From 22188f777e52cf58e5c05761f44328457420402c Mon Sep 17 00:00:00 2001
From: Tim Ramlot <42113979+inteon@users.noreply.github.com>
Date: Mon, 12 Jan 2026 15:42:55 +0100
Subject: [PATCH] Adds String functions to filesystem implementations.

In error messages, filesystems are often printed (eg. 'fmt.Errorf("could not open repositories file in %s", a.fs)'). Without String function, this resulted in unreadable error messages.

Signed-off-by: Tim Ramlot <42113979+inteon@users.noreply.github.com>
---
 pkg/apk/fs/memfs.go  | 4 ++++
 pkg/apk/fs/rwosfs.go | 4 ++++
 pkg/apk/fs/sub.go    | 5 +++++
 pkg/tarfs/fs.go      | 4 ++++
 4 files changed, 17 insertions(+)

diff --git a/pkg/apk/fs/memfs.go b/pkg/apk/fs/memfs.go
index e542636f5..a580eb64f 100644
--- a/pkg/apk/fs/memfs.go
+++ b/pkg/apk/fs/memfs.go
@@ -54,6 +54,10 @@ func NewMemFS() FullFS {
 	}
 }
 
+func (m *memFS) String() string {
+	return "memfs"
+}
+
 // getNode returns the node for the given path. If the path is not found, it
 // returns an error.
 func (m *memFS) getNode(path string) (*node, error) {
diff --git a/pkg/apk/fs/rwosfs.go b/pkg/apk/fs/rwosfs.go
index 6b0e797a4..a9ed92929 100644
--- a/pkg/apk/fs/rwosfs.go
+++ b/pkg/apk/fs/rwosfs.go
@@ -207,6 +207,10 @@ type dirFS struct {
 	caseMapMutex sync.Mutex
 }
 
+func (f *dirFS) String() string {
+	return fmt.Sprintf("dirfs:%s", f.base)
+}
+
 func (f *dirFS) Readlink(name string) (string, error) {
 	// The underlying filesystem might not support symlinks, and it might be case-insensitive, so just
 	// use the one in memory.
diff --git a/pkg/apk/fs/sub.go b/pkg/apk/fs/sub.go
index 7a1485268..4ff3e80dc 100644
--- a/pkg/apk/fs/sub.go
+++ b/pkg/apk/fs/sub.go
@@ -2,6 +2,7 @@ package fs
 
 import (
 	"errors"
+	"fmt"
 	"io/fs"
 	"path/filepath"
 	"time"
@@ -12,6 +13,10 @@ type SubFS struct {
 	Root string
 }
 
+func (s *SubFS) String() string {
+	return fmt.Sprintf("%s:%s", s.FS, s.Root)
+}
+
 func (s *SubFS) Open(path string) (fs.File, error) {
 	if !fs.ValidPath(path) {
 		return nil, &fs.PathError{Op: "open", Path: path, Err: fs.ErrInvalid}
diff --git a/pkg/tarfs/fs.go b/pkg/tarfs/fs.go
index c37756b54..2c6fb8f2e 100644
--- a/pkg/tarfs/fs.go
+++ b/pkg/tarfs/fs.go
@@ -104,6 +104,10 @@ func checksumFromHeader(header *tar.Header) ([]byte, error) {
 	return checksum, nil
 }
 
+func (m *memFS) String() string {
+	return "tarfs"
+}
+
 func (m *memFS) WriteHeader(hdr tar.Header, tfs fs.FS, pkg *apk.Package) (bool, error) {
 	switch hdr.Typeflag {
 	case tar.TypeDir: