CorrectnessCalculator.ts

import { MetricCalculator } from './MetricCalculator';

interface CorrectnessData {
    openBugs: number;
    openPullRequests: number;
    daysSinceLastRelease: number;
    stars: number;
    forks: number;
    watchers: number;
    contributors: number;
}

export class CorrectnessCalculator extends MetricCalculator {
    protected data: CorrectnessData;

    constructor(data: CorrectnessData) {
        super(data);
        this.data = data;
    }

    /**
     * Calculates the correctness metric.
     * @returns a score between 0 and 1, where a higher score indicates better correctness.
     */
    calculate(): number {
        if (!this.validateData()) {
            return 0; // Return 0 if data validation fails
        }

        const {
            openBugs,
            openPullRequests,
            daysSinceLastRelease,
            stars,
            forks,
            watchers,
            contributors,
        } = this.data;

        // Calculate open bugs score (fewer open bugs is better)
        const openBugsScore = openBugs === 0 ? 1 : 1 / (1 + Math.log(openBugs));

        // Calculate activity score based on days since last release (more recent is better)
        const activityScore = daysSinceLastRelease > 0 ? 1 / (1 + Math.log(daysSinceLastRelease)) : 1;

        // Calculate popularity score (more stars, forks, watchers is better)
        const totalPopularity = stars + forks + watchers;
        const popularityScore = 1 - 1 / (1 + Math.log(1 + totalPopularity));

        // Combine the scores
        const correctnessScore = (openBugsScore * 0.4) + (activityScore * 0.3) + (popularityScore * 0.3);

        // Ensure the score is between 0 and 1
        return Number(Math.min(Math.max(correctnessScore, 0), 1).toFixed(2));
    }

    /**
     * Validates the input data.
     */
    override validateData(): boolean {
        const {
            openBugs,
            openPullRequests,
            daysSinceLastRelease,
            stars,
            forks,
            watchers,
            contributors,
        } = this.data;

        return (
            super.validateData() &&
            typeof openBugs === 'number' && openBugs >= 0 &&
            typeof openPullRequests === 'number' && openPullRequests >= 0 &&
            typeof daysSinceLastRelease === 'number' && daysSinceLastRelease >= 0 &&
            typeof stars === 'number' && stars >= 0 &&
            typeof forks === 'number' && forks >= 0 &&
            typeof watchers === 'number' && watchers >= 0 &&
            typeof contributors === 'number' && contributors >= 0
        );
    }
}