hardhat/src/internal/util/proxy.ts

Hardhat is an extensible developer tool that helps smart contract developers increase productivity by reliably bringing together the tools they want.

export function shouldUseProxy(url: string): boolean {
  const { hostname } = new URL(url);
  const noProxy = process.env.NO_PROXY;

  if (hostname === "localhost" || hostname === "127.0.0.1" || noProxy === "*") {
    return false;
  }

  if (noProxy !== undefined && noProxy !== "") {
    const noProxyList = noProxy.split(",");

    if (noProxyList.includes(hostname)) {
      return false;
    }
  }

  return true;
}