test/sandbox/assert: wrap printf

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

test/sandbox/assert.go

@@ -8,9 +8,11 @@ import (
 
 var (
 	assert     = log.New(os.Stderr, "sandbox: ", 0)
+	printfFunc = assert.Printf
 	fatalfFunc = assert.Fatalf
 )
 
+func printf(format string, v ...any) { printfFunc(format, v...) }
 func fatalf(format string, v ...any) { fatalfFunc(format, v...) }
 
 func MustAssertMounts(name, hostMountsFile, wantFile string) {
@@ -53,7 +55,7 @@ func MustAssertMounts(name, hostMountsFile, wantFile string) {
 				e, &want[i])
 		}
 
-		assert.Printf("%s", e)
+		printf("%s", e)
 		i++
 	}); err != nil {
 		fatalf("cannot iterate mounts: %v", err)

test/sandbox/assert_test.go

@@ -1,3 +1,6 @@
 package sandbox
 
-func ReplaceFatal(f func(format string, v ...any)) { fatalfFunc = f }
+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 }

test/sandbox/mount_test.go

@@ -111,7 +111,8 @@ overlay /.fortify/sbin/fortify overlay ro,nosuid,nodev,relatime,lowerdir=/mnt-ro
 		})
 
 		t.Run(tc.name+" assert", func(t *testing.T) {
-			sandbox.ReplaceFatal(t.Fatalf)
+			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 {