Merge pull request #3124 from plotly/lib-sort-update

update Lib.sort comment and relax its tests

Author: antoinerg

src/lib/search.js

@@ -118,6 +118,10 @@ exports.roundUp = function(val, arrayIn, reverse) {
 /**
  * Tweak to Array.sort(sortFn) that improves performance for pre-sorted arrays
  *
+ * Note that newer browsers (such as Chrome v70+) are starting to pick up
+ * on pre-sorted arrays which may render the following optimization unnecessary
+ * in the future.
+ *
  * Motivation: sometimes we need to sort arrays but the input is likely to
  * already be sorted. Browsers don't seem to pick up on pre-sorted arrays,
  * and in fact Chrome is actually *slower* sorting pre-sorted arrays than purely

test/jasmine/tests/lib_test.js

@@ -2329,21 +2329,13 @@ describe('Test lib.js:', function() {
                 .toEqual(dupes());
 
             expect(callCount).toEqual(18);
-
-            callCount = 0;
-            dupes().sort(sortCounter);
-            expect(callCount).toBeGreaterThan(18);
         });
 
         it('still short-circuits reversed with duplicates', function() {
             expect(_sort(dupes(), sortCounterReversed))
                 .toEqual(dupes().reverse());
 
             expect(callCount).toEqual(18);
-
-            callCount = 0;
-            dupes().sort(sortCounterReversed);
-            expect(callCount).toBeGreaterThan(18);
         });
     });