add resource leak detection fixture

CHANGES.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Add Renode device support.
+- Add opt-in resource leak detection fixture.
 
 ## 0.0.3
 

Documentation/usage.rst

@@ -229,6 +229,80 @@ Remaining tests are skipped if all retries fail.
        max_retries: 3      # reboot attempts before skipping remaining tests
        base_delay: 2.0     # seconds between retries (doubles each attempt)
 
+.. _resource-monitoring:
+
+Resource Monitoring
+===================
+
+Tests that request the ``resources`` fixture get their resource usage
+sampled before and after the test body. A delta that does not settle fails
+the test at teardown. The feature is disabled unless enabled here and needs
+``CONFIG_FS_PROCFS`` on the target.
+
+.. code-block:: yaml
+
+   config:
+     resources:
+       enabled: True
+       probes: [tasks, fds]         # default
+       settle_retries: 3            # re-samples while a delta remains
+       settle_delay: 1.0            # seconds between re-samples
+       heap_tolerance: 0            # bytes of heap growth tolerated
+       cpuload_max: 10              # percent, cpuload probe only
+
+Each probe runs one NSH command and compares the two samples:
+
+.. list-table::
+   :header-rows: 1
+
+   * - Probe
+     - Command
+     - Reports
+     - Requires
+   * - ``heap``
+     - ``free``
+     - ``used`` grew past ``heap_tolerance`` or ``nused`` grew, per heap
+     - ``CONFIG_NSH_DISABLE_FREE`` unset
+   * - ``tasks``
+     - ``ps``
+     - a task or thread present after the test but not before
+     - ``CONFIG_NSH_DISABLE_PS`` unset
+   * - ``fds``
+     - ``cat /proc/self/group/fd``
+     - a descriptor opened in the shell task group and not closed
+     - ``CONFIG_NSH_DISABLE_CAT`` unset
+   * - ``iob``
+     - ``cat /proc/iobinfo``
+     - fewer free network buffers
+     - ``CONFIG_MM_IOB``
+   * - ``mempool``
+     - ``cat /proc/mempool``
+     - ``nused`` grew, per pool
+     - ``CONFIG_MM_HEAP_MEMPOOL``
+   * - ``net``
+     - ``cat /proc/net/tcp``, ``cat /proc/net/udp``
+     - a new connection
+     - ``CONFIG_NET``
+   * - ``cpuload``
+     - ``cat /proc/cpuload``
+     - load above ``cpuload_max`` after the test
+     - ``CONFIG_SCHED_CPULOAD``
+
+A probe whose Kconfig requirements (including the matching
+``CONFIG_FS_PROCFS_EXCLUDE_*`` option) are not met on every product is
+dropped with a warning. The final delta is written to the device log and to
+the ``resources`` user property of the test report. Tests that crash or
+busy-loop are not checked.
+
+``tasks`` keys entries by TID and command name; set ``CONFIG_TASK_NAME_SIZE``
+above zero so a leaked task is reported by name rather than ``<noname>``.
+
+``heap`` is not a default: first-use allocations (stdio buffers, work
+queues) and shell state (environment variables, ``OLDPWD``) show up as
+growth, so it reports more than true leaks. Enable it per test with the
+``resources`` marker and a ``heap_tolerance`` that fits, or repeat the run
+with ``--loops`` and look for growth that recurs on every loop.
+
 Signal Handlers
 ===============
 

Documentation/writing-test-cases.rst

@@ -250,7 +250,26 @@ NTFC provides built-in fixtures and pytest marks for test development.
 
 Built-in Fixtures:
 
-TODO
+.. list-table::
+   :header-rows: 1
+
+   * - Fixture
+     - Purpose
+   * - ``core``
+     - Current core name, parametrized with ``--run_in_cores``
+   * - ``switch_to_core``
+     - Switch to the parametrized core in SMP mode and back afterwards
+   * - ``resources``
+     - Fail the test if resources are not released (see
+       :ref:`resource-monitoring`). List it after ``switch_to_core`` so
+       sampling happens on the switched core.
+
+.. code-block:: python
+
+   @pytest.mark.resources(probes=["heap", "tasks"], heap_tolerance=64)
+   def test_no_leak(resources):
+       ret = pytest.product.sendCommand("app", ["done"], timeout=15)
+       assert ret == 0
 
 Custom Fixtures:
 
@@ -300,6 +319,9 @@ Available Marks:
    * - ``@pytest.mark.skip()``
      - Skip test conditionally
      - ``@pytest.mark.skip(reason="not ready")``
+   * - ``@pytest.mark.resources()``
+     - Override resource monitor options for one test
+     - ``@pytest.mark.resources(probes=["heap"])``
    * - ``@pytest.mark.parser_binary()``
      - Discover and run test framework tests (cmocka / custom) as pytest items
      - ``@pytest.mark.parser_binary("bin", list_pattern=..., result_pattern=...)``

src/ntfc/envconfig.py

@@ -98,6 +98,28 @@ def heartbeat(self) -> Dict[str, Any]:
         # Merge with defaults
         return {**default_config, **heartbeat_cfg}
 
+    @property
+    def resources(self) -> Dict[str, Any]:
+        """Return resource monitoring configuration.
+
+        :return: Dictionary with keys: 'enabled' (bool), 'probes' (list),
+            'settle_retries' (int), 'settle_delay' (float),
+            'heap_tolerance' (int), 'cpuload_max' (float). Defaults to
+            disabled if not configured.
+        """
+        default_config = {
+            "enabled": False,
+            "probes": ["tasks", "fds"],
+            "settle_retries": 3,
+            "settle_delay": 1.0,
+            "heap_tolerance": 0,
+            "cpuload_max": 10,
+        }
+        config = self._cfg_values.get("config", {})
+        resources_cfg = config.get("resources", {})
+
+        return {**default_config, **resources_cfg}
+
     @property
     def recovery(self) -> Dict[str, Any]:
         """Return device recovery configuration.

src/ntfc/log/report.py

@@ -20,6 +20,7 @@
 
 """Report generation module for NTFC."""
 
+import copy
 import glob
 import html
 import os
@@ -118,22 +119,10 @@ def _split_xml_by_module(  # noqa: C901
             new_testsuite.set("time", str(time_total))
             new_testsuite.set("name", module_name)
 
-            # Add all test cases
+            # Add all test cases, including nested elements such as
+            # <properties><property/></properties>
             for testcase in testcases:
-                # Deep copy the testcase element
-                new_testcase = ElementTree.SubElement(
-                    new_testsuite, "testcase"
-                )
-                for attr, value in testcase.attrib.items():
-                    new_testcase.set(attr, value)
-
-                # Copy all child elements
-                for child in testcase:
-                    new_child = ElementTree.SubElement(new_testcase, child.tag)
-                    for attr, value in child.attrib.items():
-                        new_child.set(attr, value)
-                    if child.text:
-                        new_child.text = child.text
+                new_testsuite.append(copy.deepcopy(testcase))
 
             # Write per-module XML file
             output_file = os.path.join(

src/ntfc/pytest/configure.py

@@ -143,6 +143,8 @@ def pytest_configure(self, config: pytest.Config) -> None:
             "extra_opts: Additional parameters for testing "
             "(e.g., --run_in_cores=cpu1,cpu2)",
             "config_value_check: Validate complex configuration strings",
+            "resources: Override resource monitor options for one test "
+            "(e.g., probes=['heap'], heap_tolerance=64)",
         ]
 
         for m in markers:

src/ntfc/pytest/mypytest.py

@@ -42,6 +42,7 @@
 from .configure import PytestConfigPlugin
 from .gtest_plugin import GtestParserPlugin
 from .parsers import ParserPlugin
+from .resources_plugin import ResourcePlugin
 from .runner import RunnerPlugin
 from .signal_plugin import SignalPlugin
 
@@ -390,6 +391,9 @@ def runner(
         # run pytest with our custom test plugin
         runner = RunnerPlugin(nologs)
 
+        # resource leak detection fixture
+        resources = ResourcePlugin(self._config, pytest.products)
+
         # optional debug plugins (coredump collection)
         debug = get_debug_setup(pytest.products)
         self._ptconfig.set_restart_gdb(debug.restart_all_controllers)
@@ -400,7 +404,9 @@ def runner(
         try:
             # attach GDB controllers after the devices are up
             debug.start(pytest.result_dir)
-            return self._run(opt, [runner, collector, *debug.plugins])
+            return self._run(
+                opt, [runner, collector, resources, *debug.plugins]
+            )
         finally:
             debug.stop()
             self._device_stop()