function computeExpirationTime()

in packages/react-reconciler/src/ReactFiberLane.new.js [330:390]

• 46 lines of code
• 33 McCabe index (conditional complexity)

function computeExpirationTime(lane: Lane, currentTime: number) {
  switch (lane) {
    case SyncLane:
    case InputContinuousHydrationLane:
    case InputContinuousLane:
      // User interactions should expire slightly more quickly.
      //
      // NOTE: This is set to the corresponding constant as in Scheduler.js.
      // When we made it larger, a product metric in www regressed, suggesting
      // there's a user interaction that's being starved by a series of
      // synchronous updates. If that theory is correct, the proper solution is
      // to fix the starvation. However, this scenario supports the idea that
      // expiration times are an important safeguard when starvation
      // does happen.
      return currentTime + 250;
    case DefaultHydrationLane:
    case DefaultLane:
    case TransitionHydrationLane:
    case TransitionLane1:
    case TransitionLane2:
    case TransitionLane3:
    case TransitionLane4:
    case TransitionLane5:
    case TransitionLane6:
    case TransitionLane7:
    case TransitionLane8:
    case TransitionLane9:
    case TransitionLane10:
    case TransitionLane11:
    case TransitionLane12:
    case TransitionLane13:
    case TransitionLane14:
    case TransitionLane15:
    case TransitionLane16:
      return currentTime + 5000;
    case RetryLane1:
    case RetryLane2:
    case RetryLane3:
    case RetryLane4:
    case RetryLane5:
      // TODO: Retries should be allowed to expire if they are CPU bound for
      // too long, but when I made this change it caused a spike in browser
      // crashes. There must be some other underlying bug; not super urgent but
      // ideally should figure out why and fix it. Unfortunately we don't have
      // a repro for the crashes, only detected via production metrics.
      return NoTimestamp;
    case SelectiveHydrationLane:
    case IdleHydrationLane:
    case IdleLane:
    case OffscreenLane:
      // Anything idle priority or lower should never expire.
      return NoTimestamp;
    default:
      if (__DEV__) {
        console.error(
          'Should have found matching lanes. This is a bug in React.',
        );
      }
      return NoTimestamp;
  }
}