[Staleness] Error destroying staleness subscriptions when item is removed

[shefalijoshi]

Summary

Navigating away from a component (Plot, Condition Set, LAD Table, LAD Table Set and Telemetry Table) when a telemetry object that has been removed is throwing an error.

Expected vs Current Behavior

There should be no error.

Steps to Reproduce

1. Create any of the above components
2. Put a telemetry object in it
3. Remove the item
4. Then navigate away
5. Observe the console error

TypeError: this.observingStaleness[id] is undefined
    updateStaleness SinewaveStalenessProvider.js:109
    subscribeToStaleness SinewaveStalenessProvider.js:80
    unsubscribe TelemetryAPI.js:409
    triggerUnsubscribeFromStaleness staleness-mixin.js:62
    beforeDestroy staleness-mixin.js:32
    VueJS 27
    destroy OverlayPlotViewProvider.js:79
    clear ObjectView.vue:145
    updateView ObjectView.vue:240

Environment

• Open MCT Version: 2.1.6
• Deployment Type: Testathon
• OS: Mac
• Browser: Firefox

Impact Check List

• Data loss or misrepresented data?
• Regression? Did this used to work or has it always been broken?
• Is there a workaround available?
• Does this impact a critical component?
• Is this just a visual bug with no functional impact?
• Does this block the execution of e2e tests?
• Does this have an impact on Performance?

Additional Information

[jvigliotta]

This is affecting other components as well, the root cause is the same in all cases, will update testing notes when I have more info. EDITED

[jvigliotta]

Testing

• follow the repro steps in the issue description

[rukmini-bose]

Verified Testathon 2/9/23. Don't see anymore console errors

[ozyx]

Verified fixed, Testathon 2/9/2023