fix: subquestion editor add/move/delete actions causes data drift

[cemreinanc]

problem: deleting group subquestions changes the dates/bounds of the remaining subquestions
Fixes #3571

Summary by CodeRabbit

• Bug Fixes
  • Improved stability and consistency in the question form when adding, duplicating, loading, or managing multiple sub-questions by ensuring each sub-question receives a persistent unique identifier.
  • Prevented list rendering and duplication issues during draft load, cloning, and append operations for sub-questions.

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds a stable per-subquestion clientId (via crypto.randomUUID()) and uses it for React keys. Ensures clientId is assigned on initial render, when loading drafts, cloning, or appending sub-questions to maintain consistent identity.

Changes

Cohort / File(s)	Summary
Sub-question Identifier Stabilization front_end/src/app/(main)/questions/components/group_form.tsx	Introduces an optional clientId on draft sub-questions, generates crypto.randomUUID() for initial, cloned, appended, and draft-loaded sub-questions, and replaces index-based React list keys with subQuestion.clientId. Ensures preserved or newly-created clientId when populating from drafts.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• lsabor
• ncarazon

Poem

🐰 I hop and tag each question true,
A tiny UUID for me and you,
No shifting keys, no scrambled dates,
Stable hops across all states—
Hop hop! 🎉

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: introducing a clientId mechanism to fix data drift issues when adding, moving, or deleting subquestions.
Linked Issues check	✅ Passed	The PR implements a clientId-based tracking system to fix the data drift problem where deleting subquestions caused remaining ones to inherit deleted data, directly addressing issue #3571.
Out of Scope Changes check	✅ Passed	All changes are focused on adding clientId tracking to subquestions and replacing index-based keys with clientId, staying within the scope of fixing issue #3571.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/3571-subquestion-creator-bounds

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No actionable comments were generated in the recent review. 🎉

🧹 Recent nitpick comments

front_end/src/app/(main)/questions/components/group_form.tsx (2)

513-520: Draft backward-compatibility handled well.

The sq.clientId || crypto.randomUUID() fallback ensures older drafts saved without clientId are gracefully upgraded. One minor note: the type cast (sq: QuestionWithForecasts & { clientId?: string }) is loose — the draft's subquestions were originally saved as SubQuestionDraft (via the as unknown as QuestionWithForecasts[] cast on line 547), not true QuestionWithForecasts. This works at runtime but the type isn't quite accurate.

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788-797: Pre-existing: in-place mutation of state objects inside map callbacks.

Throughout the subquestion update handlers (here and at lines 813-818, 838-844, 877-883, 915-921, 933-939), the code mutates the existing subQuestion object rather than creating a new one:

subQuestion["label"] = e.target.value;
return subQuestion;

This mutates React state in-place. It works today because setSubQuestions is called with a new array, triggering re-render. However, with stable keys, React may skip re-rendering children whose reference hasn't changed. Consider using immutable updates (spread into a new object) for safety. This is pre-existing and not introduced by this PR, so fine to defer.

Example immutable update pattern

 setSubQuestions(
   subQuestions.map((subQuestion, iter_index) => {
-    if (index === iter_index) {
-      subQuestion["label"] = e.target.value;
-    }
-    return subQuestion;
+    if (index === iter_index) {
+      return { ...subQuestion, label: e.target.value };
+    }
+    return subQuestion;
   })
 );

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[github-actions]

🧹 Preview Environment Cleaned Up

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Cleanup triggered by PR close at 2026-02-10T09:27:50Z