myTweenRef.stop() on 'destroyed' tween throws 'TypeError: this.callbacks is null'

[michalfialadev]

Version

• Phaser Version: 3.60.0-beta.11
• Operating system: any
• Browser: any

Description

ISSUE When creating a Tween and keeping a reference, then after the tween completes and we call: myTweenRef.stop()

app crashes with following error log: TypeError: this.callbacks is null

NOTES

• There might be use-cases for calling myTween.stop() on tween that already finished, or getting better feedback from Phaser that the tween has already finished when calling this code? (maybe not; in my case i run 2 async ops in parallel so i called myTween.stop() 'just in case' it was still running while the other op finished (and tween should be stopped). This worked ok in 3.55.2, stopping the tween (if running), or ignoring the stop() call (if no more running))
• Possibly not to be handled on Phaser side.
• Possibly to be handled by a simple boolean flag check on Phaser side and ignored (avoid error trigger).
• Possibly show warning from Phaser side (will let Phaser creator decide this one)

Example Test Code

NOTE: this.animTween has finished at this point.

console.log(">>>")
console.log(this.animTween.isFinished());       // false
console.log(this.animTween.isActive());         // false
console.log(this.animTween.isDestroyed());      // true
console.log(this.animTween.isPending());        // false
console.log(this.animTween.isPendingRemove());  // false
console.log(this.animTween.isPlaying());        // false
console.log(this.animTween.isRemoved());        // false
console.log(this.animTween.isPaused());         // false
console.log(this.animTween.isSeeking);          // false
console.log(this.animTween.isStartDelayed());   // false
try{
    this.animTween.stop();
}
catch(e:any) {
    console.log(e);
}

////////////////////////////////////// // PHASER code in question that throws //////////////////////////////////////

dispatchEvent: function (event, callback) {
        if (!this.isSeeking) {
            this.emit(event, this, this.targets);
            // following line throws (this.callbacks is null)
            var handler = this.callbacks[callback];
            if (handler) {
                handler.func.apply(this.callbackScope, [ this, this.targets ].concat(handler.params));
            }
        }
    }

Additional Information

[photonstorm]

Thank you for spending time reporting this issue. However, we've already fixed this in the master branch of Phaser, and it will be part of the next beta release.

[photonstorm]

For the record, the stop method now bails if the Tween destroy state has been set. Although really if the Tween is being re-used over and over, it should be set to persist: true in the tween config, but this will at least stop a runtime error.

[michalfialadev]

For the record, the stop method now bails if the Tween destroy state has been set. Although really if the Tween is being re-used over and over, it should be set to persist: true in the tween config, but this will at least stop a runtime error.

persist: true is the proper way to do it, thanks!