Bug of update if the replace parameter is true when use FasterEMA

[nicewookyes]

The function setResult In indicator.ts will export wrong value while the 'replace' parameter is true, beacuse 'this.previousResult' always replaced by 'this.result'. If 'replace' is true in continuous calls to 'update', you will get wrong result after second call

update(_price: BigSource, replace: boolean = false): Big {
    if (!replace) {
      this.pricesCounter++;
    } else if (replace && this.pricesCounter === 0) {
      this.pricesCounter++;
    }
    const price = new Big(_price);

    if (replace && this.previousResult) {
      return this.setResult(
        price.times(this.weightFactor).add(this.previousResult.times(1 - this.weightFactor)),
        replace
      );
    }
    return this.setResult(
      price.times(this.weightFactor).add((this.result ?? price).times(1 - this.weightFactor)),
      replace
    );
  }

  protected setResult(value: number, replace: boolean = false): number {
    if (replace && this.previousHighest !== undefined) {
      this.highest = value > this.previousHighest ? value : this.previousHighest;
    } else if (this.highest === undefined || value > this.highest) {
      this.previousHighest = this.highest;
      this.highest = value;
    }

    if (replace && this.previousLowest) {
      this.lowest = value < this.previousLowest ? value : this.previousLowest;
    } else if (this.lowest === undefined || value < this.lowest) {
      this.previousLowest = this.lowest;
      this.lowest = value;
    }

    this.previousResult = this.result;
    return (this.result = value);
  }

Got correct result after change to this

    if(!replace){
      this.previousResult = this.result;
    }

[bennycode]

Thanks for the hint and the fix. Do you have a little test case in place which I can use? I think I am fixing the issue with #679

[bennycode]

Hi @nicewookyes, I found the issue and fixed it: https://github.com/bennycode/trading-signals/pull/679

I also added test cases for the EMA replace behaviour: https://github.com/bennycode/trading-signals/pull/683

Please install trading-signals@5.0.3 and let me know if it works. 😀