fix: add friendly errors for hook lifecycle misuse

[bhabishnu]

Resolves #9232

Changes:

• Add a friendly scope error when set() is called outside a hook's begin() / end() block.
• Add a friendly error when a value-returning hook reaches end() without a value.
• Add a friendly error when begin() is called without a matching end().
• Add regression tests for all three cases.

Testing:

• npm test -- test/unit/webgl/p5.Shader.js — 164 passed
• npm run lint — 0 errors (8 existing warnings)
• git diff --check — clean

Screenshots of the change:
N/A

AI usage: Used ChatGPT for debugging and review. Claude Code generated the follow up implementation and regression test changes.

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Continuous Release

CDN link

• https://raw.esm.sh/pr/p5@61c1e35/lib/p5.min.js

Published Packages

• https://pkg.pr.new/p5@61c1e35

Commit hash: 61c1e35

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[davepagurek]

Thanks for making this, it's looking good! One suggestion: we know the name of the hook most of the time, right? Would we be able to make it say like (e.g.) "filterColor requires a value. Make sure to call filterColor.set(value) before filterColor.end()" to be more specific about what the user needs to write?

[bhabishnu]

Thanks for the suggestion. I’ve updated all three lifecycle messages to include the hook name and added a finalColor regression test. All 164 tests in p5.Shader.js pass locally.

I also need to clarify the AI usage: Claude Code generated this follow up implementation and test changes, with ChatGPT assisting with review. I checked the AI Usage Policy afterward and see that this went beyond the assistive use it asks for. How would you prefer me to handle this revision?