ci: improve pytest doc

docs/en/contribute/esp-idf-tests-with-pytest.rst

@@ -272,6 +272,27 @@ This code example is taken from :idf_file:`pytest_esp_eth.py <components/esp_eth
 
 This flaky marker means that if the test function failed, the test case would rerun for a maximum of 3 times with 5 seconds delay.
 
+Mark Known Failure Cases
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Sometimes a test couldn't pass for the following reasons:
+
+- Has a bug
+- Success ratio too low because of environment issue, such as network issue. Retry couldn't help
+
+Now you may mark this test case with marker `xfail <https://docs.pytest.org/en/latest/how-to/skipping.html#xfail-mark-test-functions-as-expected-to-fail>`__ with a user-friendly readable reason.
+
+This code example is taken from :idf_file:`pytest_panic.py <tools/test_apps/system/panic/pytest_panic.py>`
+
+.. code:: python
+
+
+   @pytest.mark.xfail('config.getvalue("target") == "esp32s2"', reason='raised IllegalInstruction instead')
+   def test_cache_error(dut: PanicTestDut, config: str, test_func_name: str) -> None:
+
+This marker means that if the test would be a known failure one on esp32s2.
+
+
 Run the Tests in CI
 -------------------
 
@@ -368,6 +389,44 @@ We’re using two types of custom markers, target markers which indicate that th
 
 You can add new markers by adding one line under the ``${IDF_PATH}/pytest.ini`` ``markers =`` section. The grammar should be: ``<marker_name>: <marker_description>``
 
+Generate JUnit Report
+~~~~~~~~~~~~~~~~~~~~~
+
+You can call pytest with ``--junitxml <filepath>`` to generate the JUnit report. In ESP-IDF, the test case name would be unified as "<target>.<config>.<function_name>". 
+
+Skip Auto Flash Binary
+~~~~~~~~~~~~~~~~~~~~~~
+
+Skipping auto-flash binary everytime would be useful when you're debugging your test script.
+
+You can call pytest with ``--skip-autoflash y`` to achieve it.
+
+Record Statistics
+~~~~~~~~~~~~~~~~~
+
+Sometimes you may need to record some statistics while running the tests, like the performance test statistics.
+
+You can use `record_xml_attribute <https://docs.pytest.org/en/latest/how-to/output.html?highlight=junit#record-xml-attribute>`__ fixture in your test script, and the statistics would be recorded as attributes in the JUnit report.
+
+Logging System
+~~~~~~~~~~~~~~
+
+Sometimes you may need to add some extra logging lines while running the test cases.
+
+You can use `python logging module <https://docs.python.org/3/library/logging.html>`__ to achieve this.
+
+Known Limitations and Workarounds
+---------------------------------
+
+Avoid Using ``Thread`` for Performance Test
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+``pytest-embedded`` is using some threads internally to help gather all stdout to the pexpect process. Due to the limitation of `Global Interpreter Lock <https://en.wikipedia.org/wiki/Global_interpreter_lock>`__, if you're using threads to do performance tests, these threads would block each other and there would be great performance loss.
+
+**workaround**
+
+Use `Process <https://docs.python.org/3/library/multiprocessing.html#the-process-class>`__ instead, the APIs should be almost the same as ``Thread``.
+
 Further Readings
 ----------------
 

pytest.ini

@@ -3,10 +3,12 @@
 python_files = pytest_*.py
 
 # ignore PytestExperimentalApiWarning for record_xml_attribute
+# set traceback to "short" to prevent the overwhelming tracebacks
 addopts =
   -s
   --embedded-services esp,idf
   -W ignore::_pytest.warning_types.PytestExperimentalApiWarning
+  --tb short
 
 markers =
   esp32: support esp32 target