Zero dependency Metric Longest Common Subsequence implementation in js.
npm i metric-lcs
const metriclcs = require("metric-lcs");
console.log(metriclcs("ABDEF", "ABDIF")); //.8Longest Common Subsequence is used with diff, so the metric version of it is suitable for comparing larger strings or for comparing likely subsets of strings since it ignores edit distance and lowers the cost of insertion.
Special thanks to tdebatty for java-string-similarity, which I used as a reference implementation.