[tests] Add tests for formatRelativeDate

[Lauquik]

Which problem is this PR solving?

• Resolves [tests] Another flaky test seems to be introduced #1747

Description of the changes

• added test coverage for formatRelativeDate in /src/utils/date.test.js

How was this change tested?

• manually on my local envrionment

Checklist

• I have read https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
• I have signed all commits
• I have added unit tests for the new functionality
• I have run lint and test steps successfully
  • for jaeger: make lint test
  • for jaeger-ui: yarn lint and yarn test

[yurishkuro]

thanks!

[yurishkuro]

CI failed, not sure if it's related to this change:

FAIL  src/components/TracePage/TraceTimelineViewer/VirtualizedTraceView.test.js
  ● Test suite failed to run

    RangeError: Error while computing Critical Path Algorithm.

      85 |             // Never reaches to default
      86 |             // Something unexpected happened
    > 87 |             throw RangeError(`Error while computing Critical Path Algorithm.`);
         |                   ^
      88 |         }
      89 |       } else {
      90 |         // Drop the child spans of dropped parent span

      at RangeError (src/components/TracePage/CriticalPath/utils/sanitizeOverFlowingChildren.tsx:87:19)
          at Array.forEach (<anonymous>)
      at forEach (src/components/TracePage/CriticalPath/utils/sanitizeOverFlowingChildren.tsx:28:11)
      at TraceCriticalPath (src/components/TracePage/CriticalPath/index.tsx:97:57)
      at apply (../../node_modules/memoize-one/dist/memoize-one.cjs.js:39:[35](https://github.com/jaegertracing/jaeger-ui/actions/runs/6097877025/job/16547274543?pr=1765#step:5:36))
      at src/components/TracePage/TraceTimelineViewer/VirtualizedTraceView.test.js:[37](https://github.com/jaegertracing/jaeger-ui/actions/runs/6097877025/job/16547274543?pr=1765#step:5:38):49
      at Object.describe (src/components/TracePage/TraceTimelineViewer/VirtualizedTraceView.test.js:31:1)

cc @GLVSKiriti

[yurishkuro]

restarted CI, in case it was a spurious error

[codecov]

Codecov Report

Patch has no changes to coverable lines.

📢 Thoughts on this report? Let us know!.

[yurishkuro]

CI succeeded, must have been spurious error - tracked in #1766

[Lauquik]

thanks @yurishkuro