Function buildWithAliasMap

packages/graph/src/astToSteps.ts:3052–3082

* Build a map of aliases from WITH clause items. * Maps alias name → underlying variable/property info.

(items: WithItem[])

 * Maps alias name → underlying variable/property info.
 */
function buildWithAliasMap(items: WithItem[]): Map<string, AliasInfo> {
  const aliasMap = new Map<string, AliasInfo>();

  for (const item of items) {
    const expr = item.expression;
    // Handle null literal: WITH null AS x
    if (expr === null) {
      aliasMap.set(item.alias, {
        variable: item.alias,
      });
    } else if (expr.type === "VariableRef") {
      // Variable reference like `WITH n` or `WITH n AS alias`
      aliasMap.set(item.alias, {
        variable: expr.variable,
      });
    } else if (expr.type === "PropertyAccess") {
      // Property access like `WITH n.name AS name`
      aliasMap.set(item.alias, {
        variable: expr.variable,
        property: expr.property,
      });
    } else {
      // Complex expression (WithAggregate, FunctionCall) - just track the alias itself
      aliasMap.set(item.alias, {
        variable: item.alias,
      });
    }
  }

  return aliasMap;
}

/**
 * Resolve an ORDER BY item to a direction config for OrderStep.