test: fix interchange debonce test race condition

[ncoden]

Description

Timeout delays are most often not respected and the differences between several timeouts running in parrallel can be huge. To prevent race conditions on slower browsers, we now run the debounce test several time to wait for the debounced event to be called, which may be finally called way after the expected time.

This is done using a new testInterval utility: it try and catch the given function every interval delay, until it succedes (does not throw an error) or a given time passed.

If the debounced event is was called when expected (just after 10ms), we wait and run the test again. If after many tries the debounced event is still not called after 1s, we consider the test as failed.

The test should be now safe enough regarding to race conditions.

Changes

• Add testInterval test utility
• Wait for debounce for slow browsers in Interval debounce test

References

• Improve test: minimize interchange debouce test race condition #11259 - test: minimize interchange debouce test race condition (@ncoden)
• Related to test: give time to IE to render elements before testing focus #11275 - test: give time to IE to render elements before testing focus (@ncoden)

Motivation and Context

Fixes the following race condition with IE11:

[Windows 8.1, Internet Explorer 11.0] Error: "calls reflow on viewport size change once" failed, expected _reflow to be called once but was called 0 times (http://localhost:8888/node_modules/sinon/pkg/sinon-no-sourcemaps.js:165)

-- https://travis-ci.org/zurb/foundation-sites/jobs/379941331#L1128

Types of changes

• Documentation
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing
  functionality to change)

Checklist (all required):

• I have read and follow the CONTRIBUTING document.
• There are no other pull request similar to this one.
• The pull request title is descriptive.
• The template is fully and correctly filled.
• The pull request targets the right branch (develop or support/*).
• My commits are correctly titled and contain all relevant information.
• My code follows the code style of this project.
• I have updated the documentation accordingly to my changes (if relevant).
• I have added tests to cover my changes (if relevant).
• All new and existing tests passed.