canIncludeCorrelationHeader()

in shared/AppInsightsCommon/src/Util.ts [337:389]

• 41 lines of code
• 26 McCabe index (conditional complexity)

    canIncludeCorrelationHeader(config: ICorrelationConfig, requestUrl: string, currentHost?: string) {
        if (!requestUrl || (config && config.disableCorrelationHeaders)) {
            return false;
        }

        if (config && config.correlationHeaderExcludePatterns) {
            for (let i = 0; i < config.correlationHeaderExcludePatterns.length; i++) {
                if (config.correlationHeaderExcludePatterns[i].test(requestUrl)) {
                    return false;
                }
            }
        }

        let requestHost = urlParseUrl(requestUrl).host.toLowerCase();
        if (requestHost && (requestHost.indexOf(":443") !== -1 || requestHost.indexOf(":80") !== -1)) {
            // [Bug #1260] IE can include the port even for http and https URLs so if present
            // try and parse it to remove if it matches the default protocol port
            requestHost = (urlParseFullHost(requestUrl, true) || "").toLowerCase();
        }

        if ((!config || !config.enableCorsCorrelation) && (requestHost && requestHost !== currentHost)) {
            return false;
        }

        const includedDomains = config && config.correlationHeaderDomains;
        if (includedDomains) {
            let matchExists: boolean;
            arrForEach(includedDomains, (domain) => {
                const regex = new RegExp(domain.toLowerCase().replace(/\\/g, "\\\\").replace(/\./g, "\\.").replace(/\*/g, ".*"));
                matchExists = matchExists || regex.test(requestHost);
            });

            if (!matchExists) {
                return false;
            }
        }

        const excludedDomains = config && config.correlationHeaderExcludedDomains;
        if (!excludedDomains || excludedDomains.length === 0) {
            return true;
        }

        for (let i = 0; i < excludedDomains.length; i++) {
            const regex = new RegExp(excludedDomains[i].toLowerCase().replace(/\\/g, "\\\\").replace(/\./g, "\\.").replace(/\*/g, ".*"));
            if (regex.test(requestHost)) {
                return false;
            }
        }

        // if we don't know anything about the requestHost, require the user to use included/excludedDomains.
        // Previously we always returned false for a falsy requestHost
        return requestHost && requestHost.length > 0;
    },