Design: Overlapping pub-tender shifts

Generated by /office-hours on 2026-05-06 Reviewed by /plan-eng-review on 2026-05-06 Branch: dghauri0/install-gstack Repo: dghauri0/ihnyc-avi-pub-landing Status: APPROVED (post-eng-review) Mode: Builder

Problem Statement

Two related bugs surface when pub-tender shifts overlap:

Bug 1 — active tender drop. pub.ihnyc-rc.org, /tv, and /ipad show only one tender during an overlap window. Friday example: Dawood 6:30–11:30 PM, Veronica 8:30 PM–2 AM should produce three windows on screen (Dawood only → both → Veronica only); today the second tender is silently dropped from pubTender.activeTenders.

Bug 1B+ (uncovered during eng review) — hours and noteTiming are single-shift artifacts. Even after fixing Bug 1, the TV/iPad footer renders one shift’s hours string and one shift’s countdown. During solo-Dawood (6:30–8:30 PM) the TV would say “pub closes at 11:30” — wrong; Veronica is coming and the actual close is 2 AM. The pub-level fields must reflect the night’s pub-close envelope.

Bug 2 — segmented serving-hours rendering. The “Serving Hours This Week” widget shows "6:40 PM — 11:30 PM, 9:00 PM — 1:40 AM" for Friday. The pub is continuously open 6:40 PM → 1:40 AM; the right rendering is one merged range with the arrow glyph used elsewhere.

Constraints

All three surfaces (/, /ipad, /tv including takeover) must inherit the fix from one worker change.
Visual behavior on TV: same rotation as today; both tenders’ profile slides cycle through the existing rotation. No new UI primitives.
Footer / overlay copy that lists names must include all on-shift tenders.
“Last Call” semantics: pub-closure-relative, owned by whichever shift ends the night. Earlier shifts can leave the Notion Last Call property empty.
iPad surface gets the fix incidentally; deeper iPad polish is out of scope.

Premises

Root cause of Bug 1: findActiveShift (worker.js:3325) returns one shift via .find().
Root cause of Bug 1B+: fetchPubTenderFromNotion (worker.js:3107–3153) derives hours, note, noteTiming from a single activeShift instead of the night’s pub-close envelope.
Root cause of Bug 2: fetchPubHoursWeek (worker.js:3082) joins per-shift formatTimeRange strings with , without merging overlapping intervals.
Notion shift schema is fine as-is; only worker collapse-to-one logic discards data.
All three surfaces consume pubTender.activeTenders and pubTender.noteTiming — a single worker fix covers them.
No new UI is needed for Bug 1 — the existing TV rotation iterates activeTenders[].

Recommended Approach

Approach A from /office-hours (minimal union), refined per /plan-eng-review:

DRY: extract one mergeIntervals(intervals) helper used by both Bug 1B+ (nightly envelope) and Bug 2 (hours widget).
Bug 1: findActiveShift → findActiveShifts — .find() becomes .filter(). Returns Shift[].
Bug 1B+: compute nightly envelope — derive hours and noteTiming from the merged interval that contains now (computeNightlyEnvelope(shifts, now)), not from a single shift.
Bug 2: merge intervals in fetchPubHoursWeek before formatting.
Tighten fetchTenderInfoFromAssignment filter — restrict items to assignment IDs from the active-shift union, not just same-todayISO startDate.
No client changes for /, /ipad, /tv — they all read pubTender.activeTenders[], pubTender.hours, pubTender.noteTiming. Shapes preserved.

Implementation sketch

       Notion shift records (today)
                  │
                  ▼
  shifts = transformShift().filter(overlapsLocalDate)
                  │
                  ├──► Bug 1: findActiveShifts(now) → activeShifts[]
                  │
                  │     ├──► tenderInfo = union over activeShifts.assignmentIds
                  │     │     (existing fetchTenderInfoFromAssignment, dedupeTenderDetails)
                  │     │
                  │     └──► Bug 1B+: envelope = computeNightlyEnvelope(shifts, now)
                  │           ├──► pubTender.hours       = formatTimeRange(envelope.start, envelope.end)
                  │           ├──► pubTender.noteTiming  = derive from shift owning envelope.end
                  │           └──► pubTender.note        = derive same way
                  │
                  └──► Bug 2: fetchPubHoursWeek
                        per-day shifts → mergeIntervals → join(", ")

Pure helpers (testable later)

// Merge sorted intervals; touching boundary (a.end === b.start) merges.
function mergeIntervals(intervals) {
  const sorted = [...intervals].sort((a, b) => a.startDate - b.startDate);
  const merged = [];
  for (const iv of sorted) {
    const last = merged[merged.length - 1];
    if (last && iv.startDate.getTime() <= last.endDate.getTime()) {
      if (iv.endDate.getTime() > last.endDate.getTime()) last.endDate = iv.endDate;
    } else {
      merged.push({ startDate: iv.startDate, endDate: iv.endDate });
    }
  }
  return merged;
}
 
// All currently-active shifts (was: findActiveShift returning one).
function findActiveShifts(shifts, now) {
  const nowMs = now.getTime();
  return shifts.filter((shift) => {
    const startMs = shift.startDate?.getTime();
    const endMs = shift.endDate?.getTime() ?? (startMs ?? 0) + 60 * 60 * 1000;
    return startMs != null && nowMs >= startMs && nowMs < endMs;
  });
}
 
// The merged interval containing `now`. Returns null if none.
// Used to give pubTender.hours / noteTiming the night's pub-close envelope.
function computeNightlyEnvelope(shifts, now) {
  const merged = mergeIntervals(
    shifts.filter((s) => s.endDate && s.endDate > now)
  );
  return merged.find(
    (iv) => iv.startDate.getTime() <= now.getTime() && now.getTime() < iv.endDate.getTime()
  ) || null;
}
 
// Which raw shift owns the envelope's end time? That's the "closing shift" —
// its lastCallMinutes / displayEndDate / etc. populate noteTiming.
function findClosingShift(shifts, envelope) {
  if (!envelope) return null;
  return shifts.find(
    (s) => s.endDate && s.endDate.getTime() === envelope.endDate.getTime()
  ) || null;
}

Wiring in `fetchPubTenderFromNotion`

const activeShifts = findActiveShifts(shifts, now);
if (activeShifts.length === 0) {
  return { /* inactive state, unchanged */ };
}
 
const envelope = computeNightlyEnvelope(shifts, now);
const closingShift = findClosingShift(shifts, envelope) || activeShifts[0];
 
const allAssignmentIds = activeShifts.flatMap((s) => s.assignmentIds || []);
const tenderInfo = await fetchTenderInfoFromAssignment(env, allAssignmentIds, todayISO);
const noteInfo = deriveShiftNote(closingShift, now);
 
return {
  name: tenderInfo.name || "No pub tender assigned",
  hours: formatTimeRange(envelope.startDate, envelope.endDate),
  note: noteInfo.text,
  noteState: noteInfo.state,
  noteTiming: {
    startIso: closingShift.startDate?.toISOString() || "",
    endIso: closingShift.endDate?.toISOString() || "",
    displayStartIso: closingShift.displayStartDate?.toISOString() || "",
    displayEndIso: closingShift.displayEndDate?.toISOString() || "",
    lastCallMinutes:
      typeof closingShift.lastCallMinutes === "number"
        ? closingShift.lastCallMinutes
        : null,
  },
  pageUrl: tenderInfo.pageUrl || "",
  activeTenders: tenderInfo.tenders || [],
};

Tighten `fetchTenderInfoFromAssignment` filter

Replace the items.filter(getDateKeyInTimeZone(item.startDate) === todayISO) heuristic at worker.js:3364 with: pass an expectedAssignmentIds set (or accept items already filtered upstream) and trust the active-shift caller. Avoids the cross-midnight false-positive where an unrelated Saturday shift’s assignment leaks into the union.

Wiring in `fetchPubHoursWeek`

shifts.sort((a, b) => a.startDate - b.startDate);
const merged = mergeIntervals(shifts);
const hoursStr = merged
  .map((s) => formatTimeRange(s.startDate, s.endDate))
  .join(", ");
result.push({ date: dateISO, open: true, hours: hoursStr });

Edge cases

Tender / envelope path:

Single shift active — identical to today (envelope = single shift).
Two overlapping shifts, same tender on both — dedupeTenderDetails keys on id || fullName (worker.js:3636), no duplication.
Two shifts touching at boundary (one ends 11:30, next starts 11:30) — half-open interval [start, end) keeps exactly one active at the boundary instant. Envelope merge uses <=, so they merge into one envelope window.
Shift crossing midnight (Veronica 8:30 PM – 2 AM) — transformShift already handles this; findActiveShifts and the envelope inherit it.
Three or more concurrent shifts — mergeIntervals is sweep-line, handles N.
Zero active shifts — inactive state branch unchanged.
Pre-overlap solo (6:30–8:30 PM Fri) — envelope sees Dawood (active) AND Veronica (upcoming, endDate > now). Merged envelope covers 6:30 PM – 2:00 AM. ✓
Post-midnight Veronica solo — findActiveShifts returns [Veronica], envelope = [Veronica’s window], closingShift = Veronica. ✓
True gap day (6–8 PM, 10 PM–1 AM) at 9:00 PM — findActiveShifts returns []. Inactive state. ✓
True gap day, before the gap (7 PM) — envelope sees first shift only (gap means no merge across). hours = first shift’s window. After-gap second shift kicks in once it becomes active.

Hours widget path:

True overlap → merged single arrow.
Adjacent shifts touching (6–8, 8–10) → merged using <= (decision: merge; nobody experiences the boundary as a closure).
True gap → preserved as two segments; frontend’s multi-segment fallback renders raw string.
Single shift → identical to today.
Sub-shift (one fully inside another) → outer envelope.

Open Questions

None remaining after eng review. (Prior open questions on dedupeTenderDetails keying and TV mosaic resilience were resolved: keys on id || fullName so distinct tenders don’t collapse; existing rotation already iterates activeTenders[].)

Success Criteria

Tender / envelope path:

Friday 7:00 PM (solo): TV/landing footer shows Dawood · 6:30 PM – 2:00 AM (envelope, not Dawood’s 11:30).
Friday 9:00 PM (overlap): footer shows Dawood & Veronica · 6:30 PM – 2:00 AM. TV right rail rotates both profile cards.
Friday 11:45 PM (Veronica solo): footer shows Veronica · 8:30 PM – 2:00 AM. Last call countdown counts down to 2 AM.
1:30 AM Saturday: footer shows Veronica · 8:30 PM – 2:00 AM. Last call active per Veronica’s lastCallMinutes.
Single-tender shifts behave identically to today.

Hours widget path:

Friday row renders 6:40 PM → 1:40 AM (merged), same arrow glyph as Wed/Thu.
A real gap-day still renders both segments.
Sun/Wed/Thu single-shift rows unchanged.

What already exists (reused, not rebuilt)

dedupeTenderDetails (worker.js:3636) — already keys on id || fullName, handles same-tender-on-multiple-shifts.
dedupeStrings + first-name parsing (worker.js:3374–3378) — footer name list already collected from union of items.
fetchTenderInfoFromAssignment already loops over assignment IDs and concatenates names; growing the input list from one shift’s IDs to N shifts’ IDs is the only change at the call site.
TV rotation in syncTakeoverTenderRotation (tv/script.js:1250) already iterates cards of any length.
formatTimeRange (worker.js:3646) emits the en-dash that the frontend split regex [–—-] already handles.

NOT in scope

Per-shift handoff badges (“Dawood until 11:30 · Veronica until 2:00”) — Approach B from /office-hours. Deferred until product asks for it.
Full shift timeline model — Approach C. Overkill for this bug.
Bootstrapping a test framework (vitest + miniflare) — filed as TODO. Manual staging checks acceptable for ship.
iPad rotator polish — separate work.
Notion-side “Last Call” workflow documentation — filed as TODO; logic change implies “Last Call only on closing shift,” and that’s a doc/training change for whoever fills shifts in Notion.

Distribution Plan

Existing Cloudflare Workers deploy via wrangler. No new artifacts.

Dependencies

None. Self-contained worker change.

Worktree parallelization strategy

Sequential implementation — all changes touch worker.js. No parallelization opportunity.

Failure modes (one realistic production failure per new codepath)

Codepath	Failure	Detected?	User-visible?
`findActiveShifts`	Returns shift with corrupt `endDate` (NaN) — predicate skips it; tender silently disappears	No test, no error log	Silent: tender just doesn’t appear
`mergeIntervals`	Sort instability with identical start times (same shift on both database queries)	dedupeTenderDetails downstream catches dup tenders, but envelope could double-count length	Probably not visible
`computeNightlyEnvelope`	`now` falls in a gap between two merged intervals — returns `null` after caller already passed `findActiveShifts`-positive check	Defensive: caller falls back to `activeShifts[0]` envelope	Not visible
`fetchTenderInfoFromAssignment` filter tighten	Active shift has zero `assignmentIds` (data-entry oversight in Notion)	Existing fallback (empty tenders array) → “No pub tender assigned” copy	Visible: existing failure mode, no regression

Critical gaps: None — all failure modes either degrade gracefully or are caught by existing defensive code paths.

The Assignment

Before merging: open /api/events?surface=ipad on staging during a faked overlap (test shift in Notion) and paste the pubTender block into a comment on the PR. Compare against today’s single-tender baseline. The diff should show activeTenders.length go from 1 → 2 and hours show the envelope.

Completion summary

Step 0: Scope Challenge — accepted as-is (1 file, ~50 lines)
Architecture Review: 1 issue raised (1B+ envelope), resolved
Code Quality Review: 2 issues raised (DRY mergeIntervals; tightened filter), both accepted
Test Review: diagram produced, 4 unit-test gaps + 4 manual checks. Unit tests deferred to TODO (no framework).
Performance Review: no issues
NOT in scope: written
What already exists: written
TODOS.md updates: 4 items
Failure modes: 0 critical gaps
Outside voice: skipped (50-line bug fix; not warranted)
Parallelization: sequential, single file
Lake Score: 4/4 chose complete option (DRY helper, envelope, filter tighten, TODOs)

GSTACK REVIEW REPORT

Review	Trigger	Why	Runs	Status	Findings
CEO Review	`/plan-ceo-review`	Scope & strategy	0	—	not run (small bug fix; scope agreed)
Eng Review	`/plan-eng-review`	Architecture & tests (required)	1	CLEAN (PLAN)	3 issues found, all resolved; 0 critical gaps
Design Review	`/plan-design-review`	UI/UX gaps	0	—	not run (no new UI primitives)
Outside Voice	independent challenge	Cross-model check	0	—	skipped (size doesn’t warrant)

UNRESOLVED: 0 VERDICT: ENG CLEARED — ready to implement.

IHNYC RC Platform Docs

Explorer

Design: Overlapping pub-tender shifts

Problem Statement

Constraints

Premises

Recommended Approach

Implementation sketch

Pure helpers (testable later)

Wiring in `fetchPubTenderFromNotion`

Tighten `fetchTenderInfoFromAssignment` filter

Wiring in `fetchPubHoursWeek`

Edge cases

Open Questions

Success Criteria

What already exists (reused, not rebuilt)

NOT in scope

Distribution Plan

Dependencies

Worktree parallelization strategy

Failure modes (one realistic production failure per new codepath)

The Assignment

Completion summary

GSTACK REVIEW REPORT

Graph View

Table of Contents

IHNYC RC Platform Docs

Explorer

Design: Overlapping pub-tender shifts

Problem Statement

Constraints

Premises

Recommended Approach

Implementation sketch

Pure helpers (testable later)

Wiring in fetchPubTenderFromNotion

Tighten fetchTenderInfoFromAssignment filter

Wiring in fetchPubHoursWeek

Edge cases

Open Questions

Success Criteria

What already exists (reused, not rebuilt)

NOT in scope

Distribution Plan

Dependencies

Worktree parallelization strategy

Failure modes (one realistic production failure per new codepath)

The Assignment

Completion summary

GSTACK REVIEW REPORT

Graph View

Table of Contents

Wiring in `fetchPubTenderFromNotion`

Tighten `fetchTenderInfoFromAssignment` filter

Wiring in `fetchPubHoursWeek`