Add unit tests for AST dotfile generator

tests/CMakeLists.txt

@@ -3,12 +3,13 @@ set(EXECUTABLE_OUTPUT_PATH ${PUGS_BINARY_DIR})
 
 add_executable (unit_tests
   test_main.cpp
-  test_ASTSymbolTableBuilder.cpp
-  test_ASTSymbolInitializationChecker.cpp
-  test_ASTBuilder.cpp
-  test_ASTNodeDataType.cpp
   test_Array.cpp
   test_ArrayUtils.cpp
+  test_ASTDotPrinter.cpp
+  test_ASTBuilder.cpp
+  test_ASTNodeDataType.cpp
+  test_ASTSymbolTableBuilder.cpp
+  test_ASTSymbolInitializationChecker.cpp
   test_ItemType.cpp
   test_PugsAssert.cpp
   test_RevisionInfo.cpp

tests/test_ASTDotPrinter.cpp

+#include <catch2/catch.hpp>
+
+#include <ASTBuilder.hpp>
+#include <ASTDotPrinter.hpp>
+#include <sstream>
+
+#define CHECK_DOT(data, expected_output)                                                      \
+  {                                                                                           \
+    static_assert(std::is_same_v<std::decay_t<decltype(data)>, std::string_view>);            \
+    static_assert(std::is_same_v<std::decay_t<decltype(expected_output)>, std::string_view>); \
+                                                                                              \
+    string_input input{data, "test.pgs"};                                                     \
+    auto ast = ASTBuilder::build(input);                                                      \
+                                                                                              \
+    std::stringstream ast_output;                                                             \
+    ast_output << '\n' << ASTDotPrinter{*ast};                                                \
+                                                                                              \
+    REQUIRE(ast_output.str() == expected_output);                                             \
+  }
+
+TEST_CASE("ASTDotPrinter", "[language]")
+{
+  rang::setControlMode(rang::control::Off);
+
+  std::string_view data = R"(
+N n = 2 + 3;
+)";
+
+  std::string_view result = R"(
+digraph parse_tree
+{
+  x0 [ label="root \nundefined" ]
+  x0 -> { x1 }
+  x1 [ label="language::declaration\nN n = 2 + 3\nundefined" ]
+  x1 -> { x2, x3, x4 }
+  x2 [ label="language::N_set\nN\nundefined" ]
+  x3 [ label="language::name\nn\nundefined" ]
+  x4 [ label="language::plus_op\nundefined" ]
+  x4 -> { x5, x6 }
+  x5 [ label="language::integer\n2\nundefined" ]
+  x6 [ label="language::integer\n3\nundefined" ]
+}
+)";
+  CHECK_DOT(data, result);
+}