Add tests module

tests/test_cli.py

@@ -0,0 +1,19 @@
+import pytest
+from click.testing import CliRunner
+from src.cli import main, check, validate
+
+class TestCLI:
+    def setup_method(self):
+        self.runner = CliRunner()
+
+    def test_main_help(self):
+        r = self.runner.invoke(main, ["--help"])
+        assert r.exit_code == 0
+
+    def test_check_safe(self):
+        r = self.runner.invoke(check, ["echo test"])
+        assert r.exit_code == 0
+
+    def test_check_dangerous(self):
+        r = self.runner.invoke(check, ["rm -rf $TARGET"])
+        assert r.exit_code == 1