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)
+	}
+}

test/sandbox/assert_test.go

@@ -1,6 +1,32 @@
 package sandbox
 
+import (
+	"encoding/json"
+	"os"
+	"path"
+	"testing"
+)
+
 type F func(format string, v ...any)
 
 func SwapPrint(f F) (old F) { old = printfFunc; printfFunc = f; return }
 func SwapFatal(f F) (old F) { old = fatalfFunc; fatalfFunc = f; return }
+
+func MustWantFile(t *testing.T, v any) (wantFile string) {
+	wantFile = path.Join(t.TempDir(), "want.json")
+	if f, err := os.OpenFile(wantFile, os.O_CREATE|os.O_WRONLY, 0400); err != nil {
+		t.Fatalf("cannot create %q: %v", wantFile, err)
+	} else if err = json.NewEncoder(f).Encode(v); err != nil {
+		t.Fatalf("cannot encode to %q: %v", wantFile, err)
+	} else if err = f.Close(); err != nil {
+		t.Fatalf("cannot close %q: %v", wantFile, err)
+	}
+
+	t.Cleanup(func() {
+		if err := os.Remove(wantFile); err != nil {
+			t.Fatalf("cannot remove %q: %v", wantFile, err)
+		}
+	})
+
+	return
+}

test/sandbox/fs_test.go

@@ -75,4 +75,10 @@ func TestCompare(t *testing.T) {
 			}
 		})
 	}
+
+	t.Run("assert", func(t *testing.T) {
+		oldFatal := sandbox.SwapFatal(t.Fatalf)
+		t.Cleanup(func() { sandbox.SwapFatal(oldFatal) })
+		sandbox.MustAssertFS(make(fstest.MapFS), sandbox.MustWantFile(t, &sandbox.FS{Mode: 0xDEADBEEF}))
+	})
 }

test/sandbox/mount_test.go

@@ -1,7 +1,6 @@
 package sandbox_test
 
 import (
-	"encoding/json"
 	"os"
 	"path"
 	"testing"
@@ -113,21 +112,7 @@ overlay /.fortify/sbin/fortify overlay ro,nosuid,nodev,relatime,lowerdir=/mnt-ro
 		t.Run(tc.name+" assert", func(t *testing.T) {
 			oldFatal := sandbox.SwapFatal(t.Fatalf)
 			t.Cleanup(func() { sandbox.SwapFatal(oldFatal) })
-
-			wantFile := path.Join(t.TempDir(), "want.json")
-			if f, err := os.OpenFile(wantFile, os.O_CREATE|os.O_WRONLY, 0400); err != nil {
-				t.Fatalf("cannot create %q: %v", wantFile, err)
-			} else if err = json.NewEncoder(f).Encode(tc.want); err != nil {
-				t.Fatalf("cannot encode to %q: %v", wantFile, err)
-			} else if err = f.Close(); err != nil {
-				t.Fatalf("cannot close %q: %v", wantFile, err)
-			}
-
-			sandbox.MustAssertMounts(name, name, wantFile)
-
-			if err := os.Remove(wantFile); err != nil {
-				t.Fatalf("cannot remove %q: %v", wantFile, err)
-			}
+			sandbox.MustAssertMounts(name, name, sandbox.MustWantFile(t, tc.want))
 		})
 
 		if err := os.Remove(name); err != nil {