added IoBuffer.mmap test case

this verifies that attempting to map a range outside the underlying file
fails. Posix appears to offer different semantics so it
silently accepts it still however.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/zencore/iobuffer.cpp b/src/zencore/iobuffer.cpp
index 3aca0cfa7..6a4b56be6 100644
--- a/src/zencore/iobuffer.cpp
+++ b/src/zencore/iobuffer.cpp
@@ -680,6 +680,33 @@ TEST_CASE("IoBuffer")
 	zen::IoBuffer buffer3(buffer2, 0, buffer2.Size());
 }
 
+TEST_CASE("IoBuffer.mmap")
+{
+	zen::IoBuffer Buffer1{65536};
+	uint8_t*	  Mutate = Buffer1.MutableData<uint8_t>();
+	memcpy(Mutate, "abc123", 6);
+	zen::WriteFile("test_file.data", Buffer1);
+
+	SUBCASE("in-range")
+	{
+		zen::IoBuffer FileBuffer = IoBufferBuilder::MakeFromFile("test_file.data", 0, 65536);
+		const void*	  Data		 = FileBuffer.GetData();
+		CHECK(Data != nullptr);
+		CHECK_EQ(memcmp(Data, "abc123", 6), 0);
+	}
+
+	// Linux/MacOS offers different semantics when calling mmap with out-of-range so
+	// for now let's ignore whether that makes sense or not
+#	if ZEN_PLATFORM_WINDOWS
+	SUBCASE("out-of-range")
+	{
+		zen::IoBuffer FileBuffer = IoBufferBuilder::MakeFromFile("test_file.data", 131072, 65536);
+		const void*	  Data		 = nullptr;
+		CHECK_THROWS(Data = FileBuffer.GetData());
+		CHECK(Data == nullptr);
+	}
+#	endif
+}
 #endif
 
 }  // namespace zen