async fetch()

in ide/deploy/serve.js [146:207]
50 lines of code
11 McCabe index (conditional complexity)

        async fetch(req) {
            const {pathname} = parse(req.url);
            const filePath = `${assetsDirectory}${pathname === "/" ? "/index.html" : pathname}`;
            // Check if file exists locally
            try {
                // console.debug(`Asset dir: ${assetsDirectory} - Filepath is ${filePath}`);
                const fileStats = statSync(filePath);

                if (fileStats.isFile()) {
                    const mimeType = flags.mimeType || getMimeType(filePath);
                    const headers = {
                        "Content-Type": mimeType,
                    };
                    if (flags.cacheTime) {
                        headers["Cache-Control"] = `max-age=${flags.cacheTime}`;
                    }
                    console.log(`[200] - Serving file ${pathname} from filesystem`);
                    return new Response(readFileSync(filePath), {headers});
                }
            } catch (err) {
                let shouldExclude = (excludedAssets.indexOf(pathname) !== -1);

                // File not found, fall back to proxy
                if (flags.proxyHost && !shouldExclude) {
                    const destProxyUrl = `${flags.proxyHost}${pathname}`;

                    console.log(`[ P ] - Proxying request ${req.method} to '${destProxyUrl}'`);
                    const newHeaders = JSON.parse(JSON.stringify(req.headers));

                    const excludedHeaders = [
                        'host', 'origin',
                        // 'accept-encoding',
                        'sec-fetch-mode', 'sec-fetch-dest', 'sec-ch-ua',
                        'sec-ch-ua-mobile', 'sec-ch-ua-platform', 'sec-fetch-site'
                    ];

                    for (const header of excludedHeaders) {
                        delete newHeaders[header];
                    }

                    const init = {
                        method: req.method,
                        headers: newHeaders,
                    };
                    if (req.method.toLowerCase() !== 'get') {
                        let body = await toBuffer(req.body);
                        body = body.toString('utf8');

                        if (body !== undefined) {
                            init['body'] = body;
                        }
                    }
                    const respP = await fetch(destProxyUrl, init);
                    console.log(`[${respP.status}] - Sending response with status ${respP.statusText}`);

                    return respP;
                } else {
                    console.log(`[404] - File ${pathname} not found`);
                    return new Response("File not found", {status: 404});
                }
            }
        },