errorMessage is leaked to global scope

[thom-nic]

Mocha (I believe) is detecting variables leaked to global scope. I just upgrade from chai v3.5 to v4.1.2 now I am getting the following test failures:

Error: global leak detected: errorMessage

if I grep -rn errorMessage node_modules/chai I see:

node_modules/chai/chai.js
1513:      errorMessage = msgPrefix + 'the argument to above must be a date';
1515:      errorMessage = msgPrefix + 'the argument to above must be a number';
1518:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1524:      throw new AssertionError(errorMessage, undefined, ssfi);
1609:      errorMessage = msgPrefix + 'the argument to least must be a date';
1611:      errorMessage = msgPrefix + 'the argument to least must be a number';
1614:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1620:      throw new AssertionError(errorMessage, undefined, ssfi);
1704:      errorMessage = msgPrefix + 'the argument to below must be a date';
1706:      errorMessage = msgPrefix + 'the argument to below must be a number';
1709:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1715:      throw new AssertionError(errorMessage, undefined, ssfi);
1799:      errorMessage = msgPrefix + 'the argument to most must be a date';
1801:      errorMessage = msgPrefix + 'the argument to most must be a number';
1804:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1810:      throw new AssertionError(errorMessage, undefined, ssfi);
1898:      errorMessage = msgPrefix + 'the arguments to within must be dates';
1900:      errorMessage = msgPrefix + 'the arguments to within must be numbers';
1903:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1909:      throw new AssertionError(errorMessage, undefined, ssfi);

node_modules/chai/lib/chai/core/assertions.js
1152:      errorMessage = msgPrefix + 'the argument to above must be a date';
1154:      errorMessage = msgPrefix + 'the argument to above must be a number';
1157:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1163:      throw new AssertionError(errorMessage, undefined, ssfi);
1248:      errorMessage = msgPrefix + 'the argument to least must be a date';
1250:      errorMessage = msgPrefix + 'the argument to least must be a number';
1253:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1259:      throw new AssertionError(errorMessage, undefined, ssfi);
1343:      errorMessage = msgPrefix + 'the argument to below must be a date';
1345:      errorMessage = msgPrefix + 'the argument to below must be a number';
1348:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1354:      throw new AssertionError(errorMessage, undefined, ssfi);
1438:      errorMessage = msgPrefix + 'the argument to most must be a date';
1440:      errorMessage = msgPrefix + 'the argument to most must be a number';
1443:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1449:      throw new AssertionError(errorMessage, undefined, ssfi);
1537:      errorMessage = msgPrefix + 'the arguments to within must be dates';
1539:      errorMessage = msgPrefix + 'the arguments to within must be numbers';
1542:      errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
1548:      throw new AssertionError(errorMessage, undefined, ssfi);```

I don't see any var, let or const declaring errorMessage so it appears that indeed it appears to be leaking into the global scope.

[meeber]

Fixed in master via #1040 but not released yet

[acrodrig]

I am getting lots of errors of this types well. Has this made it to a release?

[ricardograca]

@acrodrig Doesn't look like it. The commit where this was fixed isn't in any released version yet.