v3.42.34: Add spf13/afero for filesystem abstraction

- New internal/fs package for testable filesystem operations
- In-memory filesystem support for unit testing without disk I/O
- Swappable global FS: SetFS(afero.NewMemMapFs())
- Wrapper functions: ReadFile, WriteFile, Mkdir, Walk, Glob, etc.
- Testing helpers: WithMemFs(), SetupTestDir()
- Comprehensive test suite demonstrating usage
- Upgraded afero from v1.10.0 to v1.15.0

internal/fs/fs.go

@@ -0,0 +1,223 @@
+// Package fs provides filesystem abstraction using spf13/afero for testability.
+// It allows swapping the real filesystem with an in-memory mock for unit tests.
+package fs
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/spf13/afero"
+)
+
+// FS is the global filesystem interface used throughout the application.
+// By default, it uses the real OS filesystem.
+// For testing, use SetFS(afero.NewMemMapFs()) to use an in-memory filesystem.
+var FS afero.Fs = afero.NewOsFs()
+
+// SetFS sets the global filesystem (useful for testing)
+func SetFS(fs afero.Fs) {
+	FS = fs
+}
+
+// ResetFS resets to the real OS filesystem
+func ResetFS() {
+	FS = afero.NewOsFs()
+}
+
+// NewMemMapFs creates a new in-memory filesystem for testing
+func NewMemMapFs() afero.Fs {
+	return afero.NewMemMapFs()
+}
+
+// NewReadOnlyFs wraps a filesystem to make it read-only
+func NewReadOnlyFs(base afero.Fs) afero.Fs {
+	return afero.NewReadOnlyFs(base)
+}
+
+// NewBasePathFs creates a filesystem rooted at a specific path
+func NewBasePathFs(base afero.Fs, path string) afero.Fs {
+	return afero.NewBasePathFs(base, path)
+}
+
+// --- File Operations (use global FS) ---
+
+// Create creates a file
+func Create(name string) (afero.File, error) {
+	return FS.Create(name)
+}
+
+// Open opens a file for reading
+func Open(name string) (afero.File, error) {
+	return FS.Open(name)
+}
+
+// OpenFile opens a file with specified flags and permissions
+func OpenFile(name string, flag int, perm os.FileMode) (afero.File, error) {
+	return FS.OpenFile(name, flag, perm)
+}
+
+// Remove removes a file or empty directory
+func Remove(name string) error {
+	return FS.Remove(name)
+}
+
+// RemoveAll removes a path and any children it contains
+func RemoveAll(path string) error {
+	return FS.RemoveAll(path)
+}
+
+// Rename renames (moves) a file
+func Rename(oldname, newname string) error {
+	return FS.Rename(oldname, newname)
+}
+
+// Stat returns file info
+func Stat(name string) (os.FileInfo, error) {
+	return FS.Stat(name)
+}
+
+// Chmod changes file mode
+func Chmod(name string, mode os.FileMode) error {
+	return FS.Chmod(name, mode)
+}
+
+// Chown changes file ownership (may not work on all filesystems)
+func Chown(name string, uid, gid int) error {
+	return FS.Chown(name, uid, gid)
+}
+
+// Chtimes changes file access and modification times
+func Chtimes(name string, atime, mtime time.Time) error {
+	return FS.Chtimes(name, atime, mtime)
+}
+
+// --- Directory Operations ---
+
+// Mkdir creates a directory
+func Mkdir(name string, perm os.FileMode) error {
+	return FS.Mkdir(name, perm)
+}
+
+// MkdirAll creates a directory and all parents
+func MkdirAll(path string, perm os.FileMode) error {
+	return FS.MkdirAll(path, perm)
+}
+
+// ReadDir reads a directory
+func ReadDir(dirname string) ([]os.FileInfo, error) {
+	return afero.ReadDir(FS, dirname)
+}
+
+// --- File Content Operations ---
+
+// ReadFile reads an entire file
+func ReadFile(filename string) ([]byte, error) {
+	return afero.ReadFile(FS, filename)
+}
+
+// WriteFile writes data to a file
+func WriteFile(filename string, data []byte, perm os.FileMode) error {
+	return afero.WriteFile(FS, filename, data, perm)
+}
+
+// --- Existence Checks ---
+
+// Exists checks if a file or directory exists
+func Exists(path string) (bool, error) {
+	return afero.Exists(FS, path)
+}
+
+// DirExists checks if a directory exists
+func DirExists(path string) (bool, error) {
+	return afero.DirExists(FS, path)
+}
+
+// IsDir checks if path is a directory
+func IsDir(path string) (bool, error) {
+	return afero.IsDir(FS, path)
+}
+
+// IsEmpty checks if a directory is empty
+func IsEmpty(path string) (bool, error) {
+	return afero.IsEmpty(FS, path)
+}
+
+// --- Utility Functions ---
+
+// Walk walks a directory tree
+func Walk(root string, walkFn filepath.WalkFunc) error {
+	return afero.Walk(FS, root, walkFn)
+}
+
+// Glob returns the names of all files matching pattern
+func Glob(pattern string) ([]string, error) {
+	return afero.Glob(FS, pattern)
+}
+
+// TempDir creates a temporary directory
+func TempDir(dir, prefix string) (string, error) {
+	return afero.TempDir(FS, dir, prefix)
+}
+
+// TempFile creates a temporary file
+func TempFile(dir, pattern string) (afero.File, error) {
+	return afero.TempFile(FS, dir, pattern)
+}
+
+// CopyFile copies a file from src to dst
+func CopyFile(src, dst string) error {
+	srcFile, err := FS.Open(src)
+	if err != nil {
+		return err
+	}
+	defer srcFile.Close()
+
+	srcInfo, err := srcFile.Stat()
+	if err != nil {
+		return err
+	}
+
+	dstFile, err := FS.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, srcInfo.Mode())
+	if err != nil {
+		return err
+	}
+	defer dstFile.Close()
+
+	_, err = io.Copy(dstFile, srcFile)
+	return err
+}
+
+// FileSize returns the size of a file
+func FileSize(path string) (int64, error) {
+	info, err := FS.Stat(path)
+	if err != nil {
+		return 0, err
+	}
+	return info.Size(), nil
+}
+
+// --- Testing Helpers ---
+
+// WithMemFs executes a function with an in-memory filesystem, then restores the original
+func WithMemFs(fn func(fs afero.Fs)) {
+	original := FS
+	memFs := afero.NewMemMapFs()
+	FS = memFs
+	defer func() { FS = original }()
+	fn(memFs)
+}
+
+// SetupTestDir creates a test directory structure in-memory
+func SetupTestDir(files map[string]string) afero.Fs {
+	memFs := afero.NewMemMapFs()
+	for path, content := range files {
+		dir := filepath.Dir(path)
+		if dir != "." && dir != "/" {
+			_ = memFs.MkdirAll(dir, 0755)
+		}
+		_ = afero.WriteFile(memFs, path, []byte(content), 0644)
+	}
+	return memFs
+}

internal/fs/fs_test.go

@@ -0,0 +1,191 @@
+package fs
+
+import (
+	"os"
+	"testing"
+
+	"github.com/spf13/afero"
+)
+
+func TestMemMapFs(t *testing.T) {
+	// Use in-memory filesystem for testing
+	WithMemFs(func(memFs afero.Fs) {
+		// Create a file
+		err := WriteFile("/test/file.txt", []byte("hello world"), 0644)
+		if err != nil {
+			t.Fatalf("WriteFile failed: %v", err)
+		}
+
+		// Read it back
+		content, err := ReadFile("/test/file.txt")
+		if err != nil {
+			t.Fatalf("ReadFile failed: %v", err)
+		}
+
+		if string(content) != "hello world" {
+			t.Errorf("expected 'hello world', got '%s'", string(content))
+		}
+
+		// Check existence
+		exists, err := Exists("/test/file.txt")
+		if err != nil {
+			t.Fatalf("Exists failed: %v", err)
+		}
+		if !exists {
+			t.Error("file should exist")
+		}
+
+		// Check non-existent file
+		exists, err = Exists("/nonexistent.txt")
+		if err != nil {
+			t.Fatalf("Exists failed: %v", err)
+		}
+		if exists {
+			t.Error("file should not exist")
+		}
+	})
+}
+
+func TestSetupTestDir(t *testing.T) {
+	// Create test directory structure
+	testFs := SetupTestDir(map[string]string{
+		"/backups/db1.dump":     "database 1 content",
+		"/backups/db2.dump":     "database 2 content",
+		"/config/settings.json": `{"key": "value"}`,
+	})
+
+	// Verify files exist
+	content, err := afero.ReadFile(testFs, "/backups/db1.dump")
+	if err != nil {
+		t.Fatalf("ReadFile failed: %v", err)
+	}
+	if string(content) != "database 1 content" {
+		t.Errorf("unexpected content: %s", string(content))
+	}
+
+	// Verify directory structure
+	files, err := afero.ReadDir(testFs, "/backups")
+	if err != nil {
+		t.Fatalf("ReadDir failed: %v", err)
+	}
+	if len(files) != 2 {
+		t.Errorf("expected 2 files, got %d", len(files))
+	}
+}
+
+func TestCopyFile(t *testing.T) {
+	WithMemFs(func(memFs afero.Fs) {
+		// Create source file
+		err := WriteFile("/source.txt", []byte("copy me"), 0644)
+		if err != nil {
+			t.Fatalf("WriteFile failed: %v", err)
+		}
+
+		// Copy file
+		err = CopyFile("/source.txt", "/dest.txt")
+		if err != nil {
+			t.Fatalf("CopyFile failed: %v", err)
+		}
+
+		// Verify copy
+		content, err := ReadFile("/dest.txt")
+		if err != nil {
+			t.Fatalf("ReadFile failed: %v", err)
+		}
+		if string(content) != "copy me" {
+			t.Errorf("unexpected content: %s", string(content))
+		}
+	})
+}
+
+func TestFileSize(t *testing.T) {
+	WithMemFs(func(memFs afero.Fs) {
+		data := []byte("12345678901234567890") // 20 bytes
+		err := WriteFile("/sized.txt", data, 0644)
+		if err != nil {
+			t.Fatalf("WriteFile failed: %v", err)
+		}
+
+		size, err := FileSize("/sized.txt")
+		if err != nil {
+			t.Fatalf("FileSize failed: %v", err)
+		}
+		if size != 20 {
+			t.Errorf("expected size 20, got %d", size)
+		}
+	})
+}
+
+func TestTempDir(t *testing.T) {
+	WithMemFs(func(memFs afero.Fs) {
+		// Create temp dir
+		dir, err := TempDir("", "test-")
+		if err != nil {
+			t.Fatalf("TempDir failed: %v", err)
+		}
+
+		// Verify it exists
+		isDir, err := IsDir(dir)
+		if err != nil {
+			t.Fatalf("IsDir failed: %v", err)
+		}
+		if !isDir {
+			t.Error("temp dir should be a directory")
+		}
+
+		// Verify it's empty
+		isEmpty, err := IsEmpty(dir)
+		if err != nil {
+			t.Fatalf("IsEmpty failed: %v", err)
+		}
+		if !isEmpty {
+			t.Error("temp dir should be empty")
+		}
+	})
+}
+
+func TestWalk(t *testing.T) {
+	WithMemFs(func(memFs afero.Fs) {
+		// Create directory structure
+		_ = MkdirAll("/root/a/b", 0755)
+		_ = WriteFile("/root/file1.txt", []byte("1"), 0644)
+		_ = WriteFile("/root/a/file2.txt", []byte("2"), 0644)
+		_ = WriteFile("/root/a/b/file3.txt", []byte("3"), 0644)
+
+		var files []string
+		err := Walk("/root", func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+			if !info.IsDir() {
+				files = append(files, path)
+			}
+			return nil
+		})
+
+		if err != nil {
+			t.Fatalf("Walk failed: %v", err)
+		}
+
+		if len(files) != 3 {
+			t.Errorf("expected 3 files, got %d: %v", len(files), files)
+		}
+	})
+}
+
+func TestGlob(t *testing.T) {
+	WithMemFs(func(memFs afero.Fs) {
+		_ = WriteFile("/data/backup1.dump", []byte("1"), 0644)
+		_ = WriteFile("/data/backup2.dump", []byte("2"), 0644)
+		_ = WriteFile("/data/config.json", []byte("{}"), 0644)
+
+		matches, err := Glob("/data/*.dump")
+		if err != nil {
+			t.Fatalf("Glob failed: %v", err)
+		}
+
+		if len(matches) != 2 {
+			t.Errorf("expected 2 matches, got %d: %v", len(matches), matches)
+		}
+	})
+}