Fixes to append items via toolbar

[getdave]

Closes #18299

Updates the Nav Block toolbar "insert" button to append items at the end of the currently selected Nav Block Item.

Previously this was hardcoded to 0 which meant they were always prepended.

How has this been tested?

Manual testing.

Screenshots

Types of changes

Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR. .

[obenland]

I think the only suggestion I'd have would be to maybe consider destructuring registry to just pick select?

[getdave]

I had some advice from @mcsf that Gutenberg prefers being explicit about where you are accessing the properties of data controls. I took this as avoiding unnecessary destructuring in/around select/dispatch/registry. I could be wrong.

[mcsf]

I had some advice from @mcsf that Gutenberg prefers being explicit about where you are accessing the properties of data controls. I took this as avoiding unnecessary destructuring in/around select/dispatch/registry. I could be wrong.

Thanks for thinking about my advice 😄. In this case I don't really have an opinion, since, in the context of withDispatch, select could only come from one place.

My main point — which was merely stylistic — in the other PR was about not extracting the selectors into their own variable, e.g. const { getFoos } = select( store ), and instead always calling select( store ).getFoos( ...args ).

[getdave]

Waiting on build issues to merge...

[mcsf]

Have you tried calling insertBlock with an undefined index? I had noticed that the argument was considered optional so I tried dropping it, and I think the same effect is achieved.

You can see in the order reducer where index defaults to the substate's length:

gutenberg/packages/block-editor/src/store/reducer.js

Line 731 in bf5c163

const { index = subState.length } = action;

Quick check with @youknowriad: the documentation for insertBlock(s) isn't super explicit about appending when index is missing, but the signature does state "inserted, optionally at a specific index respective a root block list". We can recommend this usage, right?

[mcsf]

I had some advice from @mcsf that Gutenberg prefers being explicit about where you are accessing the properties of data controls. I took this as avoiding unnecessary destructuring in/around select/dispatch/registry. I could be wrong.

Thanks for thinking about my advice 😄. In this case I don't really have an opinion, since, in the context of withDispatch, select could only come from one place.

My main point — which was merely stylistic — in the other PR was about not extracting the selectors into their own variable, e.g. const { getFoos } = select( store ), and instead always calling select( store ).getFoos( ...args ).