Written a test case to test size on loading

src/test/blobstore/ondisk/OnDiskBlobLoadTest.cpp

@@ -3,17 +3,40 @@
 #include "test/testutils/TempFile.h"
 
 #include "blobstore/implementations/ondisk/OnDiskBlob.h"
+#include "blobstore/implementations/ondisk/Data.h"
+
+#include <fstream>
 
 using ::testing::Test;
+using ::testing::WithParamInterface;
+using ::testing::Values;
 
+using std::ofstream;
 using std::unique_ptr;
+using std::ios;
 
-using blobstore::ondisk::OnDiskBlob;
+using namespace blobstore::ondisk;
 
 namespace bf = boost::filesystem;
 
 class OnDiskBlobLoadTest: public Test {
 public:
   TempFile file;
+
+  void SetFileSize(size_t size) {
+    Data data(size);
+    ofstream writer(file.path().c_str(), ios::trunc | ios::binary);
+    writer.write((char*)data.data(), size);
+  }
 };
 
+class OnDiskBlobLoadSizeTest: public OnDiskBlobLoadTest, public WithParamInterface<size_t> {};
+INSTANTIATE_TEST_CASE_P(OnDiskBlobLoadSizeTest, OnDiskBlobLoadSizeTest, Values(0, 1, 5, 1024, 10*1024*1024));
+
+TEST_P(OnDiskBlobLoadSizeTest, FileSizeIsCorrect) {
+  SetFileSize(GetParam());
+
+  auto blob = OnDiskBlob::LoadFromDisk(file.path());
+
+  EXPECT_EQ(GetParam(), blob->size());
+}