Add a UT to test if ransomware payload tries to encrypt files if "linux_target_dir" and "windows_target_dir" inputs are empty.

We have empty "linux_target_dir" and "windows_target_dir" by default so it's important that ransomware payload doesn't try to encrypt files by default, without users' knowledge.

monkey/tests/unit_tests/infection_monkey/ransomware/test_ransomware_payload.py

@@ -163,6 +163,24 @@ def test_encryption_skipped_if_configured_false(
     assert hash_file(ransomware_target / TEST_KEYBOARD_TXT) == TEST_KEYBOARD_TXT_CLEARTEXT_SHA256
 
 
+def test_encryption_skipped_if_no_directory(
+    ransomware_payload_config, telemetry_messenger_spy, monkeypatch
+):
+    ransomware_payload_config["encryption"]["enabled"] = True
+    ransomware_payload_config["encryption"]["directories"]["linux_target_dir"] = ""
+    ransomware_payload_config["encryption"]["directories"]["windows_target_dir"] = ""
+
+    def _file_encryption_method_mock(*args, **kwargs):
+        raise Exception(
+            "Ransomware payload attempted to "
+            "encrypt files even though no directory was provided!"
+        )
+
+    ransomware_payload = RansomwarePayload(ransomware_payload_config, telemetry_messenger_spy)
+    monkeypatch.setattr(ransomware_payload, "_encrypt_files", _file_encryption_method_mock)
+    ransomware_payload.run_payload()
+
+
 def test_telemetry_success(ransomware_payload, telemetry_messenger_spy):
     ransomware_payload.run_payload()