diff --git a/core-writer/test/mock/TestH5Format.cpp b/core-writer/test/mock/TestH5Format.cpp
new file mode 100644
index 0000000..04a945b
--- /dev/null
+++ b/core-writer/test/mock/TestH5Format.cpp
@@ -0,0 +1,73 @@
+#include <memory>
+#include <unordered_map>
+#include <iostream>
+
+#include "config.hpp"
+#include "H5Format.hpp"
+
+using namespace std;
+using s_ptr = shared_ptr<h5_base>;
+
+class TestH5Format : public H5Format
+{
+    shared_ptr<unordered_map<string, DATA_TYPE>> input_value_type = NULL;
+    shared_ptr<unordered_map<string, boost::any>> default_values = NULL;
+    shared_ptr<unordered_map<string, std::string>> dataset_move_mapping = NULL;
+    shared_ptr<h5_parent> file_format = NULL;
+
+public:
+    ~TestH5Format(){};
+
+    TestH5Format(const string& dataset_name)
+    {
+        input_value_type.reset(new unordered_map<string, DATA_TYPE>());
+        default_values.reset(new unordered_map<string, boost::any>());
+
+        // After format has been writen, where to move the raw datasets.
+        dataset_move_mapping.reset(
+                new std::unordered_map<string, string>({}));
+
+        // Definition of the file format.
+        file_format.reset(
+                new h5_parent("", EMPTY_ROOT, {
+                        s_ptr(new h5_group("detector", {}))
+                }));
+    }
+
+    const h5_parent& get_format_definition() const override
+    {
+        return *file_format;
+    }
+
+    const unordered_map<string, boost::any>& get_default_values() const override
+    {
+        return *default_values;
+    }
+
+    void add_calculated_values(unordered_map<string, boost::any>& values) const override
+    {
+        // No calculated values.
+    }
+
+    void add_input_values(unordered_map<string, boost::any>& values,
+                          const unordered_map<string, boost::any>& input_values) const override
+    {
+        // Input value mapping is 1:1.
+        for (const auto& input_value : input_values) {
+            const auto& name = input_value.first;
+            const auto& value = input_value.second;
+
+            values[name] = value;
+        }
+    }
+
+    const std::unordered_map<string, DATA_TYPE>& get_input_value_type() const override
+    {
+        return *input_value_type;
+    }
+
+    const unordered_map<string, string>& get_dataset_move_mapping() const override {
+        return *dataset_move_mapping;
+    }
+
+};