all: optionally forbid degrading in tests

This enables transparently degradable tests to be forced on in environments known to support them.

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

internal/acl/acl_test.go

@@ -11,9 +11,11 @@ import (
 	"path/filepath"
 	"reflect"
 	"strconv"
+	"syscall"
 	"testing"
 
 	"hakurei.app/internal/acl"
+	"hakurei.app/internal/info"
 )
 
 const testFileName = "acl.test"
@@ -24,8 +26,14 @@ var (
 )
 
 func TestUpdate(t *testing.T) {
-	if os.Getenv("HAKUREI_TEST_SKIP_ACL") == "1" {
-		t.Skip("acl test skipped")
+	if info.CanDegrade {
+		name := filepath.Join(t.TempDir(), "check-degrade")
+		if err := os.WriteFile(name, nil, 0); err != nil {
+			t.Fatal(err)
+		}
+		if err := acl.Update(name, os.Geteuid()); errors.Is(err, syscall.ENOTSUP) {
+			t.Skip(err)
+		}
 	}
 
 	testFilePath := filepath.Join(t.TempDir(), testFileName)

internal/info/optional_skip.go

@@ -0,0 +1,7 @@
+//go:build !noskip
+
+package info
+
+// CanDegrade is whether tests are allowed to transparently degrade or skip due
+// to required system features being denied or unavailable.
+const CanDegrade = true

internal/info/optional_strict.go

@@ -0,0 +1,5 @@
+//go:build noskip
+
+package info
+
+const CanDegrade = false

internal/pkg/pkg_test.go

@@ -24,6 +24,7 @@ import (
 	"hakurei.app/check"
 	"hakurei.app/container"
 	"hakurei.app/fhs"
+	"hakurei.app/internal/info"
 	"hakurei.app/internal/pkg"
 	"hakurei.app/internal/stub"
 	"hakurei.app/message"
@@ -290,12 +291,15 @@ func checkWithCache(t *testing.T, testCases []cacheTestCase) {
 			msg.SwapVerbose(testing.Verbose())
 
 			flags := tc.flags
-			if _, err := container.LandlockGetABI(); err != nil {
-				if !errors.Is(err, syscall.ENOSYS) {
-					t.Fatalf("LandlockGetABI: error = %v", err)
+
+			if info.CanDegrade {
+				if _, err := container.LandlockGetABI(); err != nil {
+					if !errors.Is(err, syscall.ENOSYS) {
+						t.Fatalf("LandlockGetABI: error = %v", err)
+					}
+					flags |= pkg.CHostAbstract
+					t.Log("Landlock LSM is unavailable, setting CHostAbstract")
 				}
-				flags |= pkg.CHostAbstract
-				t.Log("Landlock LSM is unavailable, setting CHostAbstract")
 			}
 
 			var scrubFunc func() error // scrub after hashing