assert,util: fix sparse array comparison

Comparing sparse arrays did not work properly. That is fixed and tests were added to verify that everything works as expected. This had an impact on `util.isDeepStrictEqual()` and `assert.deepStrictEqual()` and their counterpart `assert.notDeepStrictEqual()`. PR-URL: #24749 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Michaël Zasso <targos@protonmail.com>

Author: BridgeAR

lib/internal/util/comparisons.js

@@ -543,11 +543,10 @@ function objEquiv(a, b, strict, keys, memos, iterationType) {
  } else {
  // Array is sparse.
  const keysA = objectKeys(a);
- i++;
  for (; i < keysA.length; i++) {
  const key = keysA[i];
  if (!hasOwnProperty(b, key) ||
- !innerDeepEqual(a[key], b[i], strict, memos)) {
+ !innerDeepEqual(a[key], b[key], strict, memos)) {
  return false;
  }
  }

test/parallel/test-assert-deep.js

@@ -557,9 +557,20 @@ assertNotDeepOrStrict(
  assertDeepAndStrictEqual(m3, m4);
 }
 
-// Handle sparse arrays
-assertDeepAndStrictEqual([1, , , 3], [1, , , 3]);
-assertOnlyDeepEqual([1, , , 3], [1, , , 3, , , ]);
+// Handle sparse arrays.
+{
+ assertDeepAndStrictEqual([1, , , 3], [1, , , 3]);
+ assertOnlyDeepEqual([1, , , 3], [1, , , 3, , , ]);
+ const a = new Array(3);
+ const b = new Array(3);
+ a[2] = true;
+ b[1] = true;
+ assertNotDeepOrStrict(a, b);
+ b[2] = true;
+ assertNotDeepOrStrict(a, b);
+ a[0] = true;
+ assertNotDeepOrStrict(a, b);
+}
 
 // Handle different error messages
 {