fix json marshaling error response of azure openai (#343) (#345)

* fix json marshaling error response of azure openai (#343)

* add a test case for handleErrorResp func (#343)

chat_stream_test.go

@@ -255,6 +255,67 @@ func TestCreateChatCompletionStreamRateLimitError(t *testing.T) {
 	t.Logf("%+v\n", apiErr)
 }
 
+func TestAzureCreateChatCompletionStreamRateLimitError(t *testing.T) {
+	wantCode := "429"
+	wantMessage := "Requests to the Creates a completion for the chat message Operation under Azure OpenAI API " +
+		"version 2023-03-15-preview have exceeded token rate limit of your current OpenAI S0 pricing tier. " +
+		"Please retry after 20 seconds. " +
+		"Please go here: https://aka.ms/oai/quotaincrease if you would like to further increase the default rate limit."
+
+	server := test.NewTestServer()
+	server.RegisterHandler("/openai/deployments/gpt-35-turbo/chat/completions",
+		func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusTooManyRequests)
+			// Send test responses
+			dataBytes := []byte(`{"error": { "code": "` + wantCode + `", "message": "` + wantMessage + `"}}`)
+			_, err := w.Write(dataBytes)
+
+			checks.NoError(t, err, "Write error")
+		})
+	// create the test server
+	var err error
+	ts := server.OpenAITestServer()
+	ts.Start()
+	defer ts.Close()
+
+	config := DefaultAzureConfig(test.GetTestToken(), ts.URL)
+	client := NewClientWithConfig(config)
+	ctx := context.Background()
+
+	request := ChatCompletionRequest{
+		MaxTokens: 5,
+		Model:     GPT3Dot5Turbo,
+		Messages: []ChatCompletionMessage{
+			{
+				Role:    ChatMessageRoleUser,
+				Content: "Hello!",
+			},
+		},
+		Stream: true,
+	}
+
+	apiErr := &APIError{}
+	_, err = client.CreateChatCompletionStream(ctx, request)
+	if !errors.As(err, &apiErr) {
+		t.Errorf("Did not return APIError: %+v\n", apiErr)
+		return
+	}
+	if apiErr.HTTPStatusCode != http.StatusTooManyRequests {
+		t.Errorf("Did not return HTTPStatusCode got = %d, want = %d\n", apiErr.HTTPStatusCode, http.StatusTooManyRequests)
+		return
+	}
+	code, ok := apiErr.Code.(string)
+	if !ok || code != wantCode {
+		t.Errorf("Did not return Code. got = %v, want = %s\n", apiErr.Code, wantCode)
+		return
+	}
+	if apiErr.Message != wantMessage {
+		t.Errorf("Did not return Message. got = %s, want = %s\n", apiErr.Message, wantMessage)
+		return
+	}
+}
+
 func TestCreateChatCompletionStreamErrorAccumulatorWriteErrors(t *testing.T) {
 	var err error
 	server := test.NewTestServer()