feat: execute request and response interceptors.

interceptor.go

@@ -7,3 +7,39 @@ type RequestInterceptor func(*http.Request) error
 
 // ResponseInterceptor is a function to intercept the responses.
 type ResponseInterceptor func(*http.Response) error
+
+// doRequestIntercept executes the request interceptors, it'll terminate if the interceptor
+// function returns an error.
+func (cli *Client) doRequestIntercept(req *http.Request) error {
+	interceptors := cli.reqInterceptors
+	if len(interceptors) == 0 {
+		return nil
+	}
+
+	for _, interceptor := range interceptors {
+		err := interceptor(req)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// doResponseIntercept executes the response interceptors, it'll terminate if the interceptor
+// function returns an error.
+func (cli *Client) doResponseIntercept(resp *http.Response) error {
+	interceptors := cli.respInterceptors
+	if len(interceptors) == 0 {
+		return nil
+	}
+
+	for _, interceptor := range interceptors {
+		err := interceptor(resp)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

request.go

@@ -41,14 +41,38 @@ func (cli *Client) request(method, url string, opts ...RequestOptions) (*http.Re
 	}
 	defer canFunc()
 
-	resp, err := cli.sendRequest(req, opt)
+	resp, err := cli.sendRequestWithInterceptors(req, opt)
 	if err != nil {
 		return resp, err
 	}
 
 	return cli.handleResponse(resp, opt)
 }
 
+// sendRequestWithInterceptors tries to execute the request and response interceptors and
+// sends the request.
+func (cli *Client) sendRequestWithInterceptors(
+	req *http.Request,
+	opt RequestOptions,
+) (*http.Response, error) {
+	err := cli.doRequestIntercept(req)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := cli.sendRequest(req, opt)
+	if err != nil {
+		return nil, err
+	}
+
+	err = cli.doResponseIntercept(resp)
+	if err != nil {
+		return resp, err
+	}
+
+	return resp, nil
+}
+
 // sendRequest gets an HTTP client from the HTTP clients pool and sends the request. It tries to
 // re-send the request when it fails to make the request and the number of attempts is less than
 // the maximum limitation.