From 15d38c630052f43c980bdea60723ce388077437f Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Sun, 26 Jul 2026 13:41:56 +0200
Subject: kernel: add devfs live-update tests

---
 kernel/kapi/devices.cpp                            | 11 +++++
 .../kernel/filesystem/devfs/filesystem.tests.cpp   | 53 +++++++++++++++++++++-
 2 files changed, 63 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/kapi/devices.cpp b/kernel/kapi/devices.cpp
index f289bbf2..4480206a 100644
--- a/kernel/kapi/devices.cpp
+++ b/kernel/kapi/devices.cpp
@@ -42,6 +42,17 @@ namespace kapi::devices
     return root_bus;
   }
 
+  auto remove_device(device & device) -> bool
+  {
+    auto parent = device.parent();
+    if (!parent)
+    {
+      return false;
+    }
+
+    return parent->remove_child(device);
+  }
+
 }  // namespace kapi::devices
 
 namespace kapi::test_support::devices
diff --git a/kernel/kernel/filesystem/devfs/filesystem.tests.cpp b/kernel/kernel/filesystem/devfs/filesystem.tests.cpp
index 29a33231..28da5275 100644
--- a/kernel/kernel/filesystem/devfs/filesystem.tests.cpp
+++ b/kernel/kernel/filesystem/devfs/filesystem.tests.cpp
@@ -2,14 +2,24 @@
 
 #include <kernel/filesystem/filesystem.hpp>
 #include <kernel/filesystem/vfs_types.hpp>
+#include <kernel/test_support/devices/block_device.hpp>
+#include <kernel/test_support/devices/driver.hpp>
 #include <kernel/test_support/filesystem/storage_boot_module_fixture.hpp>
 
+#include <kapi/devices.hpp>
+#include <kapi/filesystem.hpp>
+
 #include <kstd/memory.hpp>
+#include <kstd/units.hpp>
 
 #include <catch2/catch_test_macros.hpp>
 
+#include <cstdint>
+
+using namespace kstd::units_literals;
+
 SCENARIO_METHOD(kernel::tests::filesystem::storage_boot_module_fixture,
-                "Devfs filesystem lookup uses storage management devices", "[filesystem][devfs][filesystem]")
+                "Devfs filesystem lookup uses storage management devices", "[filesystem][devfs]")
 {
   GIVEN("a boot module registry with one module")
   {
@@ -80,3 +90,44 @@ SCENARIO_METHOD(kernel::tests::filesystem::storage_boot_module_fixture,
     }
   }
 }
+
+SCENARIO("Devfs filesystem updates", "[filesystem][devfs]")
+{
+  GIVEN("A mounted devfs, and a bus attached to the root without a device attached")
+  {
+    auto fs = kstd::make_shared<kernel::filesystem::devfs::filesystem>();
+    REQUIRE(fs->mount(nullptr));
+
+    auto bus = kstd::make_shared<kapi::devices::bus>("devfs_live_update_bus");
+    kapi::devices::get_root_bus()->add_child(bus);
+
+    REQUIRE_FALSE(fs->lookup(fs->root_inode(), "devfs_live_update_device_node"));
+
+    WHEN("a device is attached, bound, and published")
+    {
+      auto device = kstd::make_shared<kernel::tests::devices::block_device>("devfs_live_update_device", 512_B);
+      bus->add_child(device);
+      CHECK(kernel::tests::devices::bind(*device, std::uint8_t{99}));
+
+      REQUIRE(
+          kapi::devices::publish_facet<kapi::filesystem::block_special_file>(device, "devfs_live_update_device_node"));
+
+      THEN("devfs finds it immediately")
+      {
+        REQUIRE(fs->lookup(fs->root_inode(), "devfs_live_update_device_node"));
+      }
+
+      WHEN("the device is detached")
+      {
+        REQUIRE(kapi::devices::remove_device(*device));
+
+        THEN("devfs does not find it anymore")
+        {
+          REQUIRE_FALSE(fs->lookup(fs->root_inode(), "devfs_live_update_device_node"));
+        }
+      }
+    }
+
+    REQUIRE(kapi::devices::remove_device(*bus));
+  }
+}
\ No newline at end of file
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