added a test runner

run_tests.py

@@ -0,0 +1,30 @@
+"""
+# run_tests.py
+
+A helper script to test all of comet's features. This script reads the "tests" folder
+and executes each comet file, making sure it doesn't fail to compile.
+
+**Note:** This script requires that the cometc executable is in the same folder as the script, same with the tests folder.
+"""
+import unittest
+import os
+import subprocess
+
+
+TESTS_FOLDER_NAME = "tests"
+
+
+class CometTester(unittest.TestCase):
+    def test_comet(self):
+        cases = os.listdir(TESTS_FOLDER_NAME)
+        
+        self.assertTrue(os.path.isfile("./cometc"), "The comet compiler was not found in the same path as run_tests.py! Is there a \"cometc\" executable in the same folder?")
+        
+        for case in cases:
+            with self.subTest():
+                result = subprocess.run(["./cometc", f"{TESTS_FOLDER_NAME}/{case}"])
+                self.assertEqual(result.returncode, 0, f"{case} did not compile successfully!")
+        
+
+if __name__ == "__main__":
+    unittest.main()