add testable json marshaller (#161)

api.go

@@ -11,17 +11,22 @@ import (
 // Client is OpenAI GPT-3 API client.
 type Client struct {
 	config ClientConfig
+
+	marshaller marshaller
 }
 
 // NewClient creates new OpenAI API client.
 func NewClient(authToken string) *Client {
 	config := DefaultConfig(authToken)
-	return &Client{config}
+	return NewClientWithConfig(config)
 }
 
 // NewClientWithConfig creates new OpenAI API client for specified config.
 func NewClientWithConfig(config ClientConfig) *Client {
-	return &Client{config}
+	return &Client{
+		config:     config,
+		marshaller: &jsonMarshaller{},
+	}
 }
 
 // NewOrgClient creates new OpenAI API client for specified Organization ID.
@@ -30,7 +35,7 @@ func NewClientWithConfig(config ClientConfig) *Client {
 func NewOrgClient(authToken, org string) *Client {
 	config := DefaultConfig(authToken)
 	config.OrgID = org
-	return &Client{config}
+	return NewClientWithConfig(config)
 }
 
 func (c *Client) sendRequest(req *http.Request, v interface{}) error {
@@ -90,7 +95,7 @@ func (c *Client) newStreamRequest(
 	var reqBody []byte
 	if body != nil {
 		var err error
-		reqBody, err = json.Marshal(body)
+		reqBody, err = c.marshaller.marshal(body)
 		if err != nil {
 			return nil, err
 		}

chat.go

@@ -3,7 +3,6 @@ package openai
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"errors"
 	"net/http"
 )
@@ -74,7 +73,7 @@ func (c *Client) CreateChatCompletion(
 	}
 
 	var reqBytes []byte
-	reqBytes, err = json.Marshal(request)
+	reqBytes, err = c.marshaller.marshal(request)
 	if err != nil {
 		return
 	}

completion.go

@@ -3,7 +3,6 @@ package openai
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"errors"
 	"net/http"
 )
@@ -107,7 +106,7 @@ func (c *Client) CreateCompletion(
 	}
 
 	var reqBytes []byte
-	reqBytes, err = json.Marshal(request)
+	reqBytes, err = c.marshaller.marshal(request)
 	if err != nil {
 		return
 	}

edits.go

@@ -3,7 +3,6 @@ package openai
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"net/http"
 )
 
@@ -34,7 +33,7 @@ type EditsResponse struct {
 // Perform an API call to the Edits endpoint.
 func (c *Client) Edits(ctx context.Context, request EditsRequest) (response EditsResponse, err error) {
 	var reqBytes []byte
-	reqBytes, err = json.Marshal(request)
+	reqBytes, err = c.marshaller.marshal(request)
 	if err != nil {
 		return
 	}

embeddings.go

@@ -3,7 +3,6 @@ package openai
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"net/http"
 )
 
@@ -135,7 +134,7 @@ type EmbeddingRequest struct {
 // https://beta.openai.com/docs/api-reference/embeddings/create
 func (c *Client) CreateEmbeddings(ctx context.Context, request EmbeddingRequest) (resp EmbeddingResponse, err error) {
 	var reqBytes []byte
-	reqBytes, err = json.Marshal(request)
+	reqBytes, err = c.marshaller.marshal(request)
 	if err != nil {
 		return
 	}

fine_tunes.go

@@ -3,7 +3,6 @@ package openai
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"net/http"
 )
@@ -70,7 +69,7 @@ type FineTuneDeleteResponse struct {
 
 func (c *Client) CreateFineTune(ctx context.Context, request FineTuneRequest) (response FineTune, err error) {
 	var reqBytes []byte
-	reqBytes, err = json.Marshal(request)
+	reqBytes, err = c.marshaller.marshal(request)
 	if err != nil {
 		return
 	}

image.go

@@ -3,7 +3,6 @@ package openai
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"io"
 	"mime/multipart"
 	"net/http"
@@ -47,7 +46,7 @@ type ImageResponseDataInner struct {
 // CreateImage - API call to create an image. This is the main endpoint of the DALL-E API.
 func (c *Client) CreateImage(ctx context.Context, request ImageRequest) (response ImageResponse, err error) {
 	var reqBytes []byte
-	reqBytes, err = json.Marshal(request)
+	reqBytes, err = c.marshaller.marshal(request)
 	if err != nil {
 		return
 	}

marshaller.go

@@ -0,0 +1,15 @@
+package openai
+
+import (
+	"encoding/json"
+)
+
+type marshaller interface {
+	marshal(value any) ([]byte, error)
+}
+
+type jsonMarshaller struct{}
+
+func (jm *jsonMarshaller) marshal(value any) ([]byte, error) {
+	return json.Marshal(value)
+}

marshaller_test.go

@@ -0,0 +1,71 @@
+package openai //nolint:testpackage // testing private field
+
+import (
+	"github.com/sashabaranov/go-openai/internal/test"
+
+	"context"
+	"errors"
+	"testing"
+)
+
+type failingMarshaller struct{}
+
+var errTestMarshallerFailed = errors.New("test marshaller failed")
+
+func (jm *failingMarshaller) marshal(value any) ([]byte, error) {
+	return []byte{}, errTestMarshallerFailed
+}
+
+func TestClientReturnMarshallerErrors(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)
+	client.marshaller = &failingMarshaller{}
+
+	ctx := context.Background()
+
+	_, err = client.CreateCompletion(ctx, CompletionRequest{})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+
+	_, err = client.CreateChatCompletion(ctx, ChatCompletionRequest{Model: GPT3Dot5Turbo})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+
+	_, err = client.CreateChatCompletionStream(ctx, ChatCompletionRequest{})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+
+	_, err = client.CreateFineTune(ctx, FineTuneRequest{})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+
+	_, err = client.Moderations(ctx, ModerationRequest{})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+
+	_, err = client.Edits(ctx, EditsRequest{})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+
+	_, err = client.CreateEmbeddings(ctx, EmbeddingRequest{})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+
+	_, err = client.CreateImage(ctx, ImageRequest{})
+	if !errors.Is(err, errTestMarshallerFailed) {
+		t.Fatalf("Did not return error when marshaller failed: %v", err)
+	}
+}

moderation.go

@@ -3,7 +3,6 @@ package openai
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"net/http"
 )
 
@@ -53,7 +52,7 @@ type ModerationResponse struct {
 // Input can be an array or slice but a string will reduce the complexity.
 func (c *Client) Moderations(ctx context.Context, request ModerationRequest) (response ModerationResponse, err error) {
 	var reqBytes []byte
-	reqBytes, err = json.Marshal(request)
+	reqBytes, err = c.marshaller.marshal(request)
 	if err != nil {
 		return
 	}