Create RandomInt Function

- Memory efficient solution for RandomInt func
- Improve error handling by logging them vice returning the type
- Use RandomInt() instead

Resolves: sashabaranov#487

engines_test.go

@@ -40,7 +40,7 @@ func TestListEngines(t *testing.T) {
 	client, server, teardown := setupOpenAITestServer()
 	defer teardown()
 	server.RegisterHandler("/v1/engines", func(w http.ResponseWriter, r *http.Request) {
-		engines := make([]Engine, 5)
+		engines := make([]Engine, test.RandomInt(5))
 		for i := range engines {
 			engines[i] = RandomEngine()
 		}

internal/test/random.go

@@ -2,11 +2,13 @@ package test
 
 import (
 	"crypto/rand"
+	"log"
 	"strings"
 )
 
 const letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 const strLen = 10
+const bitLen = 0xFF
 
 // See StackOverflow answer:
 // https://stackoverflow.com/questions/22892120/how-to-generate-a-random-string-of-a-fixed-length-in-go
@@ -20,7 +22,7 @@ func RandomString() string {
 		randomByte := make([]byte, 1)
 		_, err := rand.Read(randomByte)
 		if err != nil {
-			return ""
+			log.Fatalf("Error generating random string: %v", err)
 		}
 		randomIndex := randomByte[0] % byte(len(letters))
 		sb.WriteByte(letters[randomIndex])
@@ -29,6 +31,21 @@ func RandomString() string {
 	return sb.String()
 }
 
+// RandomInt generates a random integer between 0 (inclusive) and 'max'
+// (exclusive). We uses the crypto/rand library for generating random
+// bytes. It then performs a bitwise AND operation with 0xFF to keep only the
+// least significant 8 bits, effectively converting the byte to an integer. The
+// resulting integer is then modulo'd with 'max'.
+func RandomInt(max int) int {
+	var b [1]byte
+	_, err := rand.Read(b[:])
+	if err != nil {
+		log.Fatalf("Error generating random int: %v", err)
+	}
+	n := int(b[0]&bitLen) % max
+	return n
+}
+
 // RandomBool generates a cryptographically secure random boolean value.
 // It reads a single byte from the crypto/rand library and uses its least
 // significant bit to determine the boolean value. The function returns
@@ -37,7 +54,7 @@ func RandomBool() bool {
 	var b [1]byte
 	_, err := rand.Read(b[:])
 	if err != nil {
-		return false
+		log.Fatalf("Error generating random bool: %v", err)
 	}
 	return b[0]&1 == 1
 }