Function queryOnce

packages/db/src/query/query-once.ts:90–134

(
  configOrQuery:
    | QueryOnceConfig<TContext>
    | ((
        q: InitialQueryBuilder,
      ) => QueryBuilder<TContext> & RootObjectResultConstraint<TContext>),
)

// Implementation
export async function queryOnce<TContext extends Context>(
  configOrQuery:
    | QueryOnceConfig<TContext>
    | ((
        q: InitialQueryBuilder,
      ) => QueryBuilder<TContext> & RootObjectResultConstraint<TContext>),
): Promise<InferResultType<TContext>> {
  // Normalize input
  const config: QueryOnceConfig<TContext> =
    typeof configOrQuery === `function`
      ? { query: configOrQuery }
      : configOrQuery

  const query = (q: InitialQueryBuilder) => {
    const queryConfig = config.query
    return typeof queryConfig === `function` ? queryConfig(q) : queryConfig
  }

  // Create collection with minimal GC time; preload handles sync start
  const collection = createLiveQueryCollection({
    query,
    gcTime: 1, // Cleanup in next tick when no subscribers (0 disables GC)
  })

  try {
    // Wait for initial data load
    await collection.preload()

    // Check if this is a single-result query (findOne was called)
    const isSingleResult =
      (collection.config as { singleResult?: boolean }).singleResult === true

    // Extract and return results
    if (isSingleResult) {
      const first = collection.values().next().value as
        | InferResultType<TContext>
        | undefined
      return first as InferResultType<TContext>
    }
    return collection.toArray as unknown as InferResultType<TContext>
  } finally {
    // Always cleanup, even on error
    await collection.cleanup()
  }
}