feat: add -system flag to ls tests for optional system ls usage

This commit introduces a new command-line flag, -system, to the ls test suite, allowing users to opt for the system 'ls' command instead of the custom implementation. The tests are updated to skip execution when the system flag is used, ensuring compatibility and flexibility in testing scenarios.

internal/custom_executable/ls/ls_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
 	"os/exec"
@@ -11,6 +12,10 @@ import (
 	"testing"
 )
 
+// Pass the -system flag to use system ls instead of custom implementation
+// go test ./... -system
+var useSystemLs = flag.Bool("system", false, "Use system ls instead of custom implementation")
+
 // testFile represents a file or directory to be created for testing
 type testFile struct {
 	name    string
@@ -37,6 +42,10 @@ func createTestFiles(t *testing.T, dir string, files []testFile) {
 }
 
 func getLsExecutable(t *testing.T) string {
+	if *useSystemLs {
+		return "ls"
+	}
+
 	switch runtime.GOOS {
 	case "darwin":
 		switch runtime.GOARCH {
@@ -301,6 +310,9 @@ func TestLsWithDashOneFlag(t *testing.T) {
 }
 
 func TestLsWithUnsupportedFlag(t *testing.T) {
+	if *useSystemLs {
+		t.Skip("Skipping test because system ls is used")
+	}
 	// Create a temporary directory for testing
 	tmpDir, err := os.MkdirTemp("", "ls-test-*")
 	if err != nil {
@@ -323,6 +335,10 @@ func TestLsWithUnsupportedFlag(t *testing.T) {
 }
 
 func TestLsWithUnsupportedFlag2(t *testing.T) {
+	if *useSystemLs {
+		t.Skip("Skipping test because system ls is used")
+	}
+
 	// Run ls and get output
 	output, err := runLs(t, "-n")
 	if err == nil {
@@ -339,6 +355,10 @@ func TestLsWithUnsupportedFlag2(t *testing.T) {
 }
 
 func TestLsWithUnsupportedFlag3(t *testing.T) {
+	if *useSystemLs {
+		t.Skip("Skipping test because system ls is used")
+	}
+
 	// Run ls and get output
 	output, err := runLs(t, "-l -a")
 	if err == nil {