Migrate tox to nox (#673)

* Migrate tox to nox

* Update documentation fo tox->nox migration

* Apply suggestions from code review

Co-authored-by: Mateusz Nojek <matnojek@gmail.com>

Co-authored-by: Mateusz Nojek <matnojek@gmail.com>

CONTRIBUTING.rst

@@ -135,6 +135,11 @@ but most of it is located inside ``docs`` directory. The files are usually
 written using `reStructuredText format
 <https://www.writethedocs.org/guide/writing/reStructuredText/>`_ (.rst).
 
+To generate our documentation use ``nox`` tool that will create environment with required dependencies and generate
+the documentation. Documentation will be available under ``docs/_build/index.html`` path::
+
+    nox -s docs
+
 User manual
 '''''''''''
 
@@ -178,19 +183,23 @@ To run pytest tests navigate to directory with test files and run::
 Pytest will automatically discover all the tests, run them and display
 results. Make sure that tests do not fail.
 
-Together with Robocop installed with ``dev`` dependencies, you will be able to use
-`tox <https://github.com/tox-dev/tox>`_ tool (a CI task automation tool) which can run all tests on different environments.
-Currently two environments are available - one with Robot Framework v3.* and one with
-Robot Framework v4.*. You can simply run::
+Nox
+''''''''
+Robocop contains `nox <https://nox.thea.codes/en/stable/>`_ file for running the tests on all supported
+major Robot Framework versions and generating the coverage or docs. The nox tool will create the virtual environment and
+install required dependencies for you.
+
+Follow installation instruction from the ``nox`` documentation page. To execute Robocop tests run::
 
-    tox
+    nox
 
-and it will run all tests separately in these two environments and display the results.
+Run the following command to see all possible sessions (acting as environments or targets)::
 
-If you want to run tests for only one specific environment, you can choose between
-``rf3`` and ``rf4`` and run them with option ``-e``, e.g.::
+    nox --list
 
-    tox -e rf3
+You can select only one session per run. For example, to only run tests for ``Python==3.10`` and ``Robot Framework==3.*``::
+
+    nox --session "unit-3.10(robot_version='3')"
 
 Unit tests
 ''''''''''
@@ -251,6 +260,10 @@ and then::
 
     coverage html
 
+You can also use ``nox`` tool::
+
+    nox -s coverage
+
 HTML files will be generated - navigate to ``htmlcov`` directory and open ``index.html`` file.
 
 ::

noxfile.py

@@ -0,0 +1,49 @@
+import nox
+
+UNIT_TEST_PYTHON_VERSIONS = ["3.6", "3.7", "3.8", "3.9", "3.10"]
+nox.options.sessions = [
+    "unit",
+]
+
+
+def install_dev_deps(session, robot_major_ver):
+    session.install("-r", f"tests/packages/rf-stable{robot_major_ver}/requirements.txt")
+    session.install(".[dev]")
+
+
+def install_doc_deps(session, robot_major_ver):
+    session.install("-r", f"tests/packages/rf-stable{robot_major_ver}/requirements.txt")
+    session.install(".[doc]")
+
+
+@nox.session(python=UNIT_TEST_PYTHON_VERSIONS)
+@nox.parametrize("robot_version", ["3", "4", "5"])
+def unit(session, robot_version):
+    install_dev_deps(session, robot_version)
+    session.run("pytest", "--benchmark-skip", "tests")
+
+
+@nox.session()
+def coverage(session):
+    install_dev_deps(session, "5")
+    session.install("coverage")
+    session.run("coverage", "run", "-m", "pytest")
+    session.run("coverage", "html")
+
+
+@nox.session()
+def docs(session):
+    install_doc_deps(session, "5")
+    session.run("sphinx-build", "-b", "html", "docs", "docs/_build/")
+
+
+@nox.session()
+def benchmark(session):
+    install_dev_deps(session, "5")
+    session.run(
+        "pytest",
+        "--benchmark-only",
+        "--benchmark-enable",
+        "--benchmark-save=benchmark_results",
+        "--benchmark-save-data",
+    )

setup.py

@@ -67,7 +67,6 @@
             "pytest",
             "pytest-benchmark",
             "pyyaml",
-            "tox",
         ],
         "doc": [
             "furo",