Resolve sashabaranov#487: Enhance tests and fix linting issues

- Add randomized fields to Engine structs in tests
- Implement cryptographically secure random utility functions
- Address golangci-lint warnings

engines_test.go

@@ -8,15 +8,27 @@ import (
 	"testing"
 
 	. "github.com/sashabaranov/go-openai"
+	"github.com/sashabaranov/go-openai/internal/test"
 	"github.com/sashabaranov/go-openai/internal/test/checks"
 )
 
+// Helper function to test the ListEngines endpoint.
+func RandomEngine() Engine {
+	return Engine{
+		ID:     test.RandomString(),
+		Object: test.RandomString(),
+		Owner:  test.RandomString(),
+		Ready:  test.RandomBool(),
+	}
+}
+
 // TestGetEngine Tests the retrieve engine endpoint of the API using the mocked server.
 func TestGetEngine(t *testing.T) {
 	client, server, teardown := setupOpenAITestServer()
 	defer teardown()
 	server.RegisterHandler("/v1/engines/text-davinci-003", func(w http.ResponseWriter, r *http.Request) {
-		resBytes, _ := json.Marshal(Engine{})
+		engine := RandomEngine()
+		resBytes, _ := json.Marshal(engine)
 		fmt.Fprintln(w, string(resBytes))
 	})
 	_, err := client.GetEngine(context.Background(), "text-davinci-003")
@@ -28,7 +40,11 @@ func TestListEngines(t *testing.T) {
 	client, server, teardown := setupOpenAITestServer()
 	defer teardown()
 	server.RegisterHandler("/v1/engines", func(w http.ResponseWriter, r *http.Request) {
-		resBytes, _ := json.Marshal(EnginesList{})
+		engines := make([]Engine, 5)
+		for i := range engines {
+			engines[i] = RandomEngine()
+		}
+		resBytes, _ := json.Marshal(EnginesList{Engines: engines})
 		fmt.Fprintln(w, string(resBytes))
 	})
 	_, err := client.ListEngines(context.Background())

internal/test/random.go

@@ -0,0 +1,35 @@
+package test
+
+import (
+	"crypto/rand"
+	"math/big"
+)
+
+var (
+	strLen = 10
+	//nolint:gomnd // this avoids the golangci-lint "magic number" warning
+	n = big.NewInt(2)
+)
+
+// RandomString generates a cryptographically secure random string of a fixed
+// length. The string is composed of alphanumeric characters and is generated
+// using the crypto/rand library. The length of the string is determined by the
+// constant strLen.
+func RandomString() string {
+	var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	s := make([]rune, strLen)
+	max := big.NewInt(int64(len(letters)))
+	for i := range s {
+		randomInt, _ := rand.Int(rand.Reader, max)
+		s[i] = letters[randomInt.Int64()]
+	}
+	return string(s)
+}
+
+// RandomBool generates a cryptographically secure random boolean value. It
+// uses the crypto/rand library to generate a random integer (either 0 or 1),
+// and returns true if the integer is 1, and false otherwise.
+func RandomBool() bool {
+	randomInt, _ := rand.Int(rand.Reader, n)
+	return randomInt.Int64() == 1
+}