Function mapNestedFromQueries

packages/db/src/query/compiler/index.ts:1663–1704

(
  optimizedFrom: QueryIR[`from`],
  originalFrom: QueryIR[`from`],
  queryMapping: QueryMapping,
)

}

function mapNestedFromQueries(
  optimizedFrom: QueryIR[`from`],
  originalFrom: QueryIR[`from`],
  queryMapping: QueryMapping,
): void {
  if (optimizedFrom.type === `unionAll` && originalFrom.type === `unionAll`) {
    for (
      let i = 0;
      i < optimizedFrom.queries.length && i < originalFrom.queries.length;
      i++
    ) {
      const optimizedBranch = optimizedFrom.queries[i]!
      const originalBranch = originalFrom.queries[i]!
      queryMapping.set(optimizedBranch, originalBranch)
      mapNestedQueries(optimizedBranch, originalBranch, queryMapping)
    }
    return
  }

  const optimizedSources = getFromSources(optimizedFrom)
  const originalSources = getFromSources(originalFrom)

  for (
    let i = 0;
    i < optimizedSources.length && i < originalSources.length;
    i++
  ) {
    const optimizedSource = optimizedSources[i]!
    const originalSource = originalSources[i]!
    if (
      optimizedSource.type === `queryRef` &&
      originalSource.type === `queryRef`
    ) {
      queryMapping.set(optimizedSource.query, originalSource.query)
      mapNestedQueries(
        optimizedSource.query,
        originalSource.query,
        queryMapping,
      )
    }
  }
}

/**
 * Follows the given reference in a query