Tests: Fix spurious infinite timer issue

[JasonGore]

Pull request checklist

• Addresses an existing issue: Fixes #0000
• Include a change request file using $ yarn change

Description of changes

Fix spurious infinite timer issue on unit tests due to an issue with jest's runAllTimers and debounce implementations by adding a mock implementation for Async.debounce, similar to the mock for lodash debounce.

I was able to repro the issue by forcibly calling Async.debounce in a unit test, like so:

+import { Async } from '../../Utilities';
 import { mount, ReactWrapper } from 'enzyme';
 import { renderToStaticMarkup } from 'react-dom/server';
 
@@ -412,6 +414,13 @@ describe('TextField with error message', () => {
 
     assertErrorMessage(wrapper.getDOMNode(), errorMessage);
 
+    const AsyncInstance = new Async();
+    const DebounceResultFn2 = AsyncInstance.debounce(() => {
+      console.log('debounced');
+    }, 1000);
+
+    DebounceResultFn2();
+
     wrapper.setProps({ value: '' });
     jest.runAllTimers();

And confirmed that this mock fixed the issue.

Search terms: Ran 100000 timers, and there are still more! Assuming we've hit an infinite recursion and bailing out...

Microsoft Reviewers: Open in CodeFlow

[msft-github-bot]

Perf Analysis

No significant results to display.

All results

Scenario	Master Ticks	PR Ticks	Status
BaseButton	695	707
BaseButton (experiments)	927	918
DefaultButton	972	949
DefaultButton (experiments)	1917	1866
DetailsRow	3259	3458
DetailsRow (fast icons)	3242	3230
DetailsRow without styles	3179	3039
DocumentCardTitle with truncation	1499	1498
MenuButton	1272	1296
MenuButton (experiments)	3376	3502
PrimaryButton	1127	1104
PrimaryButton (experiments)	1864	1855
SplitButton	2731	2718
SplitButton (experiments)	6634	6483
Stack	450	456
Stack with Intrinsic children	1098	1068
Stack with Text children	4018	4157
Text	371	352
Toggle	775	776
Toggle (experiments)	2136	2076
button	54	60

Perf Analysis (Fluent)

Perf comparison

Status	Scenario	Fluent TPI	Fabric TPI	Ratio	Iterations	Ticks
🔧	Avatar.Fluent	0.51	0.49	1.04:1	2000	1022
🎯	Button.Fluent	0.16	0.23	0.7:1	1000	159
🔧	Checkbox.Fluent	0.93	0.4	2.33:1	1000	925
🔧	Dialog.Fluent	0.36	0.25	1.44:1	5000	1818
🔧	Dropdown.Fluent	3.52	0.49	7.18:1	1000	3517
🔧	Icon.Fluent	0.17	0.05	3.4:1	5000	839
🦄	Image.Fluent	0.06	0.1	0.6:1	5000	321
🔧	Slider.Fluent	1.5	0.41	3.66:1	1000	1498
🔧	Text.Fluent	0.07	0.02	3.5:1	5000	366
🦄	Tooltip.Fluent	0.13	13.13	0.01:1	5000	627

🔧 Needs work     🎯 On target     🦄 Amazing

Perf tests with no regressions

Scenario	Current PR Ticks	Baseline Ticks	Ratio
ButtonMinimalPerf.default	164	135	1.21:1
HierarchicalTreeMinimalPerf.default	1235	1085	1.14:1
ListWith60ListItems.default	183	166	1.1:1
TextAreaMinimalPerf.default	3492	3230	1.08:1
ChatWithPopoverPerf.default	606	569	1.07:1
GridMinimalPerf.default	921	860	1.07:1
Text.Fluent	366	343	1.07:1
ChatDuplicateMessagesPerf.default	435	411	1.06:1
LabelMinimalPerf.default	366	350	1.05:1
Checkbox.Fluent	925	878	1.05:1
Tooltip.Fluent	627	599	1.05:1
HeaderSlotsPerf.default	1888	1808	1.04:1
ImageMinimalPerf.default	332	319	1.04:1
ReactionMinimalPerf.default	2533	2440	1.04:1
EmbedMinimalPerf.default	6341	6175	1.03:1
BoxMinimalPerf.default	339	331	1.02:1
DialogMinimalPerf.default	1895	1857	1.02:1
FlexMinimalPerf.default	279	274	1.02:1
HeaderMinimalPerf.default	599	586	1.02:1
ItemLayoutMinimalPerf.default	2223	2181	1.02:1
ListCommonPerf.default	968	948	1.02:1
PortalMinimalPerf.default	300	294	1.02:1
StatusMinimalPerf.default	322	316	1.02:1
TooltipMinimalPerf.default	869	854	1.02:1
TreeWith60ListItems.default	221	216	1.02:1
VideoMinimalPerf.default	944	922	1.02:1
Dropdown.Fluent	3517	3432	1.02:1
Image.Fluent	321	314	1.02:1
AccordionMinimalPerf.default	239	236	1.01:1
AttachmentSlotsPerf.default	3475	3442	1.01:1
AvatarMinimalPerf.default	542	535	1.01:1
DropdownMinimalPerf.default	3571	3526	1.01:1
IconMinimalPerf.default	390	388	1.01:1
ProviderMergeThemesPerf.default	1282	1273	1.01:1
SegmentMinimalPerf.default	1179	1163	1.01:1
SplitButtonMinimalPerf.default	12605	12437	1.01:1
TreeMinimalPerf.default	1238	1225	1.01:1
Avatar.Fluent	1022	1008	1.01:1
FormMinimalPerf.default	984	984	1:1
InputMinimalPerf.default	1087	1082	1:1
MenuButtonMinimalPerf.default	1958	1952	1:1
PopupMinimalPerf.default	418	417	1:1
ProviderMinimalPerf.default	619	622	1:1
ToolbarMinimalPerf.default	1172	1173	1:1
Dialog.Fluent	1818	1811	1:1
Slider.Fluent	1498	1493	1:1
ButtonSlotsPerf.default	737	741	0.99:1
ChatMinimalPerf.default	558	565	0.99:1
DropdownManyItemsPerf.default	367	371	0.99:1
RefMinimalPerf.default	195	197	0.99:1
CustomToolbarPrototype.default	3647	3673	0.99:1
Button.Fluent	159	160	0.99:1
Icon.Fluent	839	850	0.99:1
AnimationMinimalPerf.default	666	681	0.98:1
CarouselMinimalPerf.default	1961	2008	0.98:1
LayoutMinimalPerf.default	680	696	0.98:1
ListMinimalPerf.default	411	421	0.98:1
ListNestedPerf.default	899	919	0.98:1
MenuMinimalPerf.default	2008	2049	0.98:1
RadioGroupMinimalPerf.default	609	623	0.98:1
SliderMinimalPerf.default	1489	1521	0.98:1
AlertMinimalPerf.default	595	617	0.96:1
CheckboxMinimalPerf.default	4077	4251	0.96:1
LoaderMinimalPerf.default	999	1045	0.96:1
TextMinimalPerf.default	377	391	0.96:1
TableMinimalPerf.default	687	726	0.95:1
AttachmentMinimalPerf.default	873	924	0.94:1
DividerMinimalPerf.default	1085	1199	0.9:1

[size-auditor]

Asset size changes

Size Auditor did not detect a change in bundle size for any component!

Baseline commit: f67e451385d5e18b0a704b1be91bc48c1beb78af (build)

[ecraig12345]

Nice! Just one minor comment.