fix: Set Go SDK's User-Agent header (#1285)

Implement AgentTag defined in settings and set Go SDK's outgoing Do requests with the User-Agent header.

Fixes issue: #1274

---------

Co-authored-by: Colin Gooding <[email protected]>

Author: jeremytchang

go/rtl/auth.go

@@ -128,9 +128,16 @@ func (s *AuthSession) Do(result interface{}, method, ver, path string, reqPars m
 		return err
 	}
 
-	// set content-type header
+	// set headers
 	req.Header.Add("Content-Type", contentTypeHeader)
 
+	if s.Config.AgentTag != "" {
+		req.Header.Set("User-Agent", s.Config.AgentTag)
+	}
+	if options != nil && options.AgentTag != "" {
+		req.Header.Set("User-Agent", options.AgentTag)
+	}
+
 	// set query params
 	setQuery(req.URL, reqPars)
 

go/rtl/auth_test.go

@@ -123,6 +123,70 @@ func TestAuthSession_Do_Authorization(t *testing.T) {
 	})
 }
 
+func TestAuthSession_Do_UserAgent(t *testing.T) {
+	const path = "/someMethod"
+	const apiVersion = "/4.0"
+
+	t.Run("Do() sets User-Agent header with AuthSession config's AgentTag", func(t *testing.T) {
+		mux := http.NewServeMux()
+		setupApi40Login(mux, foreverValidTestToken, http.StatusOK)
+		server := httptest.NewServer(mux)
+		defer server.Close()
+
+		mux.HandleFunc("/api"+apiVersion+path, func(w http.ResponseWriter, r *http.Request) {
+			userAgentHeader := r.Header.Get("User-Agent")
+			expectedHeader := "some-agent-tag"
+			if userAgentHeader != expectedHeader {
+				t.Errorf("User-Agent header not correct. got=%v want=%v", userAgentHeader, expectedHeader)
+			}
+		})
+
+		s := NewAuthSession(ApiSettings{
+			BaseUrl:    server.URL,
+			ApiVersion: apiVersion,
+			AgentTag:   "some-agent-tag",
+		})
+
+		var r string
+		err := s.Do(&r, "GET", apiVersion, path, nil, nil, nil)
+
+		if err != nil {
+			t.Errorf("Do() call failed: %v", err)
+		}
+	})
+
+	t.Run("Do() sets User-Agent header with Do's option's AgentTag, which will overwrite  AuthSession config", func(t *testing.T) {
+		mux := http.NewServeMux()
+		setupApi40Login(mux, foreverValidTestToken, http.StatusOK)
+		server := httptest.NewServer(mux)
+		defer server.Close()
+
+		mux.HandleFunc("/api"+apiVersion+path, func(w http.ResponseWriter, r *http.Request) {
+			userAgentHeader := r.Header.Get("User-Agent")
+			expectedHeader := "new-agent-tag"
+			if userAgentHeader != expectedHeader {
+				t.Errorf("User-Agent header not correct. got=%v want=%v", userAgentHeader, expectedHeader)
+			}
+		})
+
+		s := NewAuthSession(ApiSettings{
+			BaseUrl:    server.URL,
+			ApiVersion: apiVersion,
+			AgentTag:   "some-agent-tag",
+		})
+
+		var r string
+		options := ApiSettings{
+			AgentTag:   "new-agent-tag",
+		}
+		err := s.Do(&r, "GET", apiVersion, path, nil, nil, &options)
+
+		if err != nil {
+			t.Errorf("Do() call failed: %v", err)
+		}
+	})
+}
+
 func TestAuthSession_Do_Parse(t *testing.T) {
 	type stringStruct struct {
 		Field *string `json:"field"`