1 files changed, 60 insertions, 0 deletions
diff --git a/kernel/src/filesystem/open_file_description.tests.cpp b/kernel/src/filesystem/open_file_description.tests.cpp
new file mode 100644
index 0000000..f045094
--- /dev/null
+++ b/kernel/src/filesystem/open_file_description.tests.cpp
@@ -0,0 +1,60 @@
+#include "kernel/filesystem/open_file_description.hpp"
+
+#include "kernel/test_support/filesystem/inode.hpp"
+
+#include <kstd/memory>
+#include <kstd/print>
+#include <kstd/vector>
+
+#include <catch2/catch_test_macros.hpp>
+
+SCENARIO("Open file description construction", "[filesystem][open_file_description]")
+{
+  GIVEN("an inode and an open file description for that inode")
+  {
+    auto inode = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto file_description = kernel::filesystem::open_file_description{inode};
+
+    THEN("the initial offset is zero")
+    {
+      REQUIRE(file_description.offset() == 0);
+    }
+  }
+}
+
+SCENARIO("Open file description read/write offset management", "[filesystem][open_file_description]")
+{
+  GIVEN("an inode that tracks read/write calls and an open file description for that inode")
+  {
+    auto inode = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto file_description = kernel::filesystem::open_file_description{inode};
+
+    THEN("the offset is updated correctly after reads")
+    {
+      REQUIRE(file_description.read(nullptr, 100) == 100);
+      REQUIRE(file_description.offset() == 100);
+      REQUIRE(file_description.read(nullptr, 50) == 50);
+      REQUIRE(file_description.offset() == 150);
+    }
+
+    THEN("the offset is updated correctly after writes")
+    {
+      REQUIRE(file_description.write(nullptr, 200) == 200);
+      REQUIRE(file_description.offset() == 200);
+      REQUIRE(file_description.write(nullptr, 25) == 25);
+      REQUIRE(file_description.offset() == 225);
+    }
+
+    THEN("reads and writes both update the same offset")
+    {
+      REQUIRE(file_description.read(nullptr, 10) == 10);
+      REQUIRE(file_description.offset() == 10);
+      REQUIRE(file_description.write(nullptr, 20) == 20);
+      REQUIRE(file_description.offset() == 30);
+      REQUIRE(file_description.read(nullptr, 5) == 5);
+      REQUIRE(file_description.offset() == 35);
+      REQUIRE(file_description.write(nullptr, 15) == 15);
+      REQUIRE(file_description.offset() == 50);
+    }
+  }
+}