diff --git a/src/frontend/parser.cpp b/src/frontend/parser.cpp
index 2cbd8be41..af1a6acbf 100644
--- a/src/frontend/parser.cpp
+++ b/src/frontend/parser.cpp
@@ -128,6 +128,7 @@ struct parser_fn {
     }
 
     [[ noreturn ]] void not_implemented_yet() {
+        // TODO
         throw parser_error("not implemented yet");
     }
 
diff --git a/src/shell/CMakeLists.txt b/src/shell/CMakeLists.txt
index 0a456c9b4..d0b8e6d4e 100644
--- a/src/shell/CMakeLists.txt
+++ b/src/shell/CMakeLists.txt
@@ -2,3 +2,9 @@ configure_file("${LEAN_SOURCE_DIR}/shell/version.h.in" "${LEAN_BINARY_DIR}/versi
 include_directories("${LEAN_BINARY_DIR}")
 add_executable(lean lean.cpp)
 target_link_libraries(lean ${EXTRA_LIBS})
+add_test(lean1 ${CMAKE_CURRENT_BINARY_DIR}/lean "${LEAN_SOURCE_DIR}/../examples/ex1.lean")
+add_test(lean2 ${CMAKE_CURRENT_BINARY_DIR}/lean "${LEAN_SOURCE_DIR}/../examples/ex2.lean")
+add_test(lean3 ${CMAKE_CURRENT_BINARY_DIR}/lean "${LEAN_SOURCE_DIR}/../examples/ex3.lean")
+add_test(lean4 ${CMAKE_CURRENT_BINARY_DIR}/lean "${LEAN_SOURCE_DIR}/../examples/ex4.lean")
+add_test(lean5 ${CMAKE_CURRENT_BINARY_DIR}/lean "${LEAN_SOURCE_DIR}/../examples/ex5.lean")
+add_test(lean6 ${CMAKE_CURRENT_BINARY_DIR}/lean "${LEAN_SOURCE_DIR}/../examples/ex6.lean")