add core copyfile func

core/os.go

@@ -1,7 +1,9 @@
 package core
 
 import (
+	"fmt"
 	"github.com/mitchellh/go-homedir"
+	"io"
 	"os"
 	"strconv"
 	"strings"
@@ -67,3 +69,39 @@
 
 	return strings.HasSuffix(os.Args[0], ".test")
 }
+
+// CopyFile copies a file from src to dest and preserves its permissions.
+func CopyFile(src, dest string) error {
+	// Open source file for reading
+	//nolint: gosec
+	srcFile, err := os.Open(src)
+	if err != nil {
+		return fmt.Errorf("failed to open source file: %w", err)
+	}
+	defer func() {
+		_ = srcFile.Close()
+	}()
+
+	// Obtain stat information from source
+	srcInfo, err := srcFile.Stat()
+	if err != nil {
+		return fmt.Errorf("failed to stat source file: %w", err)
+	}
+
+	// Create destination file with the source file permissions
+	//nolint: gosec
+	destFile, err := os.OpenFile(dest, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, srcInfo.Mode())
+	if err != nil {
+		return fmt.Errorf("failed to open destination file: %w", err)
+	}
+	defer func() {
+		_ = destFile.Close()
+	}()
+
+	// Copy data from source to destination
+	if _, err := io.Copy(destFile, srcFile); err != nil {
+		return fmt.Errorf("failed to copy data from source to destination: %w", err)
+	}
+
+	return nil
+}

core/os_test.go

@@ -1,6 +1,8 @@
 package core_test
 
 import (
+	"bytes"
+	"github.com/Flaque/filet"
 	"github.com/brianvoe/gofakeit/v6"
 	. "github.com/stretchr/testify/assert"
 	common "github.com/synapsecns/sanguine/core"
@@ -110,3 +112,42 @@ func TestGetEnvBool(t *testing.T) {
 		})
 	}
 }
+
+func TestCopyFile(t *testing.T) {
+	// Prepare test files
+	content := []byte("This is a test content.")
+	src := filet.TmpFile(t, "", string(content))
+
+	dest := filet.TmpFile(t, "", string(content))
+	_ = dest.Close()
+
+	// Copy file
+	if err := common.CopyFile(src.Name(), dest.Name()); err != nil {
+		t.Errorf("CopyFile() error: %v", err)
+	}
+
+	// Check if file is copied correctly
+	destContent, err := os.ReadFile(dest.Name())
+	if err != nil {
+		t.Fatalf("Failed to read dest file: %v", err)
+	}
+
+	if !bytes.Equal(content, destContent) {
+		t.Errorf("Content mismatch: expected %s, got %s", content, destContent)
+	}
+
+	// Check if permissions are the same
+	srcInfo, err := os.Stat(src.Name())
+	if err != nil {
+		t.Fatalf("Failed to stat src file: %v", err)
+	}
+
+	destInfo, err := os.Stat(dest.Name())
+	if err != nil {
+		t.Fatalf("Failed to stat dest file: %v", err)
+	}
+
+	if srcInfo.Mode() != destInfo.Mode() {
+		t.Errorf("Permission mismatch: expected %v, got %v", srcInfo.Mode(), destInfo.Mode())
+	}
+}