assert: fix deepEqual/deepStrictEqual on equivalent typed arrays

feross · MylesBorins · commit c5f82b842114 · 2016-12-13T16:25:30.000-05:00
The typed array's underlying ArrayBuffer is used in `Buffer.from`. Let's respect it's .byteOffset or .byteLength (i.e. position within the parent ArrayBuffer). Fixes: #8001 PR-URL: #8002 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Prince John Wesley <princejohnwesley@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
diff --git a/lib/assert.js b/lib/assert.js
@@ -176,8 +176,13 @@ function _deepEqual(actual, expected, strict, memos) {
              pToString(actual) === pToString(expected) &&
              !(actual instanceof Float32Array ||
                actual instanceof Float64Array)) {
-    return compare(new Buffer(actual.buffer),
-                   new Buffer(expected.buffer)) === 0;
+    return compare(
+      new Buffer(actual.buffer).slice(actual.byteOffset,
+                                      actual.byteOffset +
+                                      actual.byteLength),
+      new Buffer(expected.buffer).slice(expected.byteOffset,
+                                        expected.byteOffset +
+                                        expected.byteLength)) === 0;
 
   // 7.5 For all other Object pairs, including Array objects, equivalence is
   // determined by having the same number of owned properties (as verified
