (character == Marker.SPACE && roundBracketLevel === 0 && isPseudo) {
+      list.push(buffer.join(''));
+      buffer = [];
+      isPseudo = false;
+    } else if (isRelation && roundBracketLevel === 0 && isPseudo) {
+      list.push(buffer.join(''));
+      buffer = [];
+      isPseudo = false;
+    } else {
+      buffer.push(character);
+    }
+
+    isEscaped = character == Marker.BACK_SLASH;
+    wasColon = character == Marker.COLON;
+  }
+
+  if (buffer.length > 0 && isPseudo) {
+    list.push(buffer.join(''));
+  }
+
+  return list;
+}
+
+function areMergeable(selector, matches, mergeablePseudoClasses, mergeablePseudoElements, multiplePseudoMerging) {
+  return areAllowed(matches, mergeablePseudoClasses, mergeablePseudoElements) &&
+    needArguments(matches) &&
+    (matches.length < 2 || !someIncorrectlyChained(selector, matches)) &&
+    (matches.length < 2 || multiplePseudoMerging && allMixable(matches));
+}
+
+function areAllowed(matches, mergeablePseudoClasses, mergeablePseudoElements) {
+  var match;
+  var name;
+  var i, l;
+
+  for (i = 0, l = matches.length; i < l; i++) {
+    match = matches[i];
+    name = match.indexOf(Marker.OPEN_ROUND_BRACKET) > -1 ?
+      match.substring(0, match.indexOf(Marker.OPEN_ROUND_BRACKET)) :
+      match;
+
+    if (mergeablePseudoClasses.indexOf(name) === -1 && mergeablePseudoElements.indexOf(name) === -1) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+function needArguments(matches) {
+  var match;
+  var name;
+  var bracketOpensAt;
+  var hasArguments;
+  var i, l;
+
+  for (i = 0, l = matches.length; i < l; i++) {
+    match = matches[i];
+
+    bracketOpensAt = match.indexOf(Marker.OPEN_ROUND_BRACKET);
+    hasArguments = bracketOpensAt > -1;
+    name = hasArguments ?
+      match.substring(0, bracketOpensAt) :
+      match;
+
+    if (hasArguments && PSEUDO_CLASSES_WITH_ARGUMENTS.indexOf(name) == -1) {
+      return false;
+    }
+
+    if (!hasArguments && PSEUDO_CLASSES_WITH_ARGUMENTS.indexOf(name) > -1) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+function someIncorrectlyChained(selector, matches) {
+  var positionInSelector = 0;
+  var match;
+  var matchAt;
+  var nextMatch;
+  var nextMatchAt;
+  var name;
+  var nextName;
+  var areChained;
+  var i, l;
+
+  for (i = 0, l = matches.length; i < l; i++) {
+    match = matches[i];
+    nextMatch = matches[i + 1];
+
+    if (!nextMatch) {
+      break;
+    }
+
+    matchAt = selector.indexOf(match, positionInSelector);
+    nextMatchAt = selector.indexOf(match, matchAt + 1);
+    positionInSelector = nextMatchAt;
+    areChained = matchAt + match.length == nextMatchAt;
+
+    if (areChained) {
+      name = match.indexOf(Marker.OPEN_ROUND_BRACKET) > -1 ?
+        match.substring(0, match.indexOf(Marker.OPEN_ROUND_BRACKET)) :
+        match;
+      nextName = nextMatch.indexOf(Marker.OPEN_ROUND_BRACKET) > -1 ?
+        nextMatch.substring(0, nextMatch.indexOf(Marker.OPEN_ROUND_BRACKET)) :
+        nextMatch;
+
+      if (name != NOT_PSEUDO || nextName != NOT_PSEUDO) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+function allMixable(matches) {
+  var unmixableMatches = 0;
+  var match;
+  var i, l;
+
+  for (i = 0, l = matches.length; i < l; i++) {
+    match = matches[i];
+
+    if (isPseudoElement(match)) {
+      unmixableMatches += UNMIXABLE_PSEUDO_ELEMENTS.indexOf(match) > -1 ? 1 : 0;
+    } else {
+      unmixableMatches += UNMIXABLE_PSEUDO_CLASSES.indexOf(match) > -1 ? 1 : 0;
+    }
+
+    if (unmixableMatches > 1) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+function isPseudoElement(pseudo) {
+  return DOUBLE_COLON_PATTERN.test(pseudo);
+}
+
+module.exports = isMergeable;