add .slice() tests for parent tracking/update

diff --git a/index.js b/index.js
index 91bd85a2c0b653cdb8f728ae1780d96e00292c71..b39a62433246ea9ae3e1068a240541505b232bbd 100644 (file)
--- a/index.js
+++ b/index.js
@@ -381,8 +381,6 @@ function _hexSlice (buf, start, end) {
   return out
 }
 
-// TODO: add test that modifying the new buffer slice will modify memory in the
-// original buffer! Use code from:
 // http://nodejs.org/api/buffer.html#buffer_buf_slice_start_end
 Buffer.prototype.slice = function (start, end) {
   var len = this.length
@@ -392,8 +390,6 @@ Buffer.prototype.slice = function (start, end) {
   if (browserSupport) {
     return augment(this.subarray(start, end))
   } else {
-    // TODO: slicing works, with limitations (no parent tracking/update)
-    // https://github.com/feross/native-buffer-browserify/issues/9
     var sliceLen = end - start
     var newBuf = new Buffer(sliceLen, undefined, true)
     for (var i = 0; i < sliceLen; i++) {

diff --git a/test/slice.js b/test/slice.js
new file mode 100644 (file)
index 0000000..2959911
--- /dev/null
+++ b/test/slice.js
@@ -0,0 +1,32 @@
+var B = require('../index.js').Buffer
+var test = require('tape')
+
+test('modifying buffer created by .slice() modifies original memory', function (t) {
+  var buf1 = new Buffer(26)
+  for (var i = 0 ; i < 26 ; i++) {
+    buf1[i] = i + 97 // 97 is ASCII a
+  }
+
+  var buf2 = buf1.slice(0, 3)
+  t.equal(buf2.toString('ascii', 0, buf2.length), 'abc')
+
+  buf2[0] = '!'.charCodeAt(0)
+  t.equal(buf1.toString('ascii', 0, buf2.length), '!bc')
+
+  t.end()
+})
+
+test('modifying parent buffer modifies .slice() buffer\'s memory', function (t) {
+  var buf1 = new Buffer(26)
+  for (var i = 0 ; i < 26 ; i++) {
+    buf1[i] = i + 97 // 97 is ASCII a
+  }
+
+  var buf2 = buf1.slice(0, 3)
+  t.equal(buf2.toString('ascii', 0, buf2.length), 'abc')
+
+  buf1[0] = '!'.charCodeAt(0)
+  t.equal(buf2.toString('ascii', 0, buf2.length), '!bc')
+
+  t.end()
+})