Fix PR #726 adding 'appendTo()' and 'prependTo()'

Some improvements was asked by @jugglinmike for the pull request #726 which was intended to fix issue #641 by adding the two functions 'appendTo()' and 'prependTo()'.
This commit is a continuation of #726 and fixes it.

This is a combination of 5 commits:

- Fix incorrect indentation

- Fix the two test description provided

- Extend arguments for '.appendTo()' and '.prependTo()'

　　　　Based on jQuery documentation, these two functions accept also Node and Array as argument.

　　　　As 'a.appendTo(b)' is actually just 'b.append(a)', the function has to convert the target to a Cheerio object as long as it is not one already.

- Add unit tests to '.appendTo()' and '.prependTo()'

　　　　These test case are intended to verify the correct behavior of functions for different arguments accepted according to the jQuery documentation (htmlString, Cheerio object, Node element, selector or Array of elements).

- Update API documentation with '.appendTo()' and '.prependTo()'

Moreover, there is two more changes which are not directly related:

- Fix one incorrect unit test of '.after()' with Node object

- Rename argument 'content' to 'target' in 'insert[After|Before]()' API

Readme.md

@@ -586,6 +586,20 @@ $.html()
 //    </ul>
 ```
 
+#### .appendTo( target )
+Insert every element in the set of matched elements to the end of the target.
+
+```js
+$('<li class="plum">Plum</li>').appendTo('#fruits')
+$.html()
+//=>  <ul id="fruits">
+//      <li class="apple">Apple</li>
+//      <li class="orange">Orange</li>
+//      <li class="pear">Pear</li>
+//      <li class="plum">Plum</li>
+//    </ul>
+```
+
 #### .prepend( content, [content, ...] )
 Inserts content as the *first* child of each of the selected elements.
 
@@ -600,6 +614,20 @@ $.html()
 //    </ul>
 ```
 
+#### .prependTo( target )
+Insert every element in the set of matched elements to the beginning of the target.
+
+```js
+$('<li class="plum">Plum</li>').prependTo('#fruits')
+$.html()
+//=>  <ul id="fruits">
+//      <li class="plum">Plum</li>
+//      <li class="apple">Apple</li>
+//      <li class="orange">Orange</li>
+//      <li class="pear">Pear</li>
+//    </ul>
+```
+
 #### .after( content, [content, ...] )
 Insert content next to each element in the set of matched elements.
 
@@ -614,7 +642,7 @@ $.html()
 //    </ul>
 ```
 
-#### .insertAfter( content )
+#### .insertAfter( target )
 Insert every element in the set of matched elements after the target.
 
 ```js
@@ -642,7 +670,7 @@ $.html()
 //    </ul>
 ```
 
-#### .insertBefore( content )
+#### .insertBefore( target )
 Insert every element in the set of matched elements before the target.
 
 ```js

lib/api/manipulation.js

@@ -103,23 +103,23 @@ var uniqueSplice = function(array, spliceIdx, spliceCount, newElems, parent) {
 };
 
 exports.appendTo = function(target) {
-	if (typeof target === 'string') {
-		target = this.constructor.call(this.constructor, target, null, this._originalRoot);
-	}
+  if (!target.cheerio) {
+    target = this.constructor.call(this.constructor, target, null, this._originalRoot);
+  }
 
-	target.append(this);
+  target.append(this);
 
-	return this;
+  return this;
 };
 
 exports.prependTo = function(target) {
-	if (typeof target === 'string') {
-		target = this.constructor.call(this.constructor, target, null, this._originalRoot);
-	}
+  if (!target.cheerio) {
+    target = this.constructor.call(this.constructor, target, null, this._originalRoot);
+  }
 
-	target.prepend(this);
+  target.prepend(this);
 
-	return this;
+  return this;
 };
 
 exports.append = _insert(function(dom, children, parent) {

test/api/manipulation.js

@@ -498,20 +498,62 @@ describe('$(...)', function() {
 
   describe('.appendTo', function() {
 
-    it('(Node) : should add element as last child', function() {
+    it('(html) : should add element as last child', function() {
+      var $plum = $('<li class="plum">Plum</li>').appendTo(fruits);
+      expect($plum.parent().children().eq(3).hasClass('plum')).to.be.ok();
+    });
+
+    it('($(...)) : should add element as last child', function() {
       $('<li class="plum">Plum</li>').appendTo($fruits);
       expect($fruits.children().eq(3).hasClass('plum')).to.be.ok();
     });
 
+    it('(Node) : should add element as last child', function() {
+      $('<li class="plum">Plum</li>').appendTo($fruits[0]);
+      expect($fruits.children().eq(3).hasClass('plum')).to.be.ok();
+    });
+
+    it('(selector) : should add element as last child', function() {
+      $('<li class="plum">Plum</li>').appendTo('#fruits');
+      expect($fruits.children().eq(3).hasClass('plum')).to.be.ok();
+    });
+
+    it('(Array) : should add element as last child of all elements in the array', function() {
+      var $multiple = $('<ul><li>Apple</li></ul><ul><li>Orange</li></ul>');
+      $('<li class="plum">Plum</li>').appendTo($multiple.get());
+      expect($multiple.first().children().eq(1).hasClass('plum')).to.be.ok();
+      expect($multiple.last().children().eq(1).hasClass('plum')).to.be.ok();
+    });
   });
 
   describe('.prependTo', function() {
 
     it('(html) : should add element as first child', function() {
+      var $plum = $('<li class="plum">Plum</li>').prependTo(fruits);
+      expect($plum.parent().children().eq(0).hasClass('plum')).to.be.ok();
+    });
+
+    it('($(...)) : should add element as first child', function() {
       $('<li class="plum">Plum</li>').prependTo($fruits);
       expect($fruits.children().eq(0).hasClass('plum')).to.be.ok();
     });
 
+    it('(Node) : should add node as first child', function() {
+      $('<li class="plum">Plum</li>').prependTo($fruits[0]);
+      expect($fruits.children().eq(0).hasClass('plum')).to.be.ok();
+    });
+
+    it('(selector) : should add element as first child', function() {
+      $('<li class="plum">Plum</li>').prependTo('#fruits');
+      expect($fruits.children().eq(0).hasClass('plum')).to.be.ok();
+    });
+
+    it('(Array) : should add element as first child of all elements in the array', function() {
+      var $multiple = $('<ul><li>Apple</li></ul><ul><li>Orange</li></ul>');
+      $('<li class="plum">Plum</li>').prependTo($multiple.get());
+      expect($multiple.first().children().eq(0).hasClass('plum')).to.be.ok();
+      expect($multiple.last().children().eq(0).hasClass('plum')).to.be.ok();
+    });
   });
 
   describe('.after', function() {
@@ -808,7 +850,7 @@ describe('$(...)', function() {
     });
 
     it('(Node) : should add element as previous sibling', function() {
-      var plum = $('<li class="plum">Plum</li>');
+      var plum = $('<li class="plum">Plum</li>')[0];
       $('.apple').before(plum);
       expect($('.apple').prev().hasClass('plum')).to.be.ok();
     });