test/sandbox: assert filesystem json

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

test/sandbox/assert.go

@@ -2,6 +2,7 @@ package sandbox
 
 import (
 	"encoding/json"
+	"io/fs"
 	"log"
 	"os"
 )
@@ -15,6 +16,16 @@ var (
 func printf(format string, v ...any) { printfFunc(format, v...) }
 func fatalf(format string, v ...any) { fatalfFunc(format, v...) }
 
+func mustDecode(wantFile string, v any) {
+	if f, err := os.Open(wantFile); err != nil {
+		fatalf("cannot open %q: %v", wantFile, err)
+	} else if err = json.NewDecoder(f).Decode(v); err != nil {
+		fatalf("cannot decode %q: %v", wantFile, err)
+	} else if err = f.Close(); err != nil {
+		fatalf("cannot close %q: %v", wantFile, err)
+	}
+}
+
 func MustAssertMounts(name, hostMountsFile, wantFile string) {
 	hostMounts := make([]*Mntent, 0, 128)
 	if err := IterMounts(hostMountsFile, func(e *Mntent) {
@@ -24,13 +35,7 @@ func MustAssertMounts(name, hostMountsFile, wantFile string) {
 	}
 
 	var want []Mntent
-	if f, err := os.Open(wantFile); err != nil {
-		fatalf("cannot open %q: %v", wantFile, err)
-	} else if err = json.NewDecoder(f).Decode(&want); err != nil {
-		fatalf("cannot decode %q: %v", wantFile, err)
-	} else if err = f.Close(); err != nil {
-		fatalf("cannot close %q: %v", wantFile, err)
-	}
+	mustDecode(wantFile, &want)
 
 	for i := range want {
 		if want[i].Opts == "host_passthrough" {
@@ -61,3 +66,15 @@ func MustAssertMounts(name, hostMountsFile, wantFile string) {
 		fatalf("cannot iterate mounts: %v", err)
 	}
 }
+
+func MustAssertFS(e fs.FS, wantFile string) {
+	var want *FS
+	mustDecode(wantFile, &want)
+	if want == nil {
+		fatalf("invalid payload")
+	}
+
+	if err := want.Compare(".", e); err != nil {
+		fatalf("%v", err)
+	}
+}