Function isLegacyFunctionExpression

packages/graph/src/astToSteps.ts:2537–2562

* Helper to check if an expression is a function call to labels() or type()

(
  item: import("./AST.js").ReturnItem,
)

 * Helper to check if an expression is a function call to labels() or type()
 */
function isLegacyFunctionExpression(
  item: import("./AST.js").ReturnItem,
): { function: "labels" | "type"; variable: string } | null {
  if (item.function && item.variable) {
    return { function: item.function, variable: item.variable };
  }
  const expr = item.expression;
  if (expr && typeof expr === "object" && "type" in expr) {
    if (expr.type === "FunctionCall") {
      const funcCall = expr as FunctionCall;
      const name = funcCall.name.toLowerCase();
      if ((name === "labels" || name === "type") && funcCall.args.length === 1) {
        const arg = funcCall.args[0];
        if (arg && typeof arg === "object" && "type" in arg) {
          if (arg.type === "VariableRef") {
            return {
              function: name as "labels" | "type",
              variable: (arg as import("./AST.js").VariableRef).variable,
            };
          }
        }
      }
    }
  }
  return null;
}

/**
 * Helper to check if an expression is a plain variable reference