Using posargs to pass tests as arguments to tests nox session (#4334)

* Using posargs to pass tests as arguments to  nox session

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>

* style: pre-commit fixes

* Adding info to docs

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>

* style: pre-commit fixes

---------

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>
Co-authored-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Arjun Verma <arjunverma.oc@gmail.com>

CONTRIBUTING.md

@@ -183,6 +183,11 @@ If you want to check integration tests as well as unit tests, type
 ```bash
 nox -s tests
 ```
+or, alternatively, you can use posargs to pass the path to the test to `nox`. For example:
+
+```bash
+nox -s tests -- tests/unit/test_plotting/test_quick_plot.py::TestQuickPlot::test_simple_ode_model
+```
 
 When you commit anything to PyBaMM, these checks will also be run automatically (see [infrastructure](#infrastructure)).
 

noxfile.py

@@ -266,7 +266,10 @@ def run_tests(session):
     set_environment_variables(PYBAMM_ENV, session=session)
     session.install("setuptools", silent=False)
     session.install("-e", ".[all,dev,jax]", silent=False)
-    session.run("python", "-m", "pytest", "-m", "unit or integration")
+    specific_test_files = session.posargs if session.posargs else []
+    session.run(
+        "python", "-m", "pytest", *specific_test_files, "-m", "unit or integration"
+    )
 
 
 @nox.session(name="docs")