feat: support direct bytes for file upload (sashabaranov#568)

* feat: support direct bytes for file upload

* add test for errors

* add coverage

client_test.go

@@ -247,6 +247,9 @@ func TestClientReturnsRequestBuilderErrors(t *testing.T) {
 		{"CreateImage", func() (any, error) {
 			return client.CreateImage(ctx, ImageRequest{})
 		}},
+		{"CreateFileBytes", func() (any, error) {
+			return client.CreateFileBytes(ctx, FileBytesRequest{})
+		}},
 		{"DeleteFile", func() (any, error) {
 			return nil, client.DeleteFile(ctx, "")
 		}},

files.go

@@ -15,6 +15,24 @@ type FileRequest struct {
 	Purpose  string `json:"purpose"`
 }
 
+// PurposeType represents the purpose of the file when uploading.
+type PurposeType string
+
+const (
+	PurposeFineTune   PurposeType = "fine-tune"
+	PurposeAssistants PurposeType = "assistants"
+)
+
+// FileBytesRequest represents a file upload request.
+type FileBytesRequest struct {
+	// the name of the uploaded file in OpenAI
+	Name string
+	// the bytes of the file
+	Bytes []byte
+	// the purpose of the file
+	Purpose PurposeType
+}
+
 // File struct represents an OpenAPI file.
 type File struct {
 	Bytes         int    `json:"bytes"`
@@ -36,6 +54,37 @@ type FilesList struct {
 	httpHeader
 }
 
+// CreateFileBytes uploads bytes directly to OpenAI without requiring a local file.
+func (c *Client) CreateFileBytes(ctx context.Context, request FileBytesRequest) (file File, err error) {
+	var b bytes.Buffer
+	reader := bytes.NewReader(request.Bytes)
+	builder := c.createFormBuilder(&b)
+
+	err = builder.WriteField("purpose", string(request.Purpose))
+	if err != nil {
+		return
+	}
+
+	err = builder.CreateFormFileReader("file", reader, request.Name)
+	if err != nil {
+		return
+	}
+
+	err = builder.Close()
+	if err != nil {
+		return
+	}
+
+	req, err := c.newRequest(ctx, http.MethodPost, c.fullURL("/files"),
+		withBody(&b), withContentType(builder.FormDataContentType()))
+	if err != nil {
+		return
+	}
+
+	err = c.sendRequest(req, &file)
+	return
+}
+
 // CreateFile uploads a jsonl file to GPT3
 // FilePath must be a local file path.
 func (c *Client) CreateFile(ctx context.Context, request FileRequest) (file File, err error) {

files_api_test.go

@@ -16,6 +16,19 @@ import (
 	"github.com/sashabaranov/go-openai/internal/test/checks"
 )
 
+func TestFileBytesUpload(t *testing.T) {
+	client, server, teardown := setupOpenAITestServer()
+	defer teardown()
+	server.RegisterHandler("/v1/files", handleCreateFile)
+	req := openai.FileBytesRequest{
+		Name:    "foo",
+		Bytes:   []byte("foo"),
+		Purpose: openai.PurposeFineTune,
+	}
+	_, err := client.CreateFileBytes(context.Background(), req)
+	checks.NoError(t, err, "CreateFile error")
+}
+
 func TestFileUpload(t *testing.T) {
 	client, server, teardown := setupOpenAITestServer()
 	defer teardown()

files_test.go

@@ -11,6 +11,53 @@ import (
 	"github.com/sashabaranov/go-openai/internal/test/checks"
 )
 
+func TestFileBytesUploadWithFailingFormBuilder(t *testing.T) {
+	config := DefaultConfig("")
+	config.BaseURL = ""
+	client := NewClientWithConfig(config)
+	mockBuilder := &mockFormBuilder{}
+	client.createFormBuilder = func(io.Writer) utils.FormBuilder {
+		return mockBuilder
+	}
+
+	ctx := context.Background()
+	req := FileBytesRequest{
+		Name:    "foo",
+		Bytes:   []byte("foo"),
+		Purpose: PurposeAssistants,
+	}
+
+	mockError := fmt.Errorf("mockWriteField error")
+	mockBuilder.mockWriteField = func(string, string) error {
+		return mockError
+	}
+	_, err := client.CreateFileBytes(ctx, req)
+	checks.ErrorIs(t, err, mockError, "CreateFile should return error if form builder fails")
+
+	mockError = fmt.Errorf("mockCreateFormFile error")
+	mockBuilder.mockWriteField = func(string, string) error {
+		return nil
+	}
+	mockBuilder.mockCreateFormFileReader = func(string, io.Reader, string) error {
+		return mockError
+	}
+	_, err = client.CreateFileBytes(ctx, req)
+	checks.ErrorIs(t, err, mockError, "CreateFile should return error if form builder fails")
+
+	mockError = fmt.Errorf("mockClose error")
+	mockBuilder.mockWriteField = func(string, string) error {
+		return nil
+	}
+	mockBuilder.mockCreateFormFileReader = func(string, io.Reader, string) error {
+		return nil
+	}
+	mockBuilder.mockClose = func() error {
+		return mockError
+	}
+	_, err = client.CreateFileBytes(ctx, req)
+	checks.ErrorIs(t, err, mockError, "CreateFile should return error if form builder fails")
+}
+
 func TestFileUploadWithFailingFormBuilder(t *testing.T) {
 	config := DefaultConfig("")
 	config.BaseURL = ""
@@ -55,6 +102,9 @@ func TestFileUploadWithFailingFormBuilder(t *testing.T) {
 		return mockError
 	}
 	_, err = client.CreateFile(ctx, req)
+	if err == nil {
+		t.Fatal("CreateFile should return error if form builder fails")
+	}
 	checks.ErrorIs(t, err, mockError, "CreateFile should return error if form builder fails")
 }