export async function downloadFile()

in src/utils/Utils.ts [58:103]
43 lines of code
6 McCabe index (conditional complexity)

    export async function downloadFile(targetUrl: string, readContent?: boolean, customHeaders?: {}): Promise<string> {
        const tempFilePath: string = getTempOutputPath(targetUrl);
        await fse.ensureFile(tempFilePath);

        return await new Promise((resolve: (res: string) => void, reject: (e: Error) => void): void => {
            const urlObj: url.Url = url.parse(targetUrl);
            const options: object = Object.assign({ headers: Object.assign({}, customHeaders, { "User-Agent": `vscode/${getExtensionVersion()}` }) }, urlObj);
            let client: any;
            if (urlObj.protocol === "https:") {
                client = https;
                // tslint:disable-next-line:no-http-string
            } else if (urlObj.protocol === "http:") {
                client = http;
            } else {
                reject(new Error("Unsupported protocol."));
                return;
            }
            // tslint:disable-next-line: no-unsafe-any
            client.get(options, (res: http.IncomingMessage) => {
                let rawData: string;
                let ws: fse.WriteStream;
                if (readContent) {
                    rawData = "";
                } else {
                    ws = fse.createWriteStream(tempFilePath);
                }
                res.on("data", (chunk: string | Buffer) => {
                    if (readContent) {
                        rawData += chunk;
                    } else {
                        ws.write(chunk);
                    }
                });
                res.on("end", () => {
                    if (readContent) {
                        resolve(rawData);
                    } else {
                        ws.end();
                        resolve(tempFilePath);
                    }
                });
            }).on("error", (err: Error) => {
                reject(err);
            });
        });
    }