HDDS-11246. [Recon] Use optional chaining instead of explicit undefined check for Objects in Container and Pipeline Module.

[smitajoshi12]

What changes were proposed in this pull request?

Optinal Chaining for Undefined Checks

Please describe your PR in detail:

Currently we are using explicit undefined checks for statements.
[Sample|https://github.com/apache/ozone/blob/dcfa3b42ba830781de589d13b30162a426ad3a3d/hadoop-ozone/recon/src/main/resources/webapps/recon/ozone-recon-web/src/views/missingContainers/missingContainers.tsx#L401]:
{code:javascript}
Missing${(missingDataSource && missingDataSource.length > 0) ? (${missingDataSource.length})` : ''}
{code}
This causes lots of unnecessary code to be written as guard clauses.
JavaScript offers optional chaining feature which would allow us to skip such checks and make our code more readable.
Optional chaining will short-circuit the check and return undefined if at any step the accessed property is undefined so we do not need to handle so many checks.

The above sample code can be written as:
{code:javascript}
Missing${(missingDataSource?.length > 0) ? (${missingDataSource.length})` : ''}
{code}
where if missingDataSource is undefined, then the expression evaluates to:
{code:javascript}
(undefined > 0)
{code}
which will return false and hence achieve the same result in a more compact syntax

What is the link to the Apache JIRA

(https://issues.apache.org/jira/browse/HDDS-11246)

How was this patch tested?

Manually

[devabhishekpal]

Hi @smitajoshi12, thanks for taking this effort to improve the code quality.
I had a few minor reviews. Please take a look

[devabhishekpal]

Thanks for the changes @smitajoshi12, just another minor change.
Can we use 0 instead of null string?
As in the current change it will show as Missing Containers () in case the data is undefined
Instead it would be better to show it as Missing Containers (0)

Example:
Missing (${missingDataSource?.length ?? 0})

[smitajoshi12]

Thanks for the changes @smitajoshi12, just another minor change. Can we use 0 instead of null string? As in the current change it will show as Missing Containers () in case the data is undefined Instead it would be better to show it as Missing Containers (0)

Example: Missing (${missingDataSource?.length ?? 0})

@devabhishekpal
Done changes in latest commit. 639e4b1

[devabhishekpal]

Thanks @smitajoshi12
These changes look good to me, +1

[devabhishekpal]

Hi @smitajoshi12 , can you please change the heading?

HDDS-11246. Use optional chaining for object undefined checks in Pipelines

[ArafatKhan2198]

Thanks for the patch @smitajoshi12
LGTM +1

[ArafatKhan2198]

@smitajoshi12 please check your fork and resolve the failures in the your CI

[smitajoshi12]

@smitajoshi12 please check your fork and resolve the failures in the your CI

@ArafatKhan2198
After Merge With Master CI Build looks good. You can merge it.

[ArafatKhan2198]

Thanks for the improvement @smitajoshi12
Thanks for the review @devabhishekpal