Function extractCollectionAliases

packages/db/src/query/live/utils.ts:152–234

(
  query: QueryIR,
)

 * @returns A map from collection ID to the set of all aliases referencing that collection
 */
export function extractCollectionAliases(
  query: QueryIR,
): Map<string, Set<string>> {
  const aliasesById = new Map<string, Set<string>>()

  function recordAlias(source: any) {
    if (!source) return

    if (source.type === `collectionRef`) {
      const { id } = source.collection
      const existing = aliasesById.get(id)
      if (existing) {
        existing.add(source.alias)
      } else {
        aliasesById.set(id, new Set([source.alias]))
      }
    } else if (source.type === `queryRef`) {
      traverse(source.query)
    } else if (source.type === `unionFrom`) {
      for (const childSource of source.sources) {
        recordAlias(childSource)
      }
    } else if (source.type === `unionAll`) {
      for (const branch of source.queries) {
        traverse(branch)
      }
    }
  }

  function traverseSelect(select: any) {
    for (const [key, value] of Object.entries(select)) {
      if (typeof key === `string` && key.startsWith(`__SPREAD_SENTINEL__`)) {
        continue
      }
      if (value instanceof IncludesSubquery) {
        traverse(value.query)
      } else if (value instanceof ConditionalSelect) {
        traverseConditionalSelect(value)
      } else if (isNestedSelectObject(value)) {
        traverseSelect(value)
      }
    }
  }

  function traverseConditionalSelect(conditional: ConditionalSelect) {
    for (const branch of conditional.branches) {
      traverseSelectValue(branch.value)
    }
    if (conditional.defaultValue !== undefined) {
      traverseSelectValue(conditional.defaultValue)
    }
  }

  function traverseSelectValue(value: any) {
    if (value instanceof IncludesSubquery) {
      traverse(value.query)
    } else if (value instanceof ConditionalSelect) {
      traverseConditionalSelect(value)