Function convertWithItem

packages/graph/src/astToSteps.ts:828–902

* Convert a WITH item AST node to a WithItemConfig.

(item: WithItem)

 * Convert a WITH item AST node to a WithItemConfig.
 */
function convertWithItem(item: WithItem): WithItemConfig {
  const expr = item.expression;

  // Handle null literal: WITH null AS x
  if (expr === null) {
    return {
      type: "expression",
      value: { type: "null" },
      alias: item.alias,
    };
  }

  if (expr.type === "VariableRef") {
    return {
      type: "variable",
      sourceVariable: expr.variable,
      alias: item.alias,
    };
  }

  if (expr.type === "PropertyAccess") {
    return {
      type: "property",
      sourceVariable: expr.variable,
      property: expr.property,
      alias: item.alias,
    };
  }

  if (expr.type === "WithAggregate") {
    return {
      type: "aggregate",
      function: expr.function,
      sourceVariable: expr.variable,
      property: expr.property,
      alias: item.alias,
    };
  }

  if (expr.type === "FunctionCall") {
    // Function calls like type(r), size(list), etc.
    return {
      type: "functionCall",
      functionName: expr.name,
      args: expr.args.map((arg) => convertConditionValue(arg)),
      distinct: expr.distinct,
      alias: item.alias,
    };
  }

  if (expr.type === "ListLiteral") {
    // List literals like [1, 2, 3]
    return {
      type: "expression",
      value: convertConditionValue(expr),
      alias: item.alias,
    };
  }