refactor: Refactor endpoint and model compatibility check (#180)

* Add model check for chat stream

* Sync model checks

* Fix typo

* Fix functino

* refactor: Refactor endpoint and model compatibility check

* apply review suggestions

* minor fix

* invert return boolean flag

* fix test

chat.go

@@ -14,7 +14,7 @@ const (
 )
 
 var (
-	ErrChatCompletionInvalidModel       = errors.New("currently, only gpt-3.5-turbo and gpt-3.5-turbo-0301 are supported")                 //nolint:lll
+	ErrChatCompletionInvalidModel       = errors.New("this model is not supported with this method, please use CreateCompletion client method instead") //nolint:lll
 	ErrChatCompletionStreamNotSupported = errors.New("streaming is not supported with this method, please use CreateChatCompletionStream")              //nolint:lll
 )
 
@@ -71,14 +71,12 @@ func (c *Client) CreateChatCompletion(
 		return
 	}
 
-	switch request.Model {
+	urlSuffix := "/chat/completions"
-	case GPT3Dot5Turbo0301, GPT3Dot5Turbo, GPT4, GPT40314, GPT432K0314, GPT432K:
+	if !checkEndpointSupportsModel(urlSuffix, request.Model) {
-	default:
 		err = ErrChatCompletionInvalidModel
 		return
 	}
 
-	urlSuffix := "/chat/completions"
 	req, err := c.requestBuilder.build(ctx, http.MethodPost, c.fullURL(urlSuffix), request)
 	if err != nil {
 		return

chat_stream.go

@@ -37,8 +37,14 @@ func (c *Client) CreateChatCompletionStream(
 	ctx context.Context,
 	request ChatCompletionRequest,
 ) (stream *ChatCompletionStream, err error) {
+	urlSuffix := "/chat/completions"
+	if !checkEndpointSupportsModel(urlSuffix, request.Model) {
+		err = ErrChatCompletionInvalidModel
+		return
+	}
+
 	request.Stream = true
-	req, err := c.newStreamRequest(ctx, "POST", "/chat/completions", request)
+	req, err := c.newStreamRequest(ctx, "POST", urlSuffix, request)
 	if err != nil {
 		return
 	}

chat_stream_test.go

@@ -13,6 +13,28 @@ import (
 	"testing"
 )
 
+func TestChatCompletionsStreamWrongModel(t *testing.T) {
+	config := DefaultConfig("whatever")
+	config.BaseURL = "http://localhost/v1"
+	client := NewClientWithConfig(config)
+	ctx := context.Background()
+
+	req := ChatCompletionRequest{
+		MaxTokens: 5,
+		Model:     "ada",
+		Messages: []ChatCompletionMessage{
+			{
+				Role:    ChatMessageRoleUser,
+				Content: "Hello!",
+			},
+		},
+	}
+	_, err := client.CreateChatCompletionStream(ctx, req)
+	if !errors.Is(err, ErrChatCompletionInvalidModel) {
+		t.Fatalf("CreateChatCompletion should return ErrChatCompletionInvalidModel, but returned: %v", err)
+	}
+}
+
 func TestCreateChatCompletionStream(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/event-stream")

chat_test.go

@@ -34,7 +34,7 @@ func TestChatCompletionsWrongModel(t *testing.T) {
 	}
 	_, err := client.CreateChatCompletion(ctx, req)
 	if !errors.Is(err, ErrChatCompletionInvalidModel) {
-		t.Fatalf("CreateChatCompletion should return wrong model error, but returned: %v", err)
+		t.Fatalf("CreateChatCompletion should return ErrChatCompletionInvalidModel, but returned: %v", err)
 	}
 }
 

completion.go

@@ -45,6 +45,38 @@ const (
 	CodexCodeDavinci001 = "code-davinci-001"
 )
 
+var disabledModelsForEndpoints = map[string]map[string]bool{
+	"/completions": {
+		GPT3Dot5Turbo:     true,
+		GPT3Dot5Turbo0301: true,
+		GPT4:              true,
+		GPT40314:          true,
+		GPT432K:           true,
+		GPT432K0314:       true,
+	},
+	"/chat/completions": {
+		CodexCodeDavinci002:     true,
+		CodexCodeCushman001:     true,
+		CodexCodeDavinci001:     true,
+		GPT3TextDavinci003:      true,
+		GPT3TextDavinci002:      true,
+		GPT3TextCurie001:        true,
+		GPT3TextBabbage001:      true,
+		GPT3TextAda001:          true,
+		GPT3TextDavinci001:      true,
+		GPT3DavinciInstructBeta: true,
+		GPT3Davinci:             true,
+		GPT3CurieInstructBeta:   true,
+		GPT3Curie:               true,
+		GPT3Ada:                 true,
+		GPT3Babbage:             true,
+	},
+}
+
+func checkEndpointSupportsModel(endpoint, model string) bool {
+	return !disabledModelsForEndpoints[endpoint][model]
+}
+
 // CompletionRequest represents a request structure for completion API.
 type CompletionRequest struct {
 	Model            string         `json:"model"`
@@ -105,12 +137,12 @@ func (c *Client) CreateCompletion(
 		return
 	}
 
-	if request.Model == GPT3Dot5Turbo0301 || request.Model == GPT3Dot5Turbo {
+	urlSuffix := "/completions"
+	if !checkEndpointSupportsModel(urlSuffix, request.Model) {
 		err = ErrCompletionUnsupportedModel
 		return
 	}
 
-	urlSuffix := "/completions"
 	req, err := c.requestBuilder.build(ctx, http.MethodPost, c.fullURL(urlSuffix), request)
 	if err != nil {
 		return

request_builder_test.go

@@ -61,7 +61,7 @@ func TestClientReturnsRequestBuilderErrors(t *testing.T) {
 		t.Fatalf("Did not return error when request builder failed: %v", err)
 	}
 
-	_, err = client.CreateChatCompletionStream(ctx, ChatCompletionRequest{})
+	_, err = client.CreateChatCompletionStream(ctx, ChatCompletionRequest{Model: GPT3Dot5Turbo})
 	if !errors.Is(err, errTestRequestBuilderFailed) {
 		t.Fatalf("Did not return error when request builder failed: %v", err)
 	}

stream.go

@@ -22,8 +22,14 @@ func (c *Client) CreateCompletionStream(
 	ctx context.Context,
 	request CompletionRequest,
 ) (stream *CompletionStream, err error) {
+	urlSuffix := "/completions"
+	if !checkEndpointSupportsModel(urlSuffix, request.Model) {
+		err = ErrCompletionUnsupportedModel
+		return
+	}
+
 	request.Stream = true
-	req, err := c.newStreamRequest(ctx, "POST", "/completions", request)
+	req, err := c.newStreamRequest(ctx, "POST", urlSuffix, request)
 	if err != nil {
 		return
 	}

stream_test.go

@@ -12,6 +12,23 @@ import (
 	"testing"
 )
 
+func TestCompletionsStreamWrongModel(t *testing.T) {
+	config := DefaultConfig("whatever")
+	config.BaseURL = "http://localhost/v1"
+	client := NewClientWithConfig(config)
+
+	_, err := client.CreateCompletionStream(
+		context.Background(),
+		CompletionRequest{
+			MaxTokens: 5,
+			Model:     GPT3Dot5Turbo,
+		},
+	)
+	if !errors.Is(err, ErrCompletionUnsupportedModel) {
+		t.Fatalf("CreateCompletion should return ErrCompletionUnsupportedModel, but returned: %v", err)
+	}
+}
+
 func TestCreateCompletionStream(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/event-stream")
@@ -140,7 +157,7 @@ func TestCreateCompletionStreamError(t *testing.T) {
 
 	request := CompletionRequest{
 		MaxTokens: 5,
-		Model:     GPT3Dot5Turbo,
+		Model:     GPT3TextDavinci003,
 		Prompt:    "Hello!",
 		Stream:    true,
 	}