Add new option: run in run_tests to save the runtime error or output

run_tests.py

@@ -25,6 +25,7 @@ def is_included(backend):
     cpp = is_included("cpp")
     c = is_included("c")
     wat = is_included("wat")
+    run = is_included("run")
     pass_ = test.get("pass", None)
     optimization_passes = ["flip_sign", "div_to_mul", "fma", "sign_from_value",
                            "inline_function_calls", "loop_unroll",
@@ -102,7 +103,9 @@ def is_included(backend):
         run_test(filename, "wat", "lpython --no-color --show-wat {infile}",
                  filename, update_reference, extra_args)
 
-
+    if run:
+        run_test(filename, "runtime", "lpython {infile}",
+                 filename, update_reference, extra_args)
 
 if __name__ == "__main__":
     tester_main("LPython", single_test)

tests/tests.toml

@@ -4,6 +4,8 @@
 # asr ... run the Semantics and output ASR, compare against reference version
 # llvm ... run the Semantics and output LLVM, compare against reference version
 # tokens ... output Tokens, compare against reference version
+# run ... compiles and executes the specified file;
+#         checks both runtime errors and successful runs
 
 # tests