diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index b7b928febaf0e5be6528a6428c3084474442b8e0..ef6cd0260ba1f0929607ac61f1abe46a55f57fef 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -36,6 +36,7 @@ add_executable (unit_tests
   test_INodeProcessor.cpp
   test_ItemType.cpp
   test_NameProcessor.cpp
+  test_OStreamProcessor.cpp
   test_PCG.cpp
   test_PugsAssert.cpp
   test_RevisionInfo.cpp
diff --git a/tests/test_OStreamProcessor.cpp b/tests/test_OStreamProcessor.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..be958502a5b6e62d01c458405e4440eca792c20d
--- /dev/null
+++ b/tests/test_OStreamProcessor.cpp
@@ -0,0 +1,79 @@
+#include <catch2/catch.hpp>
+
+#include <ASTNodeValueBuilder.hpp>
+
+#include <ASTBuilder.hpp>
+#include <ASTNodeDataTypeBuilder.hpp>
+
+#include <ASTNodeDeclarationCleaner.hpp>
+#include <ASTNodeDeclarationToAffectationConverter.hpp>
+
+#include <ASTNodeExpressionBuilder.hpp>
+
+#include <ASTNodeAffectationExpressionBuilder.hpp>
+
+#include <ASTSymbolTableBuilder.hpp>
+
+#include <ASTPrinter.hpp>
+
+#include <Demangle.hpp>
+
+#include <PEGGrammar.hpp>
+
+#include <node_processor/OStreamProcessor.hpp>
+
+#include <sstream>
+
+void
+_replaceOStream(ASTNode& node, std::ostringstream& sout)
+{
+  if (node.is<language::cout_kw>() or node.is<language::cerr_kw>()) {
+    node.m_node_processor = std::make_unique<OStreamProcessor>(node, sout);
+  } else {
+    for (auto& child_node : node.children) {
+      _replaceOStream(*child_node, sout);
+    }
+  }
+}
+
+#define CHECK_OSTREAM_EXPRESSION_RESULT(data, expected_value) \
+  {                                                           \
+    string_input input{data, "test.pgs"};                     \
+    auto ast = ASTBuilder::build(input);                      \
+                                                              \
+    ASTSymbolTableBuilder{*ast};                              \
+    ASTNodeDataTypeBuilder{*ast};                             \
+    ASTNodeValueBuilder{*ast};                                \
+                                                              \
+    ASTNodeDeclarationToAffectationConverter{*ast};           \
+    ASTNodeDeclarationCleaner{*ast};                          \
+                                                              \
+    ASTNodeExpressionBuilder{*ast};                           \
+    ExecUntilBreakOrContinue exec_policy;                     \
+                                                              \
+    std::ostringstream sout;                                  \
+    _replaceOStream(*ast, sout);                              \
+                                                              \
+    ast->execute(exec_policy);                                \
+                                                              \
+    REQUIRE(sout.str() == expected_value);                    \
+  }
+
+TEST_CASE("OStreamProcessor", "[language]")
+{
+  SECTION("cout")
+  {
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cout << 2;)", "2");
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cout << true;)", "true");
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cout << false;)", "false");
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cout << "x=" << 2 << "\n";)", "x=2\n");
+  }
+
+  SECTION("cerr")
+  {
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cerr << 2;)", "2");
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cerr << true;)", "true");
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cerr << false;)", "false");
+    CHECK_OSTREAM_EXPRESSION_RESULT(R"(cerr << "x=" << 2 << "\n";)", "x=2\n");
+  }
+}