add test that exposes bug

lib/block/block.js

@@ -118,6 +118,7 @@ Block._fromBufferReader = function _fromBufferReader(br) {
  * @returns {Block} - An instance of block
  */
 Block.fromBufferReader = function fromBufferReader(br) {
+  $.checkArgument(br, 'br is required');
   var info = Block._fromBufferReader(br);
   return new Block(info);
 };
@@ -127,7 +128,7 @@ Block.fromBufferReader = function fromBufferReader(br) {
  * @returns {Block} - An instance of block
  */
 Block.fromBuffer = function fromBuffer(buf) {
-  return Block.fromBufferReader(BufferReader(buf));
+  return Block.fromBufferReader(new BufferReader(buf));
 };
 
 /**

lib/encoding/bufferreader.js

@@ -13,9 +13,15 @@ var BufferReader = function BufferReader(buf) {
     this.set({
       buf: buf
     });
-  } else if (buf) {
+  } else if (_.isString(buf)) {
+    this.set({
+      buf: new Buffer(buf, 'hex'),
+    });
+  } else if (_.isObject(buf)) {
     var obj = buf;
     this.set(obj);
+  } else {
+    throw new TypeError('Unrecognized argument for BufferReader');
   }
 };