handling empty body - just continue with current behaviour and echo s…

…tatus code only

request.go

@@ -91,17 +91,28 @@ func httpRequest(ctx context.Context, client *Client,
 		response.BodyContents, response.Error = ioutil.ReadAll(resp.Body)
 	}
 	// Check status code
-	if http.StatusOK != resp.StatusCode {
-		errBody := struct{
-			Error string `json:"error"`
-		}{}
-		if err := json.Unmarshal(response.BodyContents, &errBody); err != nil{
-			response.Error = fmt.Errorf("failed to unmarshal mapi error response: %w",err)
-		}
+	if http.StatusOK == resp.StatusCode {
+		return
+	}
+	// unexpected status, write an error.
+	if response.BodyContents == nil {
+		// no body so just echo status code.
 		response.Error = fmt.Errorf(
-			"status code: %d does not match %d, error: %s",
-			resp.StatusCode, http.StatusOK, errBody.Error,
+			"status code: %d does not match %d",
+			resp.StatusCode, http.StatusOK,
 		)
+		return
+	}
+	// have a body so map to an error type and add to the error message.
+	errBody := struct {
+		Error string `json:"error"`
+	}{}
+	if err := json.Unmarshal(response.BodyContents, &errBody); err != nil {
+		response.Error = fmt.Errorf("failed to unmarshal mapi error response: %w", err)
 	}
+	response.Error = fmt.Errorf(
+		"status code: %d does not match %d, error: %s",
+		resp.StatusCode, http.StatusOK, errBody.Error,
+	)
 	return
 }