test/sandbox: compare filesystem hierarchy

For checking deterministic aspects of fs outcome.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 98 insertions, 0 deletions

diff --git a/test/sandbox/fs.go b/test/sandbox/fs.go
new file mode 100644
index 00000000..fd1aa2c5
--- /dev/null
+++ b/test/sandbox/fs.go
@@ -0,0 +1,98 @@
+package sandbox
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"path"
+	"strings"
+)
+
+var (
+	ErrFSBadLength  = errors.New("bad dir length")
+	ErrFSBadData    = errors.New("data differs")
+	ErrFSBadMode    = errors.New("mode differs")
+	ErrFSInvalidEnt = errors.New("invalid entry condition")
+)
+
+type FS struct {
+	Mode fs.FileMode    `json:"mode"`
+	Dir  map[string]*FS `json:"dir"`
+	Data *string        `json:"data"`
+}
+
+func printDir(prefix string, dir []fs.DirEntry) {
+	names := make([]string, len(dir))
+	for i, ent := range dir {
+		name := ent.Name()
+		if ent.IsDir() {
+			name += "/"
+		}
+		names[i] = fmt.Sprintf("%q", name)
+	}
+	printf("[FAIL] d %q: %s", prefix, strings.Join(names, " "))
+}
+
+func (s *FS) Compare(prefix string, e fs.FS) error {
+	if s.Data != nil {
+		if s.Dir != nil {
+			panic("invalid state")
+		}
+		panic("invalid compare call")
+	}
+
+	if s.Dir == nil {
+		printf("[ OK ] s %s", prefix)
+		return nil
+	}
+
+	var dir []fs.DirEntry
+	if d, err := fs.ReadDir(e, prefix); err != nil {
+		return err
+	} else if len(d) != len(s.Dir) {
+		printDir(prefix, d)
+		return ErrFSBadLength
+	} else {
+		dir = d
+	}
+
+	for _, got := range dir {
+		name := got.Name()
+
+		if want, ok := s.Dir[name]; !ok {
+			printDir(prefix, dir)
+			return fs.ErrNotExist
+		} else if want.Dir != nil && !got.IsDir() {
+			printDir(prefix, dir)
+			return ErrFSInvalidEnt
+		} else {
+			name = path.Join(prefix, name)
+
+			if fi, err := got.Info(); err != nil {
+				return err
+			} else if fi.Mode() != want.Mode {
+				printf("[FAIL] m %q: %x, want %x",
+					name, uint32(fi.Mode()), uint32(want.Mode))
+				return ErrFSBadMode
+			}
+
+			if want.Data != nil {
+				if want.Dir != nil {
+					panic("invalid state")
+				}
+				if v, err := fs.ReadFile(e, name); err != nil {
+					return err
+				} else if string(v) != *want.Data {
+					printf("[FAIL] f %s", name)
+					return ErrFSBadData
+				}
+				printf("[ OK ] f %s", name)
+			} else if err := want.Compare(name, e); err != nil {
+				return err
+			}
+		}
+	}
+	printf("[ OK ] d %s", prefix)
+
+	return nil
+}