The PR looks good overall, but there are a few areas where improvements can be made:

1. In the distanceToScore function, you are checking if the distance is a number and if it's null. However, you are not checking if the distance is a negative number. Negative distances might not make sense in this context, so it would be good to add a check for that.

distanceToScore: function (distance = null) {
  if (distance === null || typeof distance !== "number" || distance < 0) return 0.0;
  if (distance >= 1.0) return 1;
  if (distance <= 0) return 0;
  return 1 - distance;
},

2. In the similarityResponse function, you are pushing the score into the result.scores array. However, you are not checking if the score is a valid number. It would be good to add a check for that.

response.ids[0].forEach((_, i) => {
  result.contextTexts.push(response.documents[0][i]);
  result.sourceDocuments.push(response.metadatas[0][i]);
  const score = this.distanceToScore(response.distances[0][i]);
  if (typeof score === "number" && !isNaN(score)) {
    result.scores.push(score);
  }
});

3. In the similarityResponse function, you are pushing the score into the result.scores array. However, you are not checking if the score is a valid number. It would be good to add a check for that.

response.forEach((item) => {
  const { vector: _, ...rest } = item;
  result.contextTexts.push(rest.text);
  result.sourceDocuments.push(rest);
  if (typeof item.score === "number" && !isNaN(item.score)) {
    result.scores.push(item.score);
  }
});

Please consider these suggestions and update the PR accordingly.