Creating Contribution Graph with only one value returns error

[sinuheshinbr]

If you create a contribution graph with only one date it will return: "rgba(255,82,82, NaN) is not a valid color. Probably due to the fact that opacity is compared with other values to be determined. In this case, I think it is possible to default count to 0 if no other record is provided.

[Andrew-Chen-Wang]

It's not just a single value. Using this data: const contributionData = [{"count": 2, "date": "2021-07-31"}, {"count": 2, "date": "2021-08-01"}]; with an end date of '2021-08-03' also does not work and produces NaN. Weird enough; if you do const contributionData = [{"count": 1, "date": "2021-07-31"}, {"count": 2, "date": "2021-08-01"}]; it works fine.

Anyone know how I could extend the current class to fix this issue temporarily? (Edit OK filed a PR, but here's a temp solution):

function mapValue(
  x: number,
  in_min: number,
  in_max: number,
  out_min: number,
  out_max: number
) {
  return ((x - in_min) * (out_max - out_min)) / (in_max - in_min) + out_min;
}

class Blah extends ContributionGraph {
  getClassNameForIndex(index: number) {
    if (this.state.valueCache[index]) {
      if (this.state.valueCache[index].value) {
        const count = this.state.valueCache[index].value[this.props.accessor];

        if (count) {
          console.log(this.state.minValue,this.state.maxValue);
          const opacity = mapValue(
            count,
            this.state.maxValue === this.state.minValue ? 0: this.state.minValue,
            isNaN(this.state.maxValue) ? 1 : this.state.maxValue,
            0.15 + 0.05, // + 0.05 to make smaller values a bit more visible
            1
          );
          console.log(this.state.minValue, this.state.maxValue,  this.state.maxValue || this.state.minValue, opacity);

          return this.props.chartConfig.color(opacity);
        }
      }
    }

    return this.props.chartConfig.color(0.15);
  }
}