DE-1365 Potential nil panic (#122)

Author: vtopc

.github/workflows/main.yml

@@ -33,9 +33,8 @@ jobs:
       - name: Install deps
         run: go mod download
 
-# TODO(vtopc):
-#      - name: nilaway
-#        run: make nilaway
+      - name: nilaway
+        run: make nilaway
 
 # TODO(vtopc):
 #      - name: lint

.travis.yml

@@ -226,7 +226,11 @@ var NbAttempt = 5
 // doRequest is called to execute the request. Authentification is set
 // with the public key and the secret key specified in MailjetClient.
 func (c *HTTPClient) doRequest(req *http.Request) (resp *http.Response, err error) {
-	debugRequest(req) //DEBUG
+	if req == nil {
+		return nil, fmt.Errorf("req is nil")
+	}
+
+	debugRequest(req) // DEBUG
 	req.SetBasicAuth(c.apiKeyPublic, c.apiKeyPrivate)
 	for attempt := 0; attempt < NbAttempt; attempt++ {
 		if resp != nil {
@@ -237,7 +241,7 @@ func (c *HTTPClient) doRequest(req *http.Request) (resp *http.Response, err erro
 			break
 		}
 	}
-	defer debugResponse(resp) //DEBUG
+	defer debugResponse(resp) // DEBUG
 	if err != nil {
 		return resp, fmt.Errorf("Error getting %s: %s", req.URL, err)
 	}
@@ -247,6 +251,10 @@ func (c *HTTPClient) doRequest(req *http.Request) (resp *http.Response, err erro
 
 // checkResponseError returns response error if the statuscode is < 200 or >= 400.
 func checkResponseError(resp *http.Response) error {
+	if resp == nil {
+		return fmt.Errorf("resp is nil")
+	}
+
 	if resp.StatusCode < 200 || resp.StatusCode >= 400 {
 		var mailjetErr RequestError
 		mailjetErr.StatusCode = resp.StatusCode

core.go

@@ -92,6 +92,10 @@ func (c *HTTPClient) Call() (count, total int, err error) {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
+	if c.request == nil {
+		return 0, 0, fmt.Errorf("request is nil")
+	}
+
 	defer c.reset()
 	for key, value := range c.headers {
 		c.request.Header.Add(key, value)