2 files changed, 65 insertions, 0 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt
index bb68832..390afbc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,6 +14,11 @@ FetchContent_Declare("asio"
   GIT_TAG "asio-1-38-0"
 )
 
+FetchContent_Declare("catch2"
+  GIT_REPOSITORY "https://github.com/catchorg/Catch2.git"
+  GIT_TAG "v3.15.1"
+)
+
 FetchContent_Declare("sml"
   GIT_REPOSITORY "https://github.com/boost-ext/sml"
   GIT_TAG "v1.2.0"
@@ -21,6 +26,7 @@ FetchContent_Declare("sml"
 
 FetchContent_MakeAvailable(
   "asio"
+  "catch2"
   "sml"
 )
 
@@ -94,3 +100,24 @@ target_link_libraries("ttwhy" PRIVATE
   "ttwhy::lib"
 )
 
+### Tests
+
+include("CTest")
+
+if(BUILD_TESTING)
+  include("Catch")
+
+  add_executable("ttwhy-tests")
+  add_executable("ttwhy::tests" ALIAS "ttwhy-tests")
+
+  target_sources("ttwhy-tests" PRIVATE
+    "ttwhy/scanners/ansi.tests.cpp"
+  )
+
+  target_link_libraries("ttwhy-tests" PRIVATE
+    "ttwhy::lib"
+    "Catch2::Catch2WithMain"
+  )
+
+  catch_discover_tests("ttwhy-tests")
+endif()
diff --git a/ttwhy/scanners/ansi.tests.cpp b/ttwhy/scanners/ansi.tests.cpp
new file mode 100644
index 0000000..6fdc8af
--- /dev/null
+++ b/ttwhy/scanners/ansi.tests.cpp
@@ -0,0 +1,38 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include <string_view>  // IWYU pragma: keep
+#include <variant>
+#include <vector>
+
+import ttwhy.scanners;
+
+using namespace std::string_view_literals;
+
+[[nodiscard]] constexpr auto static is_character(ttwhy::scanners::input_event & event, char expected) -> bool
+{
+  auto const * data = std::get_if<ttwhy::scanners::character_event>(&event);
+  return data != nullptr && data->value == expected;
+}
+
+SCENARIO("The ANSI scanner processes printable ASCII and standard C0 control characters", "[scanner][ansi]")
+{
+  GIVEN("An initialized scanner and event sink")
+  {
+    auto queue = std::vector<ttwhy::scanners::input_event>{};
+    auto sink = [&queue](auto const & event) {
+      queue.push_back(event);
+    };
+    auto scanner = ttwhy::scanners::ansi{sink};
+
+    WHEN("Processing a standard printable character")
+    {
+      scanner.process("A");
+
+      THEN("It yields a single character event")
+      {
+        REQUIRE(queue.size() == 1);
+        CHECK(is_character(queue.at(0), 'A'));
+      }
+    }
+  }
+}