fix: guard empty documents list before accessing .first (fixes #778)

[dolliecoder]

Description

Fixes #778

Adds a defensive guard in removeUserFromSubscriberList to prevent a
StateError when accessing response.documents.first if the list is empty.

Previously, calling .first on an empty list could cause a runtime crash.
The method now safely returns early when no matching subscription document exists.

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Type of change

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

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Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• My changes generate no new warnings

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📥 Commits

Reviewing files that changed from the base of the PR and between dd8aba8 and db513f5.

📒 Files selected for processing (1)

• lib/controllers/upcomming_rooms_controller.dart

📝 Walkthrough

Walkthrough

The removeUserFromSubscriberList method in the upcoming rooms controller has been refactored to fetch matching subscriber documents and verify their existence before deletion. Additionally, a field name correction from userID to userId was applied for consistency.

Changes

Cohort / File(s)	Summary
Subscriber Removal Logic lib/controllers/upcomming_rooms_controller.dart	Enhanced removeUserFromSubscriberList method with document fetching and existence validation. Corrected query field from userID to userId and added early return guard to prevent errors when no matching subscription exists.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Poem

🐰 A fix so fine, a guard so neat,
Query fields aligned, the dance complete,
No empty deletions shall pass our way,
The subscriber list is safe to slay! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main fix: guarding against empty documents before accessing .first, which aligns with the code changes that add early return logic and correct the query field.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@lib/controllers/upcomming_rooms_controller.dart`:
- Around line 113-124: The unsubscribe query uses the wrong field name
("userId") causing no matches; change the Query.equal call in the unsubscribe
logic to use "userID" (the same field used elsewhere when writing/reading
subscriptions) so the query that builds response (the block that constructs
Query.equal('userId', authStateController.uid), Query.equal('upcomingRoomId',
upcomingRoomId)) becomes Query.equal('userID', authStateController.uid),
ensuring the response.documents lookup and subsequent subscribeDocument handling
find the correct document.

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ℹ️ Review info

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between bf1dbe2 and dd8aba8.

📒 Files selected for processing (1)

• lib/controllers/upcomming_rooms_controller.dart