Include test example. Update docs. Improve makefile

.pre-commit-config.yaml

@@ -1,24 +1,25 @@
 # See https://pre-commit.com for more information
 # See https://pre-commit.com/hooks.html for more hooks
-fail_fast: true
+fail_fast: false
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v3.2.0
+    rev: v4.5.0
     hooks:
     -   id: trailing-whitespace
         exclude: .*\.(md|json)
     -   id: end-of-file-fixer
         exclude: .*\.(json)
     -   id: check-yaml
+    -   id: check-json
     -   id: check-added-large-files
         args: [--maxkb=5120]  # 2 MB
 -   repo: https://github.com/psf/black
-    rev: 22.10.0
+    rev: 23.11.0
     hooks:
     -   id: black
         name: Formatting
 -   repo: https://github.com/pycqa/isort
-    rev: 5.10.1
+    rev: 5.12.0
     hooks:
       - id: isort
         name: Import order

Makefile

@@ -8,8 +8,12 @@ VENV_BIN=$(VENV_DIR)/bin
 venv:
 	@echo making venv at $(VENV_DIR)
 	@python -m venv $(VENV_DIR)
-	@$(VENV_PYTHON) -m pip install --upgrade pip wheel pre-commit
+	@$(VENV_PYTHON) -m pip install --upgrade pip setuptools wheel build pre-commit
 
 install: venv
 	@$(VENV_PYTHON) -m pip install --upgrade -e '.[dev]'
+	@$(VENV_PYTHON) -m pre_commit autoupdate
 	@$(VENV_PYTHON) -m pre_commit install
+
+build: install
+	@$(VENV_PYTHON) -m build

README.org

@@ -21,7 +21,7 @@ This worked example of a repo might help.
   dependencies with pip.
 - You can make CLI entry points that act like normal programs
 - You can share your code with others, or include it as a dependency in other projects.
--
+
 * So what are these files?
 ** convenience boilerplate
 #+begin_src
@@ -30,23 +30,26 @@ Makefile
 .pre-commit-config.yaml
 README.org
 #+end_src
-These files are optional.
+These files are optional: they are not required as far as /python/ is
+concerned.  They are conveniences for the developer that I have come around
+over the years to converging on.  I develop almost exclusively on linux
+(distro largely agnostic) and macOS.
 
-Using the lovely [[https://gitignore.io][gitignore.io]] collection of recommended ignores, I've populated
+- Using the lovely [[https://gitignore.io][gitignore.io]] collection of recommended ignores, I've populated
 a =.gitignore= for python and common editors.
 
-If you like to automate the creation of venvs and installation and whatnot with
+- If you like to automate the creation of venvs and installation and whatnot with
 =make=, as I do, then the included =Makefile= may be useful.
 
-Automatic code formatting with =black= and =isort= can be accomplished with =.pre-commit-config.yaml=
+- Automatic code formatting with =black= and =isort= can be accomplished with =.pre-commit-config.yaml=
 if [[https://pre-commit.com][pre-commit]] is used.
 
-And this file is =Readme.org=; choose a markup language of your preference.
+- And this file is =Readme.org=; choose a markup language of your preference.
 ** package files
 #+begin_src
 ├── pyproject.toml
 ├── template
-│   ├── cli.py
+│   ├── __main__.py
 │   └── __init__.py
 #+end_src
 
@@ -59,5 +62,32 @@ adoption of PEP517/517 by =setuptools=, though, you can ram it all into
 =pyproject.toml=.
 
 =template/= is the directory of the python package.  The name of the package is
-=template=, it has two modules =__init__= and =cli=, and =cli= has one function
-=main=, which is configured as the entry point, and simply prints ="Hello, world!"=.
+=template=, it has two modules =__init__= and =__main__=, and =__main__= has
+one function =main=, which is configured as the entry point, and simply prints
+="Hello,world!"=.
+
+- =__init__.py= flags the directory =template/= as a python package.  You need
+  to have this file in any package (read: directory) or sub-package.
+- =__main__.py= permits callers to invoke your code with =python -m template=;
+  when that is done, the =__main__.py= module is executed.  Consequently, it
+  contains an =if __name__ == "__main__"= test, which calls the same callable
+  (the function =main()=) that the entrypoint specified in =pyproject.toml=
+  does.
+
+  Add as many other modules, packages, etc. as you like under =template/=.
+** tests
+#+begin_src
+├── tests
+│   ├── __init__.py
+│   └── test_template.py
+#+end_src
+
+=pytest= is my preferred testing framework for python.  It's listed as a
+development dependency in =pyproject.toml=.
+
+- tests live in a directory called =tests=
+- invoking =./venv/bin/pytest ./tests= runs all python files inside tests whose
+  filenames start with =test_=.
+- each function inside those files whose name begins with =test_= is treated as
+  an independent unit test and is run.
+- see [[https://nedbatchelder.com/text/test3.html][ned batchelder's excellent pytest primer]] for more detail.

pyproject.toml

@@ -28,4 +28,4 @@ dynamic = ["version"]
 dev = ["pre-commit","pytest"]
 
 [project.scripts]
-template = "template.cli:main"
+template = "template.__main__:main"

template/__main__.py

@@ -0,0 +1,8 @@
+def main():
+    print("Hello, world!")
+
+
+if __name__ == "__main__":
+    """This test, at module level, permits the use of
+    `python -m template` to invoke whatever follows."""
+    main()

template/cli.py

@@ -1,2 +0,0 @@
-def main():
-    print("Hello, world!")

tests/test_template.py

@@ -0,0 +1,7 @@
+import template
+
+
+def test_template():
+    # assert that the call to the function succeeds (but since it's just a
+    # print, it returns None)
+    assert template.__main__.main() is None