Function resolveConditionValue

packages/graph/src/Steps.ts:1215–1990

* Resolve a condition value - either return the literal value or resolve a reference from the path.

(
  path: TraversalPath<any, any, any>,
  value: ConditionValue,
  context?: QueryContext,
)

 * Resolve a condition value - either return the literal value or resolve a reference from the path.
 */
function resolveConditionValue(
  path: TraversalPath<any, any, any>,
  value: ConditionValue,
  context?: QueryContext,
): any {
  if (value === null || typeof value !== "object") {
    return value;
  }

  // Check if it's a reference object
  if ("type" in value) {
    if (value.type === "null") {
      // Explicit null literal
      return null;
    } else if (value.type === "variableRef") {
      // Resolve variable reference from path
      const variablePath = path.get(value.variable);
      if (!variablePath) {
        return undefined;
      }
      const element = variablePath.value;
      // Handle FOREACH and list comprehension element wrappers
      if (
        element &&
        typeof element === "object" &&
        (element.label === "ForeachElement" || element.label === "ComprehensionElement")
      ) {
        return element.value;
      }
      return element;
    } else if (value.type === "pathRef") {
      // Resolve path reference from path - returns the full TraversalPath
      // This is used for path functions like nodes(p), relationships(p), length(p)
      const variablePath = path.get(value.variable);
      return variablePath; // Return the TraversalPath itself, not its value
    } else if (value.type === "propertyRef") {
      // Resolve property reference from path
      const variablePath = path.get(value.variable);
      if (!variablePath) {
        return undefined;
      }
      let element = variablePath.value;
      // Handle FOREACH and list comprehension element wrappers
      if (
        element &&
        typeof element === "object" &&
        (element.label === "ForeachElement" || element.label === "ComprehensionElement")
      ) {
        element = element.value;
      }
      // Property access on null returns null
      if (element === null) {
        return null;
      }
      if (element instanceof Vertex || element instanceof Edge) {
        return element.get(value.property as never);
      }
      // Handle plain objects (maps) - access property directly