unwrap bl children when passed to append() & support bl in constructor

fixes: #26

README.md

@@ -96,7 +96,7 @@ bl.pipe(fs.createWriteStream('gibberish.txt'))
 
 --------------------------------------------------------
 <a name="ctor"></a>
-### new BufferList([ callback | buffer | buffer array ])
+### new BufferList([ callback | Buffer | Buffer array | BufferList | BufferList array | String ])
 The constructor takes an optional callback, if supplied, the callback will be called with an error argument followed by a reference to the **bl** instance, when `bl.end()` is called (i.e. from a piped stream). This is a convenient method of collecting the entire contents of a stream, particularly when the stream is *chunky*, such as a network stream.
 
 Normally, no arguments are required for the constructor, but you can initialise the list by passing in a single `Buffer` object or an array of `Buffer` object.
@@ -120,8 +120,8 @@ Get the length of the list in bytes. This is the sum of the lengths of all of th
 
 --------------------------------------------------------
 <a name="append"></a>
-### bl.append(buffer)
-`append(buffer)` adds an additional buffer or BufferList to the internal list.
+### bl.append(Buffer | Buffer array | BufferList | BufferList array | String)
+`append(buffer)` adds an additional buffer or BufferList to the internal list. `this` is returned so it can be chained.
 
 --------------------------------------------------------
 <a name="get"></a>

bl.js

@@ -24,13 +24,8 @@ function BufferList (callback) {
     this.on('unpipe', function (src) {
       src.removeListener('error', piper)
     })
-  }
-  else if (Buffer.isBuffer(callback))
+  } else {
     this.append(callback)
-  else if (Array.isArray(callback)) {
-    callback.forEach(function (b) {
-      Buffer.isBuffer(b) && this.append(b)
-    }.bind(this))
   }
 
   DuplexStream.call(this)
@@ -49,20 +44,25 @@ BufferList.prototype._offset = function (offset) {
 }
 
 BufferList.prototype.append = function (buf) {
-  var isBuffer = Buffer.isBuffer(buf) ||
-                 buf instanceof BufferList
-
-  // coerce number arguments to strings, since Buffer(number) does
-  // uninitialized memory allocation
-  if (typeof buf == 'number')
-    buf = buf.toString()
-
-  if (buf instanceof BufferList) {
-    this._bufs.push.apply(this._bufs, buf._bufs)
-    this.length += buf.length
-  } else {
-    this._bufs.push(isBuffer ? buf : new Buffer(buf))
-    this.length += buf.length
+  var i = 0
+    , newBuf
+
+  if (Array.isArray(buf)) {
+    for (; i < buf.length; i++)
+      this.append(buf[i])
+  } else if (buf instanceof BufferList) {
+    // unwrap argument into individual BufferLists
+    for (; i < buf._bufs.length; i++)
+      this.append(buf._bufs[i])
+  } else if (buf != null) {
+    // coerce number arguments to strings, since Buffer(number) does
+    // uninitialized memory allocation
+    if (typeof buf == 'number')
+      buf = buf.toString()
+
+    newBuf = Buffer.isBuffer(buf) ? buf : new Buffer(buf)
+    this._bufs.push(newBuf)
+    this.length += newBuf.length
   }
 
   return this

test/test.js

@@ -79,12 +79,39 @@ tape('multiple bytes from multiple buffers', function (t) {
 tape('multiple bytes from multiple buffer lists', function (t) {
   var bl = new BufferList()
 
-  bl.append(new BufferList([new Buffer('abcd'), new Buffer('efg')]))
-  bl.append(new BufferList([new Buffer('hi'), new Buffer('j')]))
+  bl.append(new BufferList([ new Buffer('abcd'), new Buffer('efg') ]))
+  bl.append(new BufferList([ new Buffer('hi'), new Buffer('j') ]))
 
   t.equal(bl.length, 10)
 
   t.equal(bl.slice(0, 10).toString('ascii'), 'abcdefghij')
+
+  t.equal(bl.slice(3, 10).toString('ascii'), 'defghij')
+  t.equal(bl.slice(3, 6).toString('ascii'), 'def')
+  t.equal(bl.slice(3, 8).toString('ascii'), 'defgh')
+  t.equal(bl.slice(5, 10).toString('ascii'), 'fghij')
+
+  t.end()
+})
+
+// same data as previous test, just using nested constructors
+tape('multiple bytes from crazy nested buffer lists', function (t) {
+  var bl = new BufferList()
+
+  bl.append(new BufferList([
+      new BufferList([
+          new BufferList(new Buffer('abc'))
+        , new Buffer('d')
+        , new BufferList(new Buffer('efg'))
+      ])
+    , new BufferList([ new Buffer('hi') ])
+    , new BufferList(new Buffer('j'))
+  ]))
+
+  t.equal(bl.length, 10)
+
+  t.equal(bl.slice(0, 10).toString('ascii'), 'abcdefghij')
+
   t.equal(bl.slice(3, 10).toString('ascii'), 'defghij')
   t.equal(bl.slice(3, 6).toString('ascii'), 'def')
   t.equal(bl.slice(3, 8).toString('ascii'), 'defgh')
@@ -93,6 +120,48 @@ tape('multiple bytes from multiple buffer lists', function (t) {
   t.end()
 })
 
+tape('append accepts arrays of Buffers', function (t) {
+  var bl = new BufferList()
+  bl.append(new Buffer('abc'))
+  bl.append([ new Buffer('def') ])
+  bl.append([ new Buffer('ghi'), new Buffer('jkl') ])
+  bl.append([ new Buffer('mnop'), new Buffer('qrstu'), new Buffer('vwxyz') ])
+  t.equal(bl.length, 26)
+  t.equal(bl.slice().toString('ascii'), 'abcdefghijklmnopqrstuvwxyz')
+  t.end()
+})
+
+tape('append accepts arrays of BufferLists', function (t) {
+  var bl = new BufferList()
+  bl.append(new Buffer('abc'))
+  bl.append([ new BufferList('def') ])
+  bl.append(new BufferList([ new Buffer('ghi'), new BufferList('jkl') ]))
+  bl.append([ new Buffer('mnop'), new BufferList([ new Buffer('qrstu'), new Buffer('vwxyz') ]) ])
+  t.equal(bl.length, 26)
+  t.equal(bl.slice().toString('ascii'), 'abcdefghijklmnopqrstuvwxyz')
+  t.end()
+})
+
+tape('append chainable', function (t) {
+  var bl = new BufferList()
+  t.ok(bl.append(new Buffer('abcd')) === bl)
+  t.ok(bl.append([ new Buffer('abcd') ]) === bl)
+  t.ok(bl.append(new BufferList(new Buffer('abcd'))) === bl)
+  t.ok(bl.append([ new BufferList(new Buffer('abcd')) ]) === bl)
+  t.end()
+})
+
+tape('append chainable (test results)', function (t) {
+  var bl = new BufferList('abc')
+    .append([ new BufferList('def') ])
+    .append(new BufferList([ new Buffer('ghi'), new BufferList('jkl') ]))
+    .append([ new Buffer('mnop'), new BufferList([ new Buffer('qrstu'), new Buffer('vwxyz') ]) ])
+
+  t.equal(bl.length, 26)
+  t.equal(bl.slice().toString('ascii'), 'abcdefghijklmnopqrstuvwxyz')
+  t.end()
+})
+
 tape('consuming from multiple buffers', function (t) {
   var bl = new BufferList()