fix: fix pool start timestamp handling

Signed-off-by: Jérôme Benoit <jerome.benoit@piment-noir.org>

src/pools/abstract-pool.ts

@@ -122,7 +122,7 @@ export abstract class AbstractPool<
  /**
  * The start timestamp of the pool.
  */
- private readonly startTimestamp
+ private startTimestamp?: number
 
  /**
  * Constructs a new poolifier pool.
@@ -177,8 +177,6 @@ export abstract class AbstractPool<
  if (this.opts.startWorkers === true) {
  this.start()
  }
-
- this.startTimestamp = performance.now()
  }
 
  private checkPoolType(): void {
@@ -469,6 +467,9 @@ export abstract class AbstractPool<
  * @returns The pool utilization.
  */
  private get utilization(): number {
+ if (this.startTimestamp == null) {
+ return 0
+ }
  const poolTimeCapacity = (performance.now() - this.startTimestamp) *
  (this.maximumNumberOfWorkers ?? this.minimumNumberOfWorkers)
  const totalTasksRunTime = this.workerNodes.reduce(
@@ -979,6 +980,7 @@ export abstract class AbstractPool<
  }
  this.starting = true
  this.startMinimumNumberOfWorkers()
+ this.startTimestamp = performance.now()
  this.starting = false
  this.started = true
  }
@@ -1004,6 +1006,7 @@ export abstract class AbstractPool<
  new CustomEvent<PoolInfo>(PoolEvents.destroy, { detail: this.info }),
  )
  this.readyEventEmitted = false
+ delete this.startTimestamp
  this.destroying = false
  this.started = false
  }