Function diffState

packages/core/src/debug/stateTimeline.ts:163–184

(
  before: T,
  after: T,
)

 * Note: This is a shallow diff - nested objects are compared by reference.
 */
export function diffState<T extends object>(
  before: T,
  after: T,
): Array<{ field: string; before: unknown; after: unknown }> {
  const changes: Array<{ field: string; before: unknown; after: unknown }> = [];
  const allKeys = new Set([...Object.keys(before), ...Object.keys(after)]);

  for (const key of allKeys) {
    const beforeVal = (before as Record<string, unknown>)[key];
    const afterVal = (after as Record<string, unknown>)[key];

    if (beforeVal !== afterVal) {
      changes.push({
        field: key,
        before: beforeVal,
        after: afterVal,
      });
    }
  }

  return changes;
}