kapi: add device registry tests

1 files changed, 76 insertions, 0 deletions

diff --git a/kernel/kapi/devices.tests.cpp b/kernel/kapi/devices.tests.cpp
new file mode 100644
index 00000000..236a812d
--- /dev/null
+++ b/kernel/kapi/devices.tests.cpp
@@ -0,0 +1,76 @@
+#include <kapi/devices.hpp>
+
+#include <kstd/memory.hpp>
+
+#include <catch2/catch_test_macros.hpp>
+
+namespace
+{
+
+  struct test_bus final : kapi::devices::bus
+  {
+    using kapi::devices::bus::bus;
+  };
+
+  struct test_device final : kapi::devices::device
+  {
+    using kapi::devices::device::device;
+
+    auto init() -> bool override
+    {
+      return true;
+    }
+  };
+
+}  // namespace
+
+SCENARIO("the device registry holds devices weakly and prunes stale entries lazily", "[devices][registry]")
+{
+  GIVEN("a device attached to a bus, and therefore registered")
+  {
+    auto owner = kstd::make_shared<test_bus>("registry_test_owner");
+    owner->add_child(kstd::make_shared<test_device>("registry_test_device"));
+
+    THEN("it is discoverable via find_devices")
+    {
+      auto found = kapi::devices::find_device("registry_test_device");
+      REQUIRE(found);
+      REQUIRE(found->name() == "registry_test_device");
+    }
+
+    THEN("find_device reports no match for an uknown name")
+    {
+      REQUIRE_FALSE(kapi::devices::find_device("does_not_exist"));
+    }
+
+    WHEN("every strong reference to the device is dropped")
+    {
+      owner.reset();
+
+      THEN("find_device no longer resolves it")
+      {
+        REQUIRE_FALSE(kapi::devices::find_device("registry_test_device"));
+      }
+    }
+  }
+
+  GIVEN("a device name whose previous registration has since expired")
+  {
+    {
+      auto owner = kstd::make_shared<test_bus>("registry_reuse_owner_1");
+      owner->add_child(kstd::make_shared<test_device>("registry_reuse_device"));
+    }
+
+    WHEN("a new device is registered under the very same name")
+    {
+      auto new_device = kstd::make_shared<test_device>("registry_reuse_device");
+      auto registered = kapi::devices::register_device(new_device);
+
+      THEN("registration succeeds")
+      {
+        REQUIRE(registered);
+        REQUIRE(kapi::devices::find_device("registry_reuse_device") == new_device);
+      }
+    }
+  }
+}