feat: Add testTxEmpty function to internal package

This commit adds the testTxEmpty function to the internal package. The function tests an empty transaction by running a Redis executable and executing various test cases. It includes assertions for error handling and ensures that the EXEC command without MULTI returns an error.

internal/test_txn_empty.go

@@ -0,0 +1,44 @@
+package internal
+
+import (
+	"github.com/codecrafters-io/redis-tester/internal/redis_executable"
+	resp_value "github.com/codecrafters-io/redis-tester/internal/resp/value"
+	"github.com/codecrafters-io/redis-tester/internal/resp_assertions"
+
+	"github.com/codecrafters-io/redis-tester/internal/instrumented_resp_connection"
+	"github.com/codecrafters-io/redis-tester/internal/test_cases"
+	"github.com/codecrafters-io/tester-utils/test_case_harness"
+)
+
+func testTxEmpty(stageHarness *test_case_harness.TestCaseHarness) error {
+	b := redis_executable.NewRedisExecutable(stageHarness)
+	if err := b.Run(); err != nil {
+		return err
+	}
+
+	logger := stageHarness.Logger
+
+	client, err := instrumented_resp_connection.NewFromAddr(stageHarness, "localhost:6379", "client1")
+	if err != nil {
+		logFriendlyError(logger, err)
+		return err
+	}
+	defer client.Close()
+
+	emptyTransactionTestCase := test_cases.TransactionTestCase{
+		CommandQueue: [][]string{},
+		ResultArray:  []resp_value.Value{},
+	}
+
+	if err := emptyTransactionTestCase.RunAll(client, logger); err != nil {
+		return err
+	}
+
+	bareExecCommandTestCase := test_cases.SendCommandTestCase{
+		Command:   "EXEC",
+		Args:      []string{},
+		Assertion: resp_assertions.NewErrorAssertion("ERR EXEC without MULTI"),
+	}
+
+	return bareExecCommandTestCase.Run(client, logger)
+}