private _getAgent()

in Extensions/ArtifactEngine/Providers/typed-rest-client/HttpClient.ts [301:373]
55 lines of code
25 McCabe index (conditional complexity)

    private _getAgent(requestUrl: string) {
        let agent;
        let proxy = this._getProxy(requestUrl);
        let useProxy = proxy.proxyUrl && proxy.proxyUrl.hostname && !this._isBypassProxy(requestUrl);

        if (this._keepAlive && useProxy) {
            agent = this._proxyAgent;
        }

        if (this._keepAlive && !useProxy) {
            agent = this._agent;
        }

        // if agent is already assigned use that agent.
        if (!!agent) {
            return agent;
        }

        var parsedUrl = url.parse(requestUrl);
        let usingSsl = parsedUrl.protocol === 'https:';
        let maxSockets = 100;
        if (!!this.requestOptions) {
            maxSockets = this.requestOptions.maxSockets || http.globalAgent.maxSockets
        }

        if (useProxy) {
            var agentOptions: any = {
                maxSockets: maxSockets,
                keepAlive: this._keepAlive,
                proxy: {
                    proxyAuth: proxy.proxyAuth,
                    host: proxy.proxyUrl.hostname,
                    port: proxy.proxyUrl.port
                },
            };

            var tunnelAgent: Function;
            var overHttps = proxy.proxyUrl.protocol === 'https:';
            if (usingSsl) {
                tunnelAgent = overHttps ? tunnel.httpsOverHttps : tunnel.httpsOverHttp;
            } else {
                tunnelAgent = overHttps ? tunnel.httpOverHttps : tunnel.httpOverHttp;
            }

            agent = tunnelAgent(agentOptions);
            this._proxyAgent = agent;
        }

        // if reusing agent across request and tunneling agent isn't assigned create a new agent
        if (this._keepAlive && !agent) {
            var options = { keepAlive: this._keepAlive, maxSockets: maxSockets };
            agent = usingSsl ? new https.Agent(options) : new http.Agent(options);
            this._agent = agent;
        }
        
        // if not using private agent and tunnel agent isn't setup then use global agent
        if(!agent) {
            agent = usingSsl ? https.globalAgent : http.globalAgent;
        }

        if (usingSsl && this._ignoreSslError) {
            // we don't want to set NODE_TLS_REJECT_UNAUTHORIZED=0 since that will affect request for entire process
            // http.RequestOptions doesn't expose a way to modify RequestOptions.agent.options
            // we have to cast it to any and change it directly
            agent.options = Object.assign(agent.options || {}, { rejectUnauthorized: false });
        }

        if (usingSsl && this._certConfig) {
            agent.options = Object.assign(agent.options || {}, { ca: this._ca, cert: this._cert, key: this._key, passphrase: this._certConfig.passphrase });
        }

        return agent;
    }