Create enumecg executable

Currently the executable is a stub, and this commit merely sets up the
necessary modules, tests and documentation. The purpose is to allow
most of the functionality of the library (config options etc.) to from
command line.

docs/enumecglib.rst

@@ -42,8 +42,8 @@ values of the enum members are obvious in this style.
 
 .. _enumecg-definition-from-dict:
 
-Creating C++ enum from a dict
-.............................
+Creating C++ enum from a mapping
+................................
 
 This is a convenient method if the enum definitions are loaded from a
 file using general purpose serialization format like JSON or YAML.
@@ -371,6 +371,32 @@ enhanced enum type. The doxygen documentation of
 :ref:`enumecg-primary-enum` also includes the possible docstring of
 the Python enum definition.
 
+.. _enumecg-cli:
+
+Command line interface
+----------------------
+
+The :mod:`enumecg` module can be invoked as a command. Given a YAML
+file ``status.yaml``:
+
+.. literalinclude:: examples/status.yaml
+   :language: yaml
+
+The command line interface can use this file as an input to print the
+generated code to stdout.
+
+.. code-block:: console
+
+   $ enumecg status.yaml
+   ... # C++ definition printed to stdout
+
+The input file is a single YAML document containing an enum
+definition. See :ref:`enumecg-definition-from-dict` for the details of
+the schema.
+
+Invoking ``enumecg --help`` will list the supported options and
+arguments.
+
 .. _enumecg-high-level-api:
 
 High level API

docs/examples/status.yaml

@@ -0,0 +1,8 @@
+typename: Status
+members:
+- name: INITIALIZING
+  value: initializing
+- name: WAITING_FOR_INPUT
+  value: waitingForInput
+- name: BUSY
+  value: busy

python/enumecg/__main__.py

@@ -0,0 +1,2 @@
+from .cli import cli
+cli()

python/enumecg/cli.py

@@ -0,0 +1,30 @@
+"""
+EnumECG command line interface
+..............................
+
+Contains the command line interface to EnumECG. The entry point is
+:func:`cli()`.
+"""
+
+import click
+import yaml
+
+from . import generate
+
+@click.command()
+@click.argument("file", type=click.File())
+def cli(file):
+    """Generate C++ boilerplate for an Enhanced Enum definition
+
+    This executable is a part of the Enhanced Enum library. It is used
+    to generate the necessary C++ boilerplate to make an enumeration
+    type work with the library.
+
+    For a full discussion of the purpose of the library, and a
+    detailed description of the code generation process, see:
+
+        https://enhanced-enum.readthedocs.io/en/latest/
+
+    """
+    enum = yaml.safe_load(file)
+    click.echo(generate(enum))

python/setup.py

@@ -32,14 +32,24 @@ def get_package_dunder(name):
     license="MIT",
     url="https://github.com/jasujm/enhanced-enum",
     packages=["enumecg"],
+    entry_points={
+        "console_scripts": ["enumecg=enumecg.__main__:main"],
+    },
     package_data={"enumecg": ["templates/*.in", "templates/doxygen/*.in"]},
     classifiers=[
         "Programming Language :: Python :: 3",
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
     ],
     python_requires=">=3.7",
-    install_requires=["Jinja2>=2.10", "regex", "inflect>=3.0", "docstring-parser>=0.6"],
+    install_requires=[
+        "Jinja2>=2.10",
+        "regex",
+        "inflect>=3.0",
+        "docstring-parser>=0.6",
+        "PyYAML>=5.3",
+        "click>=7.1",
+    ],
 )
 
 # This is to bootstrap the build in case it is made with Enhanced Enum

python/tests/test_cli.py

@@ -0,0 +1,24 @@
+import yaml
+import pytest
+
+from click.testing import CliRunner
+
+from enumecg import generate
+from enumecg.cli import cli
+
+@pytest.fixture
+def cli_runner():
+    """Return CliRunner() to invoke enumecg CLI"""
+    return CliRunner()
+
+@pytest.fixture
+def enum_file(tmpdir, status_definition_dict):
+    """Return path to an YAML file containing serialized :const:`conftest.STATUS_DEFINITION_DICT`"""
+    p = tmpdir.join("enum.yaml")
+    with open(p, "w") as f:
+        yaml.dump(status_definition_dict, f)
+    return p
+
+def test_cli_should_generate_enum_definition_from_file(cli_runner, enum_file, status_definition):
+    result = cli_runner.invoke(cli, [str(enum_file)])
+    assert result.output == generate(status_definition) + "\n"

requirements-dev.txt

@@ -14,7 +14,7 @@ breathe==4.18.0           # via -r requirements-dev.in
 certifi==2020.4.5.1       # via requests
 cffi==1.14.0              # via cryptography
 chardet==3.0.4            # via requests
-click==7.1.2              # via black
+click==7.1.2              # via -c requirements.txt, black
 cryptography==2.9.2       # via secretstorage
 distlib==0.3.0            # via virtualenv
 docutils==0.16            # via breathe, readme-renderer, sphinx

requirements.in

@@ -2,3 +2,5 @@ jinja2>=2.10
 regex
 inflect>=3.0
 docstring-parser>=0.6
+PyYAML>=5.3
+click>=7.1

requirements.txt

@@ -4,10 +4,12 @@
 #
 #    pip-compile
 #
+click==7.1.2              # via -r requirements.in
 docstring-parser==0.7.1   # via -r requirements.in
 importlib-metadata==1.6.0  # via inflect
 inflect==4.1.0            # via -r requirements.in
 jinja2==2.11.2            # via -r requirements.in
 markupsafe==1.1.1         # via jinja2
+pyyaml==5.3.1             # via -r requirements.in
 regex==2020.4.4           # via -r requirements.in
 zipp==3.1.0               # via importlib-metadata