Repository: sashabaranov/go-openai (go)

Issue:
ChatCompletionRequest with stream: true return EOF
When using ChatCompletionRequest and setting `stream: true` to send multiple conversation content, EOF is returned and no error information can be obtained.

Pull request description:
fix: stream return EOF when openai return error
fix #173 

Patch:
diff --git a/chat_stream.go b/chat_stream.go
index 26e964c..26c4bfc 100644
--- a/chat_stream.go
+++ b/chat_stream.go
@@ -2,11 +2,7 @@ package openai
 
 import (
 	"bufio"
-	"bytes"
 	"context"
-	"encoding/json"
-	"io"
-	"net/http"
 )
 
 type ChatCompletionStreamChoiceDelta struct {
@@ -30,52 +26,7 @@ type ChatCompletionStreamResponse struct {
 // ChatCompletionStream
 // Note: Perhaps it is more elegant to abstract Stream using generics.
 type ChatCompletionStream struct {
-	emptyMessagesLimit uint
-	isFinished         bool
-
-	reader   *bufio.Reader
-	response *http.Response
-}
-
-func (stream *ChatCompletionStream) Recv() (response ChatCompletionStreamResponse, err error) {
-	if stream.isFinished {
-		err = io.EOF
-		return
-	}
-
-	var emptyMessagesCount uint
-
-waitForData:
-	line, err := stream.reader.ReadBytes('\n')
-	if err != nil {
-		return
-	}
-
-	var headerData = []byte("data: ")
-	line = bytes.TrimSpace(line)
-	if !bytes.HasPrefix(line, headerData) {
-		emptyMessagesCount++
-		if emptyMessagesCount > stream.emptyMessagesLimit {
-			err = ErrTooManyEmptyStreamMessages
-			return
-		}
-
-		goto waitForData
-	}
-
-	line = bytes.TrimPrefix(line, headerData)
-	if string(line) == "[DONE]" {
-		stream.isFinished = true
-		err = io.EOF
-		return
-	}
-
-	err = json.Unmarshal(line, &response)
-	return
-}
-
-func (stream *ChatCompletionStream) Close() {
-	stream.response.Body.Close()
+	*streamReader[ChatCompletionStreamResponse]
 }
 
 // CreateChatCompletionStream — API call to create a chat completion w/ streaming
@@ -98,9 +49,13 @@ func (c *Client) CreateChatCompletionStream(
 	}
 
 	stream = &ChatCompletionStream{
-		emptyMessagesLimit: c.config.EmptyMessagesLimit,
-		reader:             bufio.NewReader(resp.Body),
-		response:           resp,
+		streamReader: &streamReader[ChatCompletionStreamResponse]{
+			emptyMessagesLimit: c.config.EmptyMessagesLimit,
+			reader:             bufio.NewReader(resp.Body),
+			response:           resp,
+			errAccumulator:     newErrorAccumulator(),
+			unmarshaler:        &jsonUnmarshaler{},
+		},
 	}
 	return
 }
diff --git a/error_accumulator.go b/error_accumulator.go
new file mode 100644
index 0000000..e75086e
--- /dev/null
+++ b/error_accumulator.go
@@ -0,0 +1,51 @@
+package openai
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+)
+
+type errorAccumulator interface {
+	write(p []byte) error
+	unmarshalError() (*ErrorResponse, error)
+}
+
+type errorBuffer interface {
+	io.Writer
+	Len() int
+	Bytes() []byte
+}
+
+type errorAccumulate struct {
+	buffer      errorBuffer
+	unmarshaler unmarshaler
+}
+
+func newErrorAccumulator() errorAccumulator {
+	return &errorAccumulate{
+		buffer:      &bytes.Buffer{},
+		unmarshaler: &jsonUnmarshaler{},
+	}
+}
+
+func (e *errorAccumulate) write(p []byte) error {
+	_, err := e.buffer.Write(p)
+	if err != nil {
+		return fmt.Errorf("error accumulator write error, %w", err)
+	}
+	return nil
+}
+
+func (e *errorAccumulate) unmarshalError() (*ErrorResponse, error) {
+	var err error
+	if e.buffer.Len() > 0 {
+		var errRes ErrorResponse
+		err = e.unmarshaler.unmarshal(e.buffer.Bytes(), &errRes)
+		if err != nil {
+			return nil, err
+		}
+		return &errRes, nil
+	}
+	return nil, err
+}
diff --git a/stream.go b/stream.go
index 0eed4aa..322d27f 100644
--- a/stream.go
+++ b/stream.go
@@ -2,12 +2,8 @@ package openai
 
 import (
 	"bufio"
-	"bytes"
 	"context"
-	"encoding/json"
 	"errors"
-	"io"
-	"net/http"
 )
 
 var (
@@ -15,52 +11,7 @@ var (
 )
 
 type CompletionStream struct {
-	emptyMessagesLimit uint
-	isFinished         bool
-
-	reader   *bufio.Reader
-	response *http.Response
-}
-
-func (stream *CompletionStream) Recv() (response CompletionResponse, err error) {
-	if stream.isFinished {
-		err = io.EOF
-		return
-	}
-
-	var emptyMessagesCount uint
-
-waitForData:
-	line, err := stream.reader.ReadBytes('\n')
-	if err != nil {
-		return
-	}
-
-	var headerData = []byte("data: ")
-	line = bytes.TrimSpace(line)
-	if !bytes.HasPrefix(line, headerData) {
-		emptyMessagesCount++
-		if emptyMessagesCount > stream.emptyMessagesLimit {
-			err = ErrTooManyEmptyStreamMessages
-			return
-		}
-
-		goto waitForData
-	}
-
-	line = bytes.TrimPrefix(line, headerData)
-	if string(line) == "[DONE]" {
-		stream.isFinished = true
-		err = io.EOF
-		return
-	}
-
-	err = json.Unmarshal(line, &response)
-	return
-}
-
-func (stream *CompletionStream) Close() {
-	stream.response.Body.Close()
+	*streamReader[CompletionResponse]
 }
 
 // CreateCompletionStream — API call to create a completion w/ streaming
@@ -83,10 +34,13 @@ func (c *Client) CreateCompletionStream(
 	}
 
 	stream = &CompletionStream{
-		emptyMessagesLimit: c.config.EmptyMessagesLimit,
-
-		reader:   bufio.NewReader(resp.Body),
-		response: resp,
+		streamReader: &streamReader[CompletionResponse]{
+			emptyMessagesLimit: c.config.EmptyMessagesLimit,
+			reader:             bufio.NewReader(resp.Body),
+			response:           resp,
+			errAccumulator:     newErrorAccumulator(),
+			unmarshaler:        &jsonUnmarshaler{},
+		},
 	}
 	return
 }
diff --git a/stream_reader.go b/stream_reader.go
new file mode 100644
index 0000000..07500a5
--- /dev/null
+++ b/stream_reader.go
@@ -0,0 +1,71 @@
+package openai
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+type streamable interface {
+	ChatCompletionStreamResponse | CompletionResponse
+}
+
+type streamReader[T streamable] struct {
+	emptyMessagesLimit uint
+	isFinished         bool
+
+	reader         *bufio.Reader
+	response       *http.Response
+	errAccumulator errorAccumulator
+	unmarshaler    unmarshaler
+}
+
+func (stream *streamReader[T]) Recv() (response T, err error) {
+	if stream.isFinished {
+		err = io.EOF
+		return
+	}
+
+	var emptyMessagesCount uint
+
+waitForData:
+	line, err := stream.reader.ReadBytes('\n')
+	if err != nil {
+		if errRes, _ := stream.errAccumulator.unmarshalError(); errRes != nil {
+			err = fmt.Errorf("error, %w", errRes.Error)
+		}
+		return
+	}
+
+	var headerData = []byte("data: ")
+	line = bytes.TrimSpace(line)
+	if !bytes.HasPrefix(line, headerData) {
+		if writeErr := stream.errAccumulator.write(line); writeErr != nil {
+			err = writeErr
+			return
+		}
+		emptyMessagesCount++
+		if emptyMessagesCount > stream.emptyMessagesLimit {
+			err = ErrTooManyEmptyStreamMessages
+			return
+		}
+
+		goto waitForData
+	}
+
+	line = bytes.TrimPrefix(line, headerData)
+	if string(line) == "[DONE]" {
+		stream.isFinished = true
+		err = io.EOF
+		return
+	}
+
+	err = stream.unmarshaler.unmarshal(line, &response)
+	return
+}
+
+func (stream *streamReader[T]) Close() {
+	stream.response.Body.Close()
+}
diff --git a/unmarshaler.go b/unmarshaler.go
new file mode 100644
index 0000000..05218f7
--- /dev/null
+++ b/unmarshaler.go
@@ -0,0 +1,15 @@
+package openai
+
+import (
+	"encoding/json"
+)
+
+type unmarshaler interface {
+	unmarshal(data []byte, v any) error
+}
+
+type jsonUnmarshaler struct{}
+
+func (jm *jsonUnmarshaler) unmarshal(data []byte, v any) error {
+	return json.Unmarshal(data, v)
+}


Test patch:
diff --git a/chat_stream_test.go b/chat_stream_test.go
index e3da2da..de604fa 100644
--- a/chat_stream_test.go
+++ b/chat_stream_test.go
@@ -123,6 +123,73 @@ func TestCreateChatCompletionStream(t *testing.T) {
 	}
 }
 
+func TestCreateChatCompletionStreamError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/event-stream")
+
+		// Send test responses
+		dataBytes := []byte{}
+		dataStr := []string{
+			`{`,
+			`"error": {`,
+			`"message": "Incorrect API key provided: sk-***************************************",`,
+			`"type": "invalid_request_error",`,
+			`"param": null,`,
+			`"code": "invalid_api_key"`,
+			`}`,
+			`}`,
+		}
+		for _, str := range dataStr {
+			dataBytes = append(dataBytes, []byte(str+"\n")...)
+		}
+
+		_, err := w.Write(dataBytes)
+		if err != nil {
+			t.Errorf("Write error: %s", err)
+		}
+	}))
+	defer server.Close()
+
+	// Client portion of the test
+	config := DefaultConfig(test.GetTestToken())
+	config.BaseURL = server.URL + "/v1"
+	config.HTTPClient.Transport = &tokenRoundTripper{
+		test.GetTestToken(),
+		http.DefaultTransport,
+	}
+
+	client := NewClientWithConfig(config)
+	ctx := context.Background()
+
+	request := ChatCompletionRequest{
+		MaxTokens: 5,
+		Model:     GPT3Dot5Turbo,
+		Messages: []ChatCompletionMessage{
+			{
+				Role:    ChatMessageRoleUser,
+				Content: "Hello!",
+			},
+		},
+		Stream: true,
+	}
+
+	stream, err := client.CreateChatCompletionStream(ctx, request)
+	if err != nil {
+		t.Errorf("CreateCompletionStream returned error: %v", err)
+	}
+	defer stream.Close()
+
+	_, streamErr := stream.Recv()
+	if streamErr == nil {
+		t.Errorf("stream.Recv() did not return error")
+	}
+	var apiErr *APIError
+	if !errors.As(streamErr, &apiErr) {
+		t.Errorf("stream.Recv() did not return APIError")
+	}
+	t.Logf("%+v\n", apiErr)
+}
+
 // Helper funcs.
 func compareChatResponses(r1, r2 ChatCompletionStreamResponse) bool {
 	if r1.ID != r2.ID || r1.Object != r2.Object || r1.Created != r2.Created || r1.Model != r2.Model {
diff --git a/error_accumulator_test.go b/error_accumulator_test.go
new file mode 100644
index 0000000..d4008c0
--- /dev/null
+++ b/error_accumulator_test.go
@@ -0,0 +1,90 @@
+package openai //nolint:testpackage // testing private field
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/sashabaranov/go-openai/internal/test"
+)
+
+var (
+	errTestUnmarshalerFailed           = errors.New("test unmarshaler failed")
+	errTestErrorAccumulatorWriteFailed = errors.New("test error accumulator failed")
+)
+
+type (
+	failingUnMarshaller struct{}
+	failingErrorBuffer  struct{}
+)
+
+func (b *failingErrorBuffer) Write(_ []byte) (n int, err error) {
+	return 0, errTestErrorAccumulatorWriteFailed
+}
+
+func (b *failingErrorBuffer) Len() int {
+	return 0
+}
+
+func (b *failingErrorBuffer) Bytes() []byte {
+	return []byte{}
+}
+
+func (*failingUnMarshaller) unmarshal(_ []byte, _ any) error {
+	return errTestUnmarshalerFailed
+}
+
+func TestErrorAccumulatorReturnsUnmarshalerErrors(t *testing.T) {
+	accumulator := &errorAccumulate{
+		buffer:      &bytes.Buffer{},
+		unmarshaler: &failingUnMarshaller{},
+	}
+
+	err := accumulator.write([]byte("{"))
+	if err != nil {
+		t.Fatalf("%+v", err)
+	}
+	_, err = accumulator.unmarshalError()
+	if !errors.Is(err, errTestUnmarshalerFailed) {
+		t.Fatalf("Did not return error when unmarshaler failed: %v", err)
+	}
+}
+
+func TestErrorByteWriteErrors(t *testing.T) {
+	accumulator := &errorAccumulate{
+		buffer:      &failingErrorBuffer{},
+		unmarshaler: &jsonUnmarshaler{},
+	}
+	err := accumulator.write([]byte("{"))
+	if !errors.Is(err, errTestErrorAccumulatorWriteFailed) {
+		t.Fatalf("Did not return error when write failed: %v", err)
+	}
+}
+
+func TestErrorAccumulatorWriteErrors(t *testing.T) {
+	var err error
+	ts := test.NewTestServer().OpenAITestServer()
+	ts.Start()
+	defer ts.Close()
+
+	config := DefaultConfig(test.GetTestToken())
+	config.BaseURL = ts.URL + "/v1"
+	client := NewClientWithConfig(config)
+
+	ctx := context.Background()
+
+	stream, err := client.CreateChatCompletionStream(ctx, ChatCompletionRequest{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	stream.errAccumulator = &errorAccumulate{
+		buffer:      &failingErrorBuffer{},
+		unmarshaler: &jsonUnmarshaler{},
+	}
+
+	_, err = stream.Recv()
+	if !errors.Is(err, errTestErrorAccumulatorWriteFailed) {
+		t.Fatalf("Did not return error when write failed: %v", err)
+	}
+}
diff --git a/stream_test.go b/stream_test.go
index 8f89e6b..ce560c6 100644
--- a/stream_test.go
+++ b/stream_test.go
@@ -100,6 +100,68 @@ func TestCreateCompletionStream(t *testing.T) {
 	}
 }
 
+func TestCreateCompletionStreamError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/event-stream")
+
+		// Send test responses
+		dataBytes := []byte{}
+		dataStr := []string{
+			`{`,
+			`"error": {`,
+			`"message": "Incorrect API key provided: sk-***************************************",`,
+			`"type": "invalid_request_error",`,
+			`"param": null,`,
+			`"code": "invalid_api_key"`,
+			`}`,
+			`}`,
+		}
+		for _, str := range dataStr {
+			dataBytes = append(dataBytes, []byte(str+"\n")...)
+		}
+
+		_, err := w.Write(dataBytes)
+		if err != nil {
+			t.Errorf("Write error: %s", err)
+		}
+	}))
+	defer server.Close()
+
+	// Client portion of the test
+	config := DefaultConfig(test.GetTestToken())
+	config.BaseURL = server.URL + "/v1"
+	config.HTTPClient.Transport = &tokenRoundTripper{
+		test.GetTestToken(),
+		http.DefaultTransport,
+	}
+
+	client := NewClientWithConfig(config)
+	ctx := context.Background()
+
+	request := CompletionRequest{
+		MaxTokens: 5,
+		Model:     GPT3Dot5Turbo,
+		Prompt:    "Hello!",
+		Stream:    true,
+	}
+
+	stream, err := client.CreateCompletionStream(ctx, request)
+	if err != nil {
+		t.Errorf("CreateCompletionStream returned error: %v", err)
+	}
+	defer stream.Close()
+
+	_, streamErr := stream.Recv()
+	if streamErr == nil {
+		t.Errorf("stream.Recv() did not return error")
+	}
+	var apiErr *APIError
+	if !errors.As(streamErr, &apiErr) {
+		t.Errorf("stream.Recv() did not return APIError")
+	}
+	t.Logf("%+v\n", apiErr)
+}
+
 // A "tokenRoundTripper" is a struct that implements the RoundTripper
 // interface, specifically to handle the authentication token by adding a token
 // to the request header. We need this because the API requires that each