add a test to write/read an EBML header

CMakeLists.txt

@@ -132,6 +132,10 @@ if (BUILD_TESTING)
   target_link_libraries(test_id PUBLIC ebml)
   add_test(test_id test_id)
 
+  add_executable(test_header test/test_header.cxx)
+  target_link_libraries(test_header PUBLIC ebml)
+  add_test(test_header test_header)
+
   add_executable(test_infinite test/test_infinite.cxx)
   target_link_libraries(test_infinite PUBLIC ebml)
   add_test(test_infinite test_infinite)

test/test_header.cxx

@@ -0,0 +1,66 @@
+// Copyright © 2024 Steve Lhomme.
+// SPDX-License-Identifier: ISC
+
+#include <ebml/EbmlHead.h>
+#include <ebml/EbmlSubHead.h>
+#include <ebml/EbmlMaster.h>
+#include <ebml/EbmlStream.h>
+#include <ebml/MemIOCallback.h>
+
+int main(int /*argc*/, char** /*argv*/)
+{
+    ///// Writing test
+    libebml::MemIOCallback Ebml_file;
+    libebml::EbmlHead TestHead;
+
+    libebml::EDocType & MyDocType = libebml::GetChild<libebml::EDocType>(TestHead);
+    MyDocType.SetValue("webm");
+
+    libebml::EDocTypeVersion & MyDocTypeVer = libebml::GetChild<libebml::EDocTypeVersion>(TestHead);
+    MyDocTypeVer.SetValue(1);
+
+    libebml::GetChild<libebml::EMaxSizeLength>(TestHead).SetValue(7);
+
+    auto length = TestHead.Render(Ebml_file, libebml::EbmlElement::WriteAll);
+    if (length != 36)
+        return 1;
+
+    ///// Reading test
+    Ebml_file.setFilePointer(0);
+    libebml::EbmlStream aStream(Ebml_file);
+    libebml::EbmlElement * ElementLevel0;
+
+    // find the EBML head in the file
+    ElementLevel0 = aStream.FindNextID(EBML_INFO(libebml::EbmlHead), 0xFFFFFFFFL);
+    if (ElementLevel0 == nullptr)
+        return 1;
+
+    if (ElementLevel0->GetClassId() != libebml::EbmlHead::ClassId())
+        return 1;
+
+    libebml::EbmlHead &ReadHead = static_cast<libebml::EbmlHead &>(*ElementLevel0);
+
+    int upper = 0;
+    ElementLevel0 = nullptr;
+    ReadHead.Read(aStream, EBML_CONTEXT(&ReadHead), upper, ElementLevel0, false);
+    if (ElementLevel0 != nullptr)
+        return 1;
+
+    if (upper != 0)
+        return 1;
+
+    libebml::EDocType & ReadDocType = libebml::GetChild<libebml::EDocType>(ReadHead);
+    const std::string & DocTypeStr = static_cast<const std::string &>(ReadDocType);
+    if (DocTypeStr != "webm")
+        return 1;
+
+    auto & ReadReadVersion = libebml::GetChild<const libebml::EDocTypeReadVersion>(ReadHead);
+    if (static_cast<std::uint64_t>(ReadReadVersion) != 1)
+        return 1;
+
+    auto & ReadMaxLength = libebml::GetChild<const libebml::EMaxSizeLength>(ReadHead);
+    if (static_cast<std::uint64_t>(ReadMaxLength) != 7)
+        return 1;
+
+    return 0;
+}