From 9fc5b4816a743f133387949e7a5392b7215393dd Mon Sep 17 00:00:00 2001
From: Alexander Hess <alexander@webartifex.biz>
Date: Tue, 4 Aug 2020 00:09:29 +0200
Subject: [PATCH] Add a testing tool chain

- use pytest as the base, measure coverage with pytest-cov
  + configure coverage to include branches and specify source locations
  + configure pytest to enforce explicit markers
- add a package for the test suite under tests/
- add a `__version__` identifier at the package's root
  + it is dynamically assigned the version of the installed package
  + the version is PEP440 compliant and follows a strict subset of
    semantic versioning: x.y.z[.devN] where x, y, z, and N are all
    non-negative integers
  + add module with tests for the __version__
- add a nox session "test" that runs the test suite
- use flake8 to lint pytest for consistent style
---
 noxfile.py                          |  26 +++-
 poetry.lock                         | 202 +++++++++++++++++++++++++++-
 pyproject.toml                      |   6 +
 setup.cfg                           |  50 ++++++-
 src/urban_meal_delivery/__init__.py |   8 ++
 tests/__init__.py                   |   1 +
 tests/test_version.py               | 116 ++++++++++++++++
 7 files changed, 406 insertions(+), 3 deletions(-)
 create mode 100644 tests/__init__.py
 create mode 100644 tests/test_version.py

diff --git a/noxfile.py b/noxfile.py
index 683ab79..9b24133 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -14,8 +14,11 @@ MAIN_PYTHON = '3.8'
 # Keep the project is forward compatible.
 NEXT_PYTHON = '3.9'
 
+# Path to the test suite.
+PYTEST_LOCATION = 'tests/'
+
 # Paths with *.py files.
-SRC_LOCATIONS = 'noxfile.py', 'src/'
+SRC_LOCATIONS = 'noxfile.py', 'src/', PYTEST_LOCATION
 
 
 # Use a unified .cache/ folder for all tools.
@@ -70,6 +73,7 @@ def lint(session: Session) -> None:
         'flake8-annotations',
         'flake8-black',
         'flake8-expression-complexity',
+        'flake8-pytest-style',
         'mypy',
         'pylint',
         'wemake-python-styleguide',
@@ -96,7 +100,27 @@ def lint(session: Session) -> None:
 @nox.session(python=[MAIN_PYTHON, NEXT_PYTHON])
 def test(session: Session) -> None:
     """Test the code base."""
+    # Re-using an old environment is not so easy here as
+    # `poetry install --no-dev` removes previously installed packages.
+    # We keep things simple and forbid such usage.
+    if session.virtualenv.reuse_existing:
+        raise RuntimeError('The "test" session must be run with the "-r" option')
+
     _begin(session)
+    # Install only the non-develop dependencies
+    # and the testing tool chain.
+    session.run('poetry', 'install', '--no-dev', external=True)
+    _install_packages(session, 'pytest', 'pytest-cov')
+    # Interpret extra arguments as options for pytest.
+    args = session.posargs or (
+        '--cov',
+        '--no-cov-on-fail',
+        '--cov-branch',
+        '--cov-fail-under=100',
+        '--cov-report=term-missing:skip-covered',
+        PYTEST_LOCATION,
+    )
+    session.run('pytest', *args)
 
 
 @nox.session(name='pre-commit', python=MAIN_PYTHON, venv_backend='none')
diff --git a/poetry.lock b/poetry.lock
index 2c6ed11..f4a669c 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -49,6 +49,15 @@ lazy-object-proxy = ">=1.4.0,<1.5.0"
 six = ">=1.12,<2.0"
 wrapt = ">=1.11,<2.0"
 
+[[package]]
+category = "dev"
+description = "Atomic file writes."
+marker = "sys_platform == \"win32\""
+name = "atomicwrites"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+version = "1.4.0"
+
 [[package]]
 category = "dev"
 description = "Classes Without Boilerplate"
@@ -137,6 +146,17 @@ version = "4.2.1"
 [package.dependencies]
 colorama = "*"
 
+[[package]]
+category = "dev"
+description = "Code coverage measurement for Python"
+name = "coverage"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, <4"
+version = "5.2.1"
+
+[package.extras]
+toml = ["toml"]
+
 [[package]]
 category = "dev"
 description = "A utility for ensuring Google-style docstrings stay up to date with the source code."
@@ -341,6 +361,14 @@ version = ">=4.3.5,<5"
 [package.extras]
 test = ["pytest (>=4.0.2,<6)"]
 
+[[package]]
+category = "dev"
+description = "The package provides base classes and utils for flake8 plugin writing"
+name = "flake8-plugin-utils"
+optional = false
+python-versions = ">=3.6,<4.0"
+version = "1.3.0"
+
 [[package]]
 category = "dev"
 description = "Polyfill package for Flake8 plugins"
@@ -352,6 +380,17 @@ version = "1.0.2"
 [package.dependencies]
 flake8 = "*"
 
+[[package]]
+category = "dev"
+description = "A flake8 plugin checking common style issues or inconsistencies with pytest-based tests."
+name = "flake8-pytest-style"
+optional = false
+python-versions = ">=3.6,<4.0"
+version = "1.2.2"
+
+[package.dependencies]
+flake8-plugin-utils = ">=1.3.0,<2.0.0"
+
 [[package]]
 category = "dev"
 description = "Flake8 lint for quotes."
@@ -408,6 +447,14 @@ version = "3.1.7"
 [package.dependencies]
 gitdb = ">=4.0.1,<5"
 
+[[package]]
+category = "dev"
+description = "iniconfig: brain-dead simple config-ini parsing"
+name = "iniconfig"
+optional = false
+python-versions = "*"
+version = "1.0.1"
+
 [[package]]
 category = "dev"
 description = "A Python utility / library to sort Python imports."
@@ -438,6 +485,14 @@ optional = false
 python-versions = "*"
 version = "0.6.1"
 
+[[package]]
+category = "dev"
+description = "More routines for operating on iterables, beyond itertools"
+name = "more-itertools"
+optional = false
+python-versions = ">=3.5"
+version = "8.4.0"
+
 [[package]]
 category = "dev"
 description = "Optional static typing for Python"
@@ -479,6 +534,18 @@ virtualenv = ">=14.0.0"
 [package.extras]
 tox_to_nox = ["jinja2", "tox"]
 
+[[package]]
+category = "dev"
+description = "Core utilities for Python packages"
+name = "packaging"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+version = "20.4"
+
+[package.dependencies]
+pyparsing = ">=2.0.2"
+six = "*"
+
 [[package]]
 category = "dev"
 description = "Utility library for gitignore style pattern matching of file paths."
@@ -506,6 +573,17 @@ version = "0.9.1"
 [package.dependencies]
 flake8-polyfill = ">=1.0.2,<2"
 
+[[package]]
+category = "dev"
+description = "plugin and hook calling mechanisms for python"
+name = "pluggy"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+version = "0.13.1"
+
+[package.extras]
+dev = ["pre-commit", "tox"]
+
 [[package]]
 category = "dev"
 description = "library with cross-python path, ini-parsing, io, code, log facilities"
@@ -564,6 +642,52 @@ isort = ">=4.2.5,<5"
 mccabe = ">=0.6,<0.7"
 toml = ">=0.7.1"
 
+[[package]]
+category = "dev"
+description = "Python parsing module"
+name = "pyparsing"
+optional = false
+python-versions = ">=2.6, !=3.0.*, !=3.1.*, !=3.2.*"
+version = "2.4.7"
+
+[[package]]
+category = "dev"
+description = "pytest: simple powerful testing with Python"
+name = "pytest"
+optional = false
+python-versions = ">=3.5"
+version = "6.0.1"
+
+[package.dependencies]
+atomicwrites = ">=1.0"
+attrs = ">=17.4.0"
+colorama = "*"
+iniconfig = "*"
+more-itertools = ">=4.0.0"
+packaging = "*"
+pluggy = ">=0.12,<1.0"
+py = ">=1.8.2"
+toml = "*"
+
+[package.extras]
+checkqa_mypy = ["mypy (0.780)"]
+testing = ["argcomplete", "hypothesis (>=3.56)", "mock", "nose", "requests", "xmlschema"]
+
+[[package]]
+category = "dev"
+description = "Pytest plugin for measuring coverage."
+name = "pytest-cov"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
+version = "2.10.0"
+
+[package.dependencies]
+coverage = ">=4.4"
+pytest = ">=4.6"
+
+[package.extras]
+testing = ["fields", "hunter", "process-tests (2.0.2)", "six", "pytest-xdist", "virtualenv"]
+
 [[package]]
 category = "dev"
 description = "YAML parser and emitter for Python"
@@ -719,7 +843,7 @@ python-versions = "*"
 version = "1.12.1"
 
 [metadata]
-content-hash = "e69534c9133ef3fb975f33937c97711f69281a8ffb931097a7b9e4ae1132fa09"
+content-hash = "1a6ddbc4c05cb41329cbac4792210897f11dda8e8ba3aa7e814a4a0d0d9c4fa8"
 lock-version = "1.0"
 python-versions = "^3.8"
 
@@ -744,6 +868,10 @@ astroid = [
     {file = "astroid-2.4.2-py3-none-any.whl", hash = "sha256:bc58d83eb610252fd8de6363e39d4f1d0619c894b0ed24603b881c02e64c7386"},
     {file = "astroid-2.4.2.tar.gz", hash = "sha256:2f4078c2a41bf377eea06d71c9d2ba4eb8f6b1af2135bec27bbbb7d8f12bb703"},
 ]
+atomicwrites = [
+    {file = "atomicwrites-1.4.0-py2.py3-none-any.whl", hash = "sha256:6d1784dea7c0c8d4a5172b6c620f40b6e4cbfdf96d783691f2e1302a7b88e197"},
+    {file = "atomicwrites-1.4.0.tar.gz", hash = "sha256:ae70396ad1a434f9c7046fd2dd196fc04b12f9e91ffb859164193be8b6168a7a"},
+]
 attrs = [
     {file = "attrs-19.3.0-py2.py3-none-any.whl", hash = "sha256:08a96c641c3a74e44eb59afb61a24f2cb9f4d7188748e76ba4bb5edfa3cb7d1c"},
     {file = "attrs-19.3.0.tar.gz", hash = "sha256:f7b7ce16570fe9965acd6d30101a28f62fb4a7f9e926b3bbc9b61f8b04247e72"},
@@ -771,6 +899,42 @@ colorlog = [
     {file = "colorlog-4.2.1-py2.py3-none-any.whl", hash = "sha256:43597fd822ce705190fc997519342fdaaf44b9b47f896ece7aa153ed4b909c74"},
     {file = "colorlog-4.2.1.tar.gz", hash = "sha256:75e55822c3a3387d721579241e776de2cf089c9ef9528b1f09e8b04d403ad118"},
 ]
+coverage = [
+    {file = "coverage-5.2.1-cp27-cp27m-macosx_10_13_intel.whl", hash = "sha256:40f70f81be4d34f8d491e55936904db5c527b0711b2a46513641a5729783c2e4"},
+    {file = "coverage-5.2.1-cp27-cp27m-macosx_10_9_x86_64.whl", hash = "sha256:675192fca634f0df69af3493a48224f211f8db4e84452b08d5fcebb9167adb01"},
+    {file = "coverage-5.2.1-cp27-cp27m-manylinux1_i686.whl", hash = "sha256:2fcc8b58953d74d199a1a4d633df8146f0ac36c4e720b4a1997e9b6327af43a8"},
+    {file = "coverage-5.2.1-cp27-cp27m-manylinux1_x86_64.whl", hash = "sha256:64c4f340338c68c463f1b56e3f2f0423f7b17ba6c3febae80b81f0e093077f59"},
+    {file = "coverage-5.2.1-cp27-cp27m-win32.whl", hash = "sha256:52f185ffd3291196dc1aae506b42e178a592b0b60a8610b108e6ad892cfc1bb3"},
+    {file = "coverage-5.2.1-cp27-cp27m-win_amd64.whl", hash = "sha256:30bc103587e0d3df9e52cd9da1dd915265a22fad0b72afe54daf840c984b564f"},
+    {file = "coverage-5.2.1-cp27-cp27mu-manylinux1_i686.whl", hash = "sha256:9ea749fd447ce7fb1ac71f7616371f04054d969d412d37611716721931e36efd"},
+    {file = "coverage-5.2.1-cp27-cp27mu-manylinux1_x86_64.whl", hash = "sha256:ce7866f29d3025b5b34c2e944e66ebef0d92e4a4f2463f7266daa03a1332a651"},
+    {file = "coverage-5.2.1-cp35-cp35m-macosx_10_13_x86_64.whl", hash = "sha256:4869ab1c1ed33953bb2433ce7b894a28d724b7aa76c19b11e2878034a4e4680b"},
+    {file = "coverage-5.2.1-cp35-cp35m-manylinux1_i686.whl", hash = "sha256:a3ee9c793ffefe2944d3a2bd928a0e436cd0ac2d9e3723152d6fd5398838ce7d"},
+    {file = "coverage-5.2.1-cp35-cp35m-manylinux1_x86_64.whl", hash = "sha256:28f42dc5172ebdc32622a2c3f7ead1b836cdbf253569ae5673f499e35db0bac3"},
+    {file = "coverage-5.2.1-cp35-cp35m-win32.whl", hash = "sha256:e26c993bd4b220429d4ec8c1468eca445a4064a61c74ca08da7429af9bc53bb0"},
+    {file = "coverage-5.2.1-cp35-cp35m-win_amd64.whl", hash = "sha256:4186fc95c9febeab5681bc3248553d5ec8c2999b8424d4fc3a39c9cba5796962"},
+    {file = "coverage-5.2.1-cp36-cp36m-macosx_10_13_x86_64.whl", hash = "sha256:b360d8fd88d2bad01cb953d81fd2edd4be539df7bfec41e8753fe9f4456a5082"},
+    {file = "coverage-5.2.1-cp36-cp36m-manylinux1_i686.whl", hash = "sha256:1adb6be0dcef0cf9434619d3b892772fdb48e793300f9d762e480e043bd8e716"},
+    {file = "coverage-5.2.1-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:098a703d913be6fbd146a8c50cc76513d726b022d170e5e98dc56d958fd592fb"},
+    {file = "coverage-5.2.1-cp36-cp36m-win32.whl", hash = "sha256:962c44070c281d86398aeb8f64e1bf37816a4dfc6f4c0f114756b14fc575621d"},
+    {file = "coverage-5.2.1-cp36-cp36m-win_amd64.whl", hash = "sha256:b1ed2bdb27b4c9fc87058a1cb751c4df8752002143ed393899edb82b131e0546"},
+    {file = "coverage-5.2.1-cp37-cp37m-macosx_10_13_x86_64.whl", hash = "sha256:c890728a93fffd0407d7d37c1e6083ff3f9f211c83b4316fae3778417eab9811"},
+    {file = "coverage-5.2.1-cp37-cp37m-manylinux1_i686.whl", hash = "sha256:538f2fd5eb64366f37c97fdb3077d665fa946d2b6d95447622292f38407f9258"},
+    {file = "coverage-5.2.1-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:27ca5a2bc04d68f0776f2cdcb8bbd508bbe430a7bf9c02315cd05fb1d86d0034"},
+    {file = "coverage-5.2.1-cp37-cp37m-win32.whl", hash = "sha256:aab75d99f3f2874733946a7648ce87a50019eb90baef931698f96b76b6769a46"},
+    {file = "coverage-5.2.1-cp37-cp37m-win_amd64.whl", hash = "sha256:c2ff24df02a125b7b346c4c9078c8936da06964cc2d276292c357d64378158f8"},
+    {file = "coverage-5.2.1-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:304fbe451698373dc6653772c72c5d5e883a4aadaf20343592a7abb2e643dae0"},
+    {file = "coverage-5.2.1-cp38-cp38-manylinux1_i686.whl", hash = "sha256:c96472b8ca5dc135fb0aa62f79b033f02aa434fb03a8b190600a5ae4102df1fd"},
+    {file = "coverage-5.2.1-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:8505e614c983834239f865da2dd336dcf9d72776b951d5dfa5ac36b987726e1b"},
+    {file = "coverage-5.2.1-cp38-cp38-win32.whl", hash = "sha256:700997b77cfab016533b3e7dbc03b71d33ee4df1d79f2463a318ca0263fc29dd"},
+    {file = "coverage-5.2.1-cp38-cp38-win_amd64.whl", hash = "sha256:46794c815e56f1431c66d81943fa90721bb858375fb36e5903697d5eef88627d"},
+    {file = "coverage-5.2.1-cp39-cp39-macosx_10_13_x86_64.whl", hash = "sha256:16042dc7f8e632e0dcd5206a5095ebd18cb1d005f4c89694f7f8aafd96dd43a3"},
+    {file = "coverage-5.2.1-cp39-cp39-manylinux1_i686.whl", hash = "sha256:c1bbb628ed5192124889b51204de27c575b3ffc05a5a91307e7640eff1d48da4"},
+    {file = "coverage-5.2.1-cp39-cp39-manylinux1_x86_64.whl", hash = "sha256:4f6428b55d2916a69f8d6453e48a505c07b2245653b0aa9f0dee38785939f5e4"},
+    {file = "coverage-5.2.1-cp39-cp39-win32.whl", hash = "sha256:9e536783a5acee79a9b308be97d3952b662748c4037b6a24cbb339dc7ed8eb89"},
+    {file = "coverage-5.2.1-cp39-cp39-win_amd64.whl", hash = "sha256:b8f58c7db64d8f27078cbf2a4391af6aa4e4767cc08b37555c4ae064b8558d9b"},
+    {file = "coverage-5.2.1.tar.gz", hash = "sha256:a34cb28e0747ea15e82d13e14de606747e9e484fb28d63c999483f5d5188e89b"},
+]
 darglint = [
     {file = "darglint-1.5.2-py3-none-any.whl", hash = "sha256:049a98cf3aec8cf6ea344a863c68112d80b7f8de214459b5fa6853371f89c3e7"},
     {file = "darglint-1.5.2.tar.gz", hash = "sha256:6b9461f96694c2cf1d8edb1597a783fe6840953b0eb18cc6cc1e72a26f196d79"},
@@ -838,10 +1002,18 @@ flake8-isort = [
     {file = "flake8-isort-3.0.1.tar.gz", hash = "sha256:5d976da513cc390232ad5a9bb54aee8a092466a15f442d91dfc525834bee727a"},
     {file = "flake8_isort-3.0.1-py2.py3-none-any.whl", hash = "sha256:df1dd6dd73f6a8b128c9c783356627231783cccc82c13c6dc343d1a5a491699b"},
 ]
+flake8-plugin-utils = [
+    {file = "flake8-plugin-utils-1.3.0.tar.gz", hash = "sha256:965931e7c17a760915e38bb10dc60516b414ef8210e987252a8d73dcb196a5f5"},
+    {file = "flake8_plugin_utils-1.3.0-py3-none-any.whl", hash = "sha256:305461c4fbf94877bcc9ccf435771b135d72a40eefd92e70a4b5f761ca43b1c8"},
+]
 flake8-polyfill = [
     {file = "flake8-polyfill-1.0.2.tar.gz", hash = "sha256:e44b087597f6da52ec6393a709e7108b2905317d0c0b744cdca6208e670d8eda"},
     {file = "flake8_polyfill-1.0.2-py2.py3-none-any.whl", hash = "sha256:12be6a34ee3ab795b19ca73505e7b55826d5f6ad7230d31b18e106400169b9e9"},
 ]
+flake8-pytest-style = [
+    {file = "flake8-pytest-style-1.2.2.tar.gz", hash = "sha256:93830b18d961613a012061867b15b1434e433662197ec3a7594db8389637d5f9"},
+    {file = "flake8_pytest_style-1.2.2-py3-none-any.whl", hash = "sha256:63e93d10b9cca6c73309319e89e7b1a8d316c7d1f12407faca975c498192fde3"},
+]
 flake8-quotes = [
     {file = "flake8-quotes-2.1.2.tar.gz", hash = "sha256:c844c9592940c8926c60f00bc620808912ff2acd34923ab5338f3a5ca618a331"},
 ]
@@ -860,6 +1032,10 @@ gitpython = [
     {file = "GitPython-3.1.7-py3-none-any.whl", hash = "sha256:fa3b92da728a457dd75d62bb5f3eb2816d99a7fe6c67398e260637a40e3fafb5"},
     {file = "GitPython-3.1.7.tar.gz", hash = "sha256:2db287d71a284e22e5c2846042d0602465c7434d910406990d5b74df4afb0858"},
 ]
+iniconfig = [
+    {file = "iniconfig-1.0.1-py3-none-any.whl", hash = "sha256:80cf40c597eb564e86346103f609d74efce0f6b4d4f30ec8ce9e2c26411ba437"},
+    {file = "iniconfig-1.0.1.tar.gz", hash = "sha256:e5f92f89355a67de0595932a6c6c02ab4afddc6fcdc0bfc5becd0d60884d3f69"},
+]
 isort = [
     {file = "isort-4.3.21-py2.py3-none-any.whl", hash = "sha256:6e811fcb295968434526407adb8796944f1988c5b65e8139058f2014cbe100fd"},
     {file = "isort-4.3.21.tar.gz", hash = "sha256:54da7e92468955c4fceacd0c86bd0ec997b0e1ee80d97f67c35a78b719dccab1"},
@@ -891,6 +1067,10 @@ mccabe = [
     {file = "mccabe-0.6.1-py2.py3-none-any.whl", hash = "sha256:ab8a6258860da4b6677da4bd2fe5dc2c659cff31b3ee4f7f5d64e79735b80d42"},
     {file = "mccabe-0.6.1.tar.gz", hash = "sha256:dd8d182285a0fe56bace7f45b5e7d1a6ebcbf524e8f3bd87eb0f125271b8831f"},
 ]
+more-itertools = [
+    {file = "more-itertools-8.4.0.tar.gz", hash = "sha256:68c70cc7167bdf5c7c9d8f6954a7837089c6a36bf565383919bb595efb8a17e5"},
+    {file = "more_itertools-8.4.0-py3-none-any.whl", hash = "sha256:b78134b2063dd214000685165d81c154522c3ee0a1c0d4d113c80361c234c5a2"},
+]
 mypy = [
     {file = "mypy-0.782-cp35-cp35m-macosx_10_6_x86_64.whl", hash = "sha256:2c6cde8aa3426c1682d35190b59b71f661237d74b053822ea3d748e2c9578a7c"},
     {file = "mypy-0.782-cp35-cp35m-manylinux1_x86_64.whl", hash = "sha256:9c7a9a7ceb2871ba4bac1cf7217a7dd9ccd44c27c2950edbc6dc08530f32ad4e"},
@@ -915,6 +1095,10 @@ nox = [
     {file = "nox-2020.5.24-py3-none-any.whl", hash = "sha256:c4509621fead99473a1401870e680b0aadadce5c88440f0532863595176d64c1"},
     {file = "nox-2020.5.24.tar.gz", hash = "sha256:61a55705736a1a73efbd18d5b262a43d55a1176546e0eb28b29064cfcffe26c0"},
 ]
+packaging = [
+    {file = "packaging-20.4-py2.py3-none-any.whl", hash = "sha256:998416ba6962ae7fbd6596850b80e17859a5753ba17c32284f67bfff33784181"},
+    {file = "packaging-20.4.tar.gz", hash = "sha256:4357f74f47b9c12db93624a82154e9b120fa8293699949152b22065d556079f8"},
+]
 pathspec = [
     {file = "pathspec-0.8.0-py2.py3-none-any.whl", hash = "sha256:7d91249d21749788d07a2d0f94147accd8f845507400749ea19c1ec9054a12b0"},
     {file = "pathspec-0.8.0.tar.gz", hash = "sha256:da45173eb3a6f2a5a487efba21f050af2b41948be6ab52b6a1e3ff22bb8b7061"},
@@ -927,6 +1111,10 @@ pep8-naming = [
     {file = "pep8-naming-0.9.1.tar.gz", hash = "sha256:a33d38177056321a167decd6ba70b890856ba5025f0a8eca6a3eda607da93caf"},
     {file = "pep8_naming-0.9.1-py2.py3-none-any.whl", hash = "sha256:45f330db8fcfb0fba57458c77385e288e7a3be1d01e8ea4268263ef677ceea5f"},
 ]
+pluggy = [
+    {file = "pluggy-0.13.1-py2.py3-none-any.whl", hash = "sha256:966c145cd83c96502c3c3868f50408687b38434af77734af1e9ca461a4081d2d"},
+    {file = "pluggy-0.13.1.tar.gz", hash = "sha256:15b2acde666561e1298d71b523007ed7364de07029219b604cf808bfa1c765b0"},
+]
 py = [
     {file = "py-1.9.0-py2.py3-none-any.whl", hash = "sha256:366389d1db726cd2fcfc79732e75410e5fe4d31db13692115529d34069a043c2"},
     {file = "py-1.9.0.tar.gz", hash = "sha256:9ca6883ce56b4e8da7e79ac18787889fa5206c79dcc67fb065376cd2fe03f342"},
@@ -951,6 +1139,18 @@ pylint = [
     {file = "pylint-2.5.3-py3-none-any.whl", hash = "sha256:d0ece7d223fe422088b0e8f13fa0a1e8eb745ebffcb8ed53d3e95394b6101a1c"},
     {file = "pylint-2.5.3.tar.gz", hash = "sha256:7dd78437f2d8d019717dbf287772d0b2dbdfd13fc016aa7faa08d67bccc46adc"},
 ]
+pyparsing = [
+    {file = "pyparsing-2.4.7-py2.py3-none-any.whl", hash = "sha256:ef9d7589ef3c200abe66653d3f1ab1033c3c419ae9b9bdb1240a85b024efc88b"},
+    {file = "pyparsing-2.4.7.tar.gz", hash = "sha256:c203ec8783bf771a155b207279b9bccb8dea02d8f0c9e5f8ead507bc3246ecc1"},
+]
+pytest = [
+    {file = "pytest-6.0.1-py3-none-any.whl", hash = "sha256:8b6007800c53fdacd5a5c192203f4e531eb2a1540ad9c752e052ec0f7143dbad"},
+    {file = "pytest-6.0.1.tar.gz", hash = "sha256:85228d75db9f45e06e57ef9bf4429267f81ac7c0d742cc9ed63d09886a9fe6f4"},
+]
+pytest-cov = [
+    {file = "pytest-cov-2.10.0.tar.gz", hash = "sha256:1a629dc9f48e53512fcbfda6b07de490c374b0c83c55ff7a1720b3fccff0ac87"},
+    {file = "pytest_cov-2.10.0-py2.py3-none-any.whl", hash = "sha256:6e6d18092dce6fad667cd7020deed816f858ad3b49d5b5e2b1cc1c97a4dba65c"},
+]
 pyyaml = [
     {file = "PyYAML-5.3.1-cp27-cp27m-win32.whl", hash = "sha256:74809a57b329d6cc0fdccee6318f44b9b8649961fa73144a98735b0aaf029f1f"},
     {file = "PyYAML-5.3.1-cp27-cp27m-win_amd64.whl", hash = "sha256:240097ff019d7c70a4922b6869d8a86407758333f02203e0fc6ff79c5dcede76"},
diff --git a/pyproject.toml b/pyproject.toml
index b63b74f..c4934e0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,6 +41,12 @@ flake8 = "^3.8.3"
 flake8-annotations = "^2.3.0"
 flake8-black = "^0.2.1"
 flake8-expression-complexity = "^0.0.8"
+flake8-pytest-style = "^1.2.2"
 mypy = "^0.782"
 pylint = "^2.5.3"
 wemake-python-styleguide = "^0.14.1"  # flake8 plug-in
+
+# Test Suite
+packaging = "^20.4"  # used to test the packaged version
+pytest = "^6.0.1"
+pytest-cov = "^2.10.0"
diff --git a/setup.cfg b/setup.cfg
index 93815ad..59af783 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -2,6 +2,23 @@
 # black's settings are in pyproject.toml => [tool.black]
 
 
+[coverage:paths]
+source =
+    src/
+    */site-packages/
+
+[coverage:report]
+show_missing = true
+skip_covered = true
+skip_empty = true
+
+[coverage:run]
+branch = true
+data_file = .cache/coverage/data
+source =
+    urban_meal_delivery
+
+
 [flake8]
 # Include error classes only explicitly
 # to avoid forward compatibility issues.
@@ -57,6 +74,8 @@ select =
     BLK1, BLK9,
     # flake8-expression-complexity => not too many expressions at once
     ECE001,
+    # flake8-pytest-style => enforce a consistent style with pytest
+    PT0,
 
 # By default, flake8 ignores some errors.
 # Instead, do not ignore anything.
@@ -70,6 +89,10 @@ extend-ignore =
     E203, W503,
     # f-strings are ok.
     WPS305,
+    # Classes should not have to specify a base class.
+    WPS306,
+    # Putting logic into __init__.py files may be justified.
+    WPS412,
 
 per-file-ignores =
     noxfile.py:
@@ -79,6 +102,11 @@ per-file-ignores =
         WPS213,
         # No overuse of string constants (e.g., '--version').
         WPS226,
+    tests/*.py:
+        # `assert` statements are ok in the test suite.
+        S101,
+        # Shadowing outer scopes occurs naturally with mocks.
+        WPS442,
 
 # Explicitly set mccabe's maximum complexity to 10 as recommended by
 # Thomas McCabe, the inventor of the McCabe complexity, and the NIST.
@@ -106,6 +134,17 @@ docstring-convention = google
 # flake8-eradicate
 eradicate-aggressive = true
 
+# ==============================
+# flake8-pytest-style's settings
+# ==============================
+# Prefer @pytest.fixture over @pytest.fixture().
+pytest-fixture-no-parentheses = true
+# Prefer @pytest.mark.parametrize(['param1', 'param2'], [(1, 2), (3, 4)])
+# over @pytest.mark.parametrize(('param1', 'param2'), ([1, 2], [3, 4]))
+pytest-parametrize-names-type = list
+pytest-parametrize-values-row-type = tuple
+pytest-parametrize-values-type = list
+
 
 [isort]
 atomic = true
@@ -134,7 +173,7 @@ single_line_exclusions = typing
 [mypy]
 cache_dir = .cache/mypy
 
-[mypy-nox.*]
+[mypy-nox.*,packaging.*,pytest]
 ignore_missing_imports = true
 
 
@@ -165,6 +204,15 @@ disable =
     missing-class-docstring, missing-function-docstring, missing-module-docstring,
     # pyflakes
     undefined-variable, unused-import, unused-variable,
+    # wemake-python-styleguide
+    redefined-outer-name,
 
 [pylint.REPORTS]
 score = no
+
+
+[tool:pytest]
+addopts =
+    --strict-markers
+cache_dir = .cache/pytest
+console_output_style = count
diff --git a/src/urban_meal_delivery/__init__.py b/src/urban_meal_delivery/__init__.py
index 27023c3..d17278b 100644
--- a/src/urban_meal_delivery/__init__.py
+++ b/src/urban_meal_delivery/__init__.py
@@ -1 +1,9 @@
 """Source code for the urban-meal-delivery research project."""
+
+from importlib import metadata
+
+
+try:
+    __version__ = metadata.version(__name__)
+except metadata.PackageNotFoundError:  # pragma: no cover
+    __version__ = 'unknown'
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..606a650
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1 @@
+"""Test the urban-meal-delivery package."""
diff --git a/tests/test_version.py b/tests/test_version.py
new file mode 100644
index 0000000..e3bf23c
--- /dev/null
+++ b/tests/test_version.py
@@ -0,0 +1,116 @@
+"""Test the package's version identifier.
+
+This packaged version identifier must adhere to PEP440
+and a strict subset of semantic versioning:
+
+- version identifiers must follow the x.y.z format
+  where x.y.z are non-negative integers
+- non-final versions are only allowed with a .devN suffix
+  where N is also a non-negative integer
+"""
+
+import re
+
+import pytest
+from packaging import version as pkg_version
+from packaging.version import Version
+
+import urban_meal_delivery
+
+
+@pytest.fixture
+def parsed_version() -> str:
+    """The packaged version."""
+    return pkg_version.Version(urban_meal_delivery.__version__)  # noqa:WPS609
+
+
+class TestPEP404Compliance:
+    """Packaged version identifier is PEP440 compliant."""
+
+    # pylint:disable=no-self-use
+
+    def test_parsed_version_has_no_epoch(self, parsed_version: Version) -> None:
+        """PEP440 compliant subset of semantic versioning: no epoch."""
+        assert parsed_version.epoch == 0
+
+    def test_parsed_version_is_non_local(self, parsed_version: Version) -> None:
+        """PEP440 compliant subset of semantic versioning: no local version."""
+        assert parsed_version.local is None
+
+    def test_parsed_version_is_no_post_release(self, parsed_version: Version) -> None:
+        """PEP440 compliant subset of semantic versioning: no post releases."""
+        assert parsed_version.is_postrelease is False
+
+    def test_parsed_version_is_all_public(self, parsed_version: Version) -> None:
+        """PEP440 compliant subset of semantic versioning: all public parts."""
+        assert parsed_version.public == urban_meal_delivery.__version__  # noqa:WPS609
+
+
+class TestSemanticVersioning:
+    """Packaged version follows a strict subset of semantic versioning."""
+
+    # pylint:disable=no-self-use
+
+    version_pattern = re.compile(
+        r'^(0|([1-9]\d*))\.(0|([1-9]\d*))\.(0|([1-9]\d*))(\.dev(0|([1-9]\d*)))?$',
+    )
+
+    def test_version_is_semantic(self) -> None:
+        """Packaged version follows semantic versioning."""
+        result = self.version_pattern.fullmatch(
+            urban_meal_delivery.__version__,  # noqa:WPS609
+        )
+
+        assert result is not None
+
+    # The next two test cases are sanity checks to validate the version_pattern.
+
+    @pytest.mark.parametrize(
+        'version',
+        [
+            '0.1.0',
+            '1.0.0',
+            '1.2.3',
+            '1.23.456',
+            '123.4.56',
+            '10.11.12',
+            '1.2.3.dev0',
+            '1.2.3.dev1',
+            '1.2.3.dev10',
+        ],
+    )
+    def test_valid_semantic_versioning(self, version: str) -> None:
+        """Versions follow the x.y.z or x.y.z.devN format."""
+        result = self.version_pattern.fullmatch(version)
+
+        assert result is not None
+
+    @pytest.mark.parametrize(
+        'version',
+        [
+            '1',
+            '1.2',
+            '-1.2.3',
+            '01.2.3',
+            '1.02.3',
+            '1.2.03',
+            '1.2.3.4',
+            '1.2.3.abc',
+            '1.2.3-dev0',
+            '1.2.3+dev0',
+            '1.2.3.d0',
+            '1.2.3.develop0',
+            '1.2.3.dev-1',
+            '1.2.3.dev01',
+            '1.2.3..dev0',
+            '1-2-3',
+            '1,2,3',
+            '1..2.3',
+            '1.2..3',
+        ],
+    )
+    def test_invalid_semantic_versioning(self, version: str) -> None:
+        """Versions follow the x.y.z or x.y.z.devN format."""
+        result = self.version_pattern.fullmatch(version)
+
+        assert result is None