Custom Score Function

const index = new FlexSearchIndex({
    resolution: 10,
    score: function(content, term, term_index, partial, partial_index){
        // you'll need to return a number between 0 and "resolution"
        // score is starting from 0, which is the highest score
        // for a resolution of 10 you can return 0 - 9
        // ... 
        return 3;
    } 
});

A common situation is you have some predefined labels which are related to some kind of order, e.g. the importance or priority. A priority label could be high, moderate, low so you can derive the scoring from those properties. Another example is when you have something already ordered and you would like to keep this order as relevance.

Probably you won't need the parameters passed to the score function. But when needed here are the parameters from the score function explained:

1. content is the whole content as an array of terms (encoded)
2. term is the current term which is actually processed (encoded)
3. term_index is the index of the term in the content array
4. partial is the current partial of a term which is actually processed
5. partial_index is the index position of the partial within the term

Partials params are empty when using tokenizer strict. Let's take an example by using the tokenizer full.

The content: "This is an example of partial encoding" The highlighting part marks the partial which is actually processed. Then your score function will called by passing these parameters:

function score(content, term, term_index, partial, partial_index){
    content = ["this", "is", "an", "example", "of", "partial", "encoding"]
    term = "example"
    term_index = 3
    partial = "amp"
    partial_index = 2
} 

Source: doc/customization.md