Function projectTaskLedgerEvents

packages/core/src/task-ledger.ts:556–599

(events: readonly TaskLedgerEvent[])

}

export function projectTaskLedgerEvents(events: readonly TaskLedgerEvent[]): TaskLedgerProjection {
  const tasks = new Map<string, TaskLedgerEventTaskSnapshot>();
  const firstSeen = new Map<string, number>();
  const diagnostics: string[] = [];
  for (let eventIndex = 0; eventIndex < events.length; eventIndex += 1) {
    const event = events[eventIndex]!;
    if (!isTaskLedgerEvent(event)) {
      diagnostics.push('invalid task ledger event shape');
      continue;
    }
    const current = tasks.get(event.taskId);
    const typeDiagnostic = validateTaskLedgerEventType(event, current);
    if (typeDiagnostic) diagnostics.push(typeDiagnostic);
    if (event.type === 'task_created' || event.type === 'task_imported') {
      if (current) diagnostics.push(`duplicate ${event.type} for ${event.taskId}`);
      if (!firstSeen.has(event.taskId)) firstSeen.set(event.taskId, eventIndex);
      tasks.set(event.taskId, { ...event.task });
      continue;
    }
    if (!current) {
      diagnostics.push(`task event ${event.type} references unknown task ${event.taskId}`);
      if (!firstSeen.has(event.taskId)) firstSeen.set(event.taskId, eventIndex);
      tasks.set(event.taskId, { ...event.task });
      continue;
    }
    if (event.previousStatus !== undefined && current.status !== event.previousStatus) {
      diagnostics.push(
        `task event ${event.type} for ${event.taskId} expected previous status ${event.previousStatus} but saw ${current.status}`,
      );
    }
    if (
      !canTransitionTaskStatus(current.status, event.nextStatus, {
        explicitReopen: event.type === 'task_reopened',
      })
    ) {
      diagnostics.push(
        `invalid task transition ${current.status} -> ${event.nextStatus} for ${event.taskId}`,
      );
    }
    tasks.set(event.taskId, { ...event.task });
  }
  const hydrated = hydrateTaskLedger([...tasks.values()], firstSeen, diagnostics);
  return { tasks: hydrated.tasks, diagnostics, backfilledTaskIds: hydrated.backfilledTaskIds };
}

function validateTaskLedgerEventType(
  event: TaskLedgerEvent,