frontend: Hide back button with null backLink

[skoeva]

This fix explicitly handles the null case in getBackLink() to ensure that no back button will be shown, as defined in MainInfoSectionProps.

Fixes: #2033

Testing

• Go to frontend/src/components/crd/Details.tsx and set backLink to null in the MainInfoSection component
• Open a cluster in Headlamp (npm start) and navigate to the Custom Resources page
• Click on a CRD and ensure that the back button does not appear on the CRD page

[illume]

I think instead just not adding the backLink would work for this(or backLink=false). If no backLink is supplied, then no back link is used.

Can you please explain a bit more why this is necessary?

[skoeva]

I think instead just not adding the backLink would work for this(or backLink=false). If no backLink is supplied, then no back link is used.

Can you please explain a bit more why this is necessary?

@illume The backLink value is by default the empty string '', and the spec for backLink specifies a difference between passing in the empty string and a null value:

/** The route or location to go to. If it's an empty string, then the "browser back" function is used. If null, no back button will be shown. */

Previously passing in a null value did the same thing as passing in the empty string. Unless this is the intended behavior, we are missing the functionality to handle the null string as specified

[joaquimrocha]

Yeah. By default we have had the backLink, so we should just fix the null case which is what docs mean. The backLink={false} should also be the same as null.

[joaquimrocha]

My comment was in the context of MainInfoSection. You need to account for null there, but checking SectionBox, where it is then used, we shouldn't update it to receive null but instead just pass false to it from MainInfoSection as that's what null means.

[skoeva]

Ran into merge conflict issues...reopening here #2040

[joaquimrocha]

We shouldn't close PRs because of merge conflicts. I am reopening this and closing the new one since this one has the context from previous reviews.

[vyncent-t]

this is a nit but the MainInfoSection part could be left off to make it frontend: Fixes handle null backLink

careful that when changing the commit message it still works

[joaquimrocha]

this is a nit but the MainInfoSection part could be left off to make it frontend: Fixes handle null backLink

Why? I think the only thing not according to format is the first :. Normally we do frontend MainInfoSection: MESSAGE