git-similarity-index/dist/getSimilarityIndex.js

🔨 Calculates the similarity index between two files.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.getSimilarityIndex = getSimilarityIndex;
const debug_1 = require("debug");
const logger = (0, debug_1.default)("git-similarity-index:bytes");
function isEqualArray(line1, line2) {
    const size1 = line1.length;
    const size2 = line2.length;
    if (size1 !== size2)
        return false;
    for (let i = 0; i < size1; i++) {
        if (line1[i] !== line2[i])
            return false;
    }
    return true;
}
/**
 * Return number of equal lines in bytes
 */
function compareLineBytes(bytes1, bytes2) {
    let sum = 0;
    for (let i = 0; i < bytes1.length; i++) {
        const line1 = bytes1[i];
        for (let j = 0; j < bytes2.length; j++) {
            const line2 = bytes2[j];
            if (isEqualArray(line1, line2)) {
                sum += line1.length;
                bytes2.splice(j, 1);
                break;
            }
        }
    }
    return sum;
}
function getSimilarityIndex(lineBytes1, lineBytes2, size2) {
    logger("Calculating similarity index for bytes", {
        lineBytes1,
        lineBytes2,
        size2,
    });
    const equalLines = compareLineBytes(lineBytes1, lineBytes2);
    const similarityIndex = (equalLines / size2) * 100;
    if (Number.isNaN(similarityIndex)) {
        return 0;
    }
    if (similarityIndex > 100) {
        throw new Error("Similarity index is greater than 100");
    }
    return Number(Number(similarityIndex).toFixed(2));
}