internal/uevent: enumerate objects via sysfs

This is not a great way to implement cold boot, but I already have the implementation lying around.

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

internal/uevent/sysfs_test.go

@@ -0,0 +1,28 @@
+package uevent_test
+
+import (
+	"os"
+	"sync"
+	"testing"
+
+	"hakurei.app/internal/uevent"
+)
+
+func TestEnumerate(t *testing.T) {
+	t.Parallel()
+
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	events := make(chan *uevent.Message, 1<<10)
+	wg.Go(func() {
+		for msg := range events {
+			t.Log(msg)
+		}
+	})
+
+	if err := uevent.Enumerate(os.DirFS("/sys"), nil, events); err != nil {
+		t.Fatalf("Enumerate: error = %v", err)
+	}
+	close(events)
+}