Huddle: finding a time that works
A walkthrough of the group-availability ranking function and its test coverage.
View source code ↗Problem
Huddle collects availability for group plans and returns candidate time windows, helping a group move from gathering responses toward a decision.
Constraints
The ranking function handles registered users and token-based responders, repeated responses, empty availability, and plans that have already reached a final state.
Architecture
The function reads a plan and its availability rows, groups available responses by date and slot, deduplicates participant identifiers, and sorts by the number available. It returns the best and runner-up slots. When the configured quorum is reached, it can move the plan from gathering to converging and notify the creator.
Technical tradeoff
The ranking criterion is participant count per slot. It is straightforward to inspect, but equally populated slots have no explicit secondary ranking criterion. The code demonstrates the rule; it does not establish why it was originally selected.
Failure modes & verification
The repository includes tests for empty input, unavailable responses, duplicate participants, anonymous responders, and ranking. The convergence tests mirror the algorithm rather than importing the deployed function, so passing them alone would not prove the deployed route behaves identically. No production incident is asserted here.
Next iteration
Proposed next iteration: share a pure ranking function between the route and tests, define a tie-breaking rule, and add integration tests around state changes and notification delivery.
Evidence & metrics
The repository contains tests, but this walkthrough does not claim they passed or quantify production traffic. Live usage, latency, and reliability figures remain unverified.