Wrapper function for functions with similar functionality

lib/api/traversing.js

@@ -13,6 +13,62 @@ var isTag = utils.isTag;
 var slice = Array.prototype.slice;
 var reSiblingSelector = /^\s*[~+]/;
 
+/**
+ * Matcher provides function, what finds elements based on function provided. It
+ * also houses filtering. What may provided later when function is called.
+ *
+ * @private
+ * @param {string} name - Function name.
+ * @param {Function} fn - Function for collecting elements.
+ * @returns {Function} - Wrapped function.
+ */
+function _matcher(name, fn) {
+  // customized Map, discards null elements
+  function matchMap(elems) {
+    var len = elems.length;
+    var value;
+    var i = 0;
+    var ret = [];
+    for (; i < len; i++) {
+      value = fn(elems[i], i);
+      if (value !== null) {
+        ret.push(value);
+      }
+    }
+    return Array.prototype.concat.apply([], ret);
+  }
+
+  return function (selector) {
+    if (this[0]) {
+      var matched = matchMap(this);
+
+      // select.filter uses uniqueSort already internally
+      if (selector) {
+        if (typeof selector === 'string') {
+          matched = select.filter(selector, matched, this.options);
+        } else {
+          matched = matched.filter(getFilterFn(selector));
+        }
+      }
+
+      // Sorting happend only if collection had more than one elements
+      if (this.length > 1) {
+        if (!(name === 'next' || name === 'prev' || name === 'children')) {
+          matched = uniqueSort(matched);
+        }
+
+        // Reverse order
+        if (name === 'parents' || name === 'prevAll') {
+          matched.reverse();
+        }
+      }
+
+      return this._make(matched);
+    }
+    return this;
+  };
+}
+
 /**
  * Get the descendants of each element in the current set of matched elements,
  * filtered by a selector, jQuery object, or element.
@@ -70,30 +126,15 @@ exports.find = function (selectorOrHaystack) {
  *   $('.pear').parent().attr('id');
  *   //=> fruits
  *
+ * @function
  * @param {string} [selector] - If specified filter for parent.
  * @returns {Cheerio} The parents.
  * @see {@link https://api.jquery.com/parent/}
  */
-exports.parent = function (selector) {
-  var set = [];
-
-  domEach(this, function (_, elem) {
-    var parentElem = elem.parent;
-    if (
-      parentElem &&
-      parentElem.type !== 'root' &&
-      set.indexOf(parentElem) < 0
-    ) {
-      set.push(parentElem);
-    }
-  });
-
-  if (selector) {
-    set = exports.filter.call(set, selector, this);
-  }
-
-  return this._make(set);
-};
+exports.parent = _matcher('parent', function (elem) {
+  var parent = elem.parent;
+  return parent && parent.type !== 'root' ? parent : null;
+});
 
 /**
  * Get a set of parents filtered by `selector` of each element in the current
@@ -105,30 +146,18 @@ exports.parent = function (selector) {
  *   $('.orange').parents('#fruits').length;
  *   // => 1
  *
+ * @function
  * @param {string} [selector] - If specified filter for parents.
  * @returns {Cheerio} The parents.
  * @see {@link https://api.jquery.com/parents/}
  */
-exports.parents = function (selector) {
-  var parentNodes = [];
-
-  // When multiple DOM elements are in the original set, the resulting set will
-  // be in *reverse* order of the original elements as well, with duplicates
-  // removed.
-  this.get()
-    .reverse()
-    .forEach(function (elem) {
-      traverseParents(this, elem.parent, selector, Infinity).forEach(function (
-        node
-      ) {
-        if (parentNodes.indexOf(node) === -1) {
-          parentNodes.push(node);
-        }
-      });
-    }, this);
-
-  return this._make(parentNodes);
-};
+exports.parents = _matcher('parents', function (elem) {
+  var matched = [];
+  while ((elem = elem.parent) && elem.type !== 'root') {
+    matched.push(elem);
+  }
+  return matched;
+});
 
 /**
  * Get the ancestors of each element in the current set of matched elements, up
@@ -227,29 +256,15 @@ exports.closest = function (selector) {
  *   $('.apple').next().hasClass('orange');
  *   //=> true
  *
+ * @function
  * @param {string} [selector] - If specified filter for sibling.
  * @returns {Cheerio} The next nodes.
  * @see {@link https://api.jquery.com/next/}
  */
-exports.next = function (selector) {
-  if (!this[0]) {
-    return this;
-  }
-  var elems = [];
-
-  domEach(this, function (_, elem) {
-    while ((elem = elem.next)) {
-      if (isTag(elem)) {
-        elems.push(elem);
-        return;
-      }
-    }
-  });
-
-  return selector
-    ? exports.filter.call(elems, selector, this)
-    : this._make(elems);
-};
+exports.next = _matcher('next', function (elem) {
+  while ((elem = elem.next) && !isTag(elem));
+  return elem;
+});
 
 /**
  * Gets all the following siblings of the first selected element, optionally
@@ -261,28 +276,18 @@ exports.next = function (selector) {
  *   $('.apple').nextAll('.orange');
  *   //=> [<li class="orange">Orange</li>]
  *
+ * @function
  * @param {string} [selector] - If specified filter for siblings.
  * @returns {Cheerio} The next nodes.
  * @see {@link https://api.jquery.com/nextAll/}
  */
-exports.nextAll = function (selector) {
-  if (!this[0]) {
-    return this;
+exports.nextAll = _matcher('nextAll', function (elem) {
+  var matched = [];
+  while ((elem = elem.next)) {
+    if (isTag(elem)) matched.push(elem);
   }
-  var elems = [];
-
-  domEach(this, function (_, elem) {
-    while ((elem = elem.next)) {
-      if (isTag(elem) && elems.indexOf(elem) === -1) {
-        elems.push(elem);
-      }
-    }
-  });
-
-  return selector
-    ? exports.filter.call(elems, selector, this)
-    : this._make(elems);
-};
+  return matched;
+});
 
 /**
  * Gets all the following siblings up to but not including the element matched
@@ -342,29 +347,16 @@ exports.nextUntil = function (selector, filterSelector) {
  *   $('.orange').prev().hasClass('apple');
  *   //=> true
  *
+ * @function
  * @param {string} [selector] - If specified filter for siblings.
  * @returns {Cheerio} The previous nodes.
  * @see {@link https://api.jquery.com/prev/}
  */
-exports.prev = function (selector) {
-  if (!this[0]) {
-    return this;
-  }
-  var elems = [];
-
-  domEach(this, function (_, elem) {
-    while ((elem = elem.prev)) {
-      if (isTag(elem)) {
-        elems.push(elem);
-        return;
-      }
-    }
-  });
-
-  return selector
-    ? exports.filter.call(elems, selector, this)
-    : this._make(elems);
-};
+exports.prev = _matcher('prev', function (elem) {
+  // eslint-disable-next-line no-empty
+  while ((elem = elem.prev) && !isTag(elem)) {}
+  return elem;
+});
 
 /**
  * Gets all the preceding siblings of the first selected element, optionally
@@ -376,28 +368,18 @@ exports.prev = function (selector) {
  *   $('.pear').prevAll('.orange');
  *   //=> [<li class="orange">Orange</li>]
  *
+ * @function
  * @param {string} [selector] - If specified filter for siblings.
  * @returns {Cheerio} The previous nodes.
  * @see {@link https://api.jquery.com/prevAll/}
  */
-exports.prevAll = function (selector) {
-  if (!this[0]) {
-    return this;
+exports.prevAll = _matcher('prevAll', function (elem) {
+  var matched = [];
+  while ((elem = elem.prev)) {
+    if (isTag(elem)) matched.push(elem);
   }
-  var elems = [];
-
-  domEach(this, function (_, elem) {
-    while ((elem = elem.prev)) {
-      if (isTag(elem) && elems.indexOf(elem) === -1) {
-        elems.push(elem);
-      }
-    }
-  });
-
-  return selector
-    ? exports.filter.call(elems, selector, this)
-    : this._make(elems);
-};
+  return matched;
+});
 
 /**
  * Gets all the preceding siblings up to but not including the element matched
@@ -459,24 +441,21 @@ exports.prevUntil = function (selector, filterSelector) {
  *   $('.pear').siblings('.orange').length;
  *   //=> 1
  *
+ * @function
  * @param {string} [selector] - If specified filter for siblings.
  * @returns {Cheerio} The siblings.
  * @see {@link https://api.jquery.com/siblings/}
  */
-exports.siblings = function (selector) {
-  var parent = this.parent();
-
-  var elems = (parent ? parent.children() : this.siblingsAndMe())
-    .toArray()
-    .filter(function (elem) {
-      return isTag(elem) && !this.is(elem);
-    }, this);
-
-  if (selector !== undefined) {
-    return exports.filter.call(elems, selector, this);
+exports.siblings = _matcher('siblings', function (elem) {
+  var node = elem.parent && elem.parent.firstChild;
+  var matched = [];
+  for (; node; node = node.next) {
+    if (isTag(node) && node !== elem) {
+      matched.push(node);
+    }
   }
-  return this._make(elems);
-};
+  return matched;
+});
 
 /**
  * Gets the children of the first selected element.
@@ -488,19 +467,14 @@ exports.siblings = function (selector) {
  *   $('#fruits').children('.pear').text();
  *   //=> Pear
  *
+ * @function
  * @param {string} [selector] - If specified filter for children.
  * @returns {Cheerio} The children.
  * @see {@link https://api.jquery.com/children/}
  */
-exports.children = function (selector) {
-  var elems = this.toArray().reduce(function (newElems, elem) {
-    return newElems.concat(elem.children.filter(isTag));
-  }, []);
-
-  if (selector === undefined) return this._make(elems);
-
-  return exports.filter.call(elems, selector, this);
-};
+exports.children = _matcher('children', function (elem) {
+  return elem.children.filter(isTag);
+});
 
 /**
  * Gets the children of each element in the set of matched elements, including

test/__fixtures__/fixtures.js

@@ -46,6 +46,24 @@ exports.drinks = [
   '</ul>',
 ].join('');
 
+exports.eleven = [
+  '<html>\n<body>\n<ul>',
+  '<li>One</li>',
+  '<li>Two</li>',
+  '<li class="blue sel">Three</li>',
+  '<li class="red">Four</li>',
+  '</ul>\n\n<ul>',
+  '<li class="red">Five</li>',
+  '<li>Six</li>',
+  '<li class="blue">Seven</li>',
+  '</ul>\n\n<ul>',
+  '<li>Eight</li>',
+  '<li class="red sel">Nine</li>',
+  '<li>Ten</li>',
+  '<li class="sel">Eleven</li>',
+  '</ul>\n</body>\n</html>',
+].join('\n');
+
 exports.food = [
   '<ul id="food">',
   exports.fruits,