add more tests (#140)

* test models endpoint

* simplify

* add fine tune tests

models_test.go

@@ -0,0 +1,39 @@
+package openai_test
+
+import (
+	. "github.com/sashabaranov/go-openai"
+	"github.com/sashabaranov/go-openai/internal/test"
+
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"testing"
+)
+
+// TestListModels Tests the models endpoint of the API using the mocked server.
+func TestListModels(t *testing.T) {
+	server := test.NewTestServer()
+	server.RegisterHandler("/v1/models", handleModelsEndpoint)
+	// create the test server
+	var err error
+	ts := server.OpenAITestServer()
+	ts.Start()
+	defer ts.Close()
+
+	config := DefaultConfig(test.GetTestToken())
+	config.BaseURL = ts.URL + "/v1"
+	client := NewClientWithConfig(config)
+	ctx := context.Background()
+
+	_, err = client.ListModels(ctx)
+	if err != nil {
+		t.Fatalf("ListModels error: %v", err)
+	}
+}
+
+// handleModelsEndpoint Handles the models endpoint by the test server.
+func handleModelsEndpoint(w http.ResponseWriter, r *http.Request) {
+	resBytes, _ := json.Marshal(ModelsList{})
+	fmt.Fprintln(w, string(resBytes))
+}