Fixes error that appears in the console on drag nested resource to root

[akolson]

Summary

Description of the change(s) you made

This pr fixes a console error that is fired when dragging from a nested resource to its root directory

Manual verification steps performed

1. Create a nested folder structure
2. Drag the inner most folder and drop it into the root directory

Screenshots (if applicable)

Screen.Recording.2023-06-16.at.22.54.06.mov

Does this introduce any tech-debt items?

No

---

Reviewer guidance

How can a reviewer test these changes?

1. Select a particular channel
2. Create a nested folder structure
3. Open your browser console
4. Drag the inner most folder and drop it into the root directory
5. No error described here should be fired

References

Fixes #4112

Comments

---

Contributor's Checklist

PR process:

• If this is an important user-facing change, PR or related issue the CHANGELOG label been added to this PR. Note: items with this label will be added to the CHANGELOG at a later time
• If this includes an internal dependency change, a link to the diff is provided
• The docs label has been added if this introduces a change that needs to be updated in the user docs?
• If any Python requirements have changed, the updated requirements.txt files also included in this PR
• Opportunities for using Google Analytics here are noted
• Migrations are safe for a large db

Studio-specifc:

• All user-facing strings are translated properly
• The notranslate class been added to elements that shouldn't be translated by Google Chrome's automatic translation feature (e.g. icons, user-generated text)
• All UI components are LTR and RTL compliant
• Views are organized into pages, components, and layouts directories as described in the docs
• Users' storage used is recalculated properly on any changes to main tree files
• If there new ways this uses user data that needs to be factored into our Privacy Policy, it has been noted.

Testing:

• Code is clean and well-commented
• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Any new interactions have been added to the QA Sheet
• Critical and brittle code paths are covered by unit tests

---

Reviewer's Checklist

This section is for reviewers to fill out.

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[bjester]

There's still an error popping up, and it's visible in your video:

Only string ID format is supported

I see 2 drop events happening, where one ends up with an undefined/null target. I think we can add defensive check that ignores any drops with a missing target

[akolson]

It looks like identity.metadata.id/payload.target is null/undefined sometimes

const payload = {
    target: identity.metadata.id,
    position,
}

A defensive check has been added to prevent execution of the drop in this instances.

[bjester]

LGTM

[bjester]

In such scenarios where you have to nest a large block of code in a conditional, it can make more sense to have to shortcut the code early instead, which keeps the code flatter. For example:

if (!payload.target) return;

[akolson]

Thanks Blaine! I will most likely refactor this in my next studio PR