@t8/event-patterns/src/matchPattern.ts

Lightweight event emitter with flexible event type matching

export type MatchParams = Record<string, string | undefined>;

function toObject(x: string[]) {
    return x.reduce<Record<string, unknown>>((p, v, k) => {
        p[String(k)] = v;

        return p;
    }, {});
}

export function matchPattern(pattern: unknown, value: unknown): MatchParams | null {
    if (Array.isArray(pattern)) {
        for (let p of pattern) {
            let matches = matchPattern(p, value);

            if (matches) return matches;
        }

        return null;
    }

    if (pattern instanceof RegExp) {
        let matches = String(value).match(pattern);

        if (matches)
            return {
                ...toObject(Array.from(matches).slice(1)),
                ...matches.groups,
            } as MatchParams;
    }

    if (pattern === '*' || pattern === value)
        return {} as MatchParams;

    return null;
}