tezx/middleware/cors.js

TezX is a high-performance, lightweight JavaScript framework designed for speed, scalability, and flexibility. It enables efficient routing, middleware management, and static file serving with minimal configuration. Fully compatible with Node.js, Deno, an

export function cors(option = {}) {
    const { methods, allowedHeaders, credentials, exposedHeaders, maxAge, origin, } = option;
    return async function cors(ctx, next) {
        const reqOrigin = ctx.req.headers.get("origin") || "";
        let allowOrigin = "*";
        if (typeof origin === "string") {
            allowOrigin = origin;
        }
        else if (origin instanceof RegExp) {
            allowOrigin = origin.test(reqOrigin) ? reqOrigin : "";
        }
        else if (Array.isArray(origin)) {
            const isAllowed = origin.some((item) => {
                if (typeof item === "string") {
                    return item === reqOrigin;
                }
                else if (item instanceof RegExp) {
                    return item.test(reqOrigin);
                }
            });
            allowOrigin = isAllowed ? reqOrigin : "";
        }
        else if (typeof origin === "function") {
            allowOrigin = origin(reqOrigin) ? reqOrigin : "";
        }
        ctx.headers.set("Access-Control-Allow-Origin", allowOrigin);
        ctx.headers.set("Access-Control-Allow-Methods", (methods || ["GET", "POST", "PUT", "DELETE"]).join(", "));
        ctx.headers.set("Access-Control-Allow-Headers", (allowedHeaders || ["Content-Type", "Authorization"]).join(", "));
        if (exposedHeaders) {
            ctx.headers.set("Access-Control-Expose-Headers", exposedHeaders.join(", "));
        }
        if (credentials) {
            ctx.headers.set("Access-Control-Allow-Credentials", "true");
        }
        if (maxAge) {
            ctx.headers.set("Access-Control-Max-Age", maxAge.toString());
        }
        if (ctx.req.method === "OPTIONS") {
            return new Response(null, {
                status: 204,
                headers: ctx.headers,
            });
        }
        return await next();
    };
}