Abstract entrypoint support

pyproject.toml

@@ -6,11 +6,11 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "gather"
-version = "2024.1.5.2"
+version = "2024.1.5.3"
 description = "A gatherer"
 readme = "README.rst"
 authors = [{name = "Moshe Zadka", email = "[email protected]"}]
-dependencies = ["attrs", "incremental", "venusian"]
+dependencies = ["attrs", "incremental", "venusian", "toolz"]
 requires-python = ">=3.11"
 
 [project.optional-dependencies]

requirements-docs.txt

@@ -1,6 +1,6 @@
 #
-# This file is autogenerated by pip-compile with python 3.10
-# To update, run:
+# This file is autogenerated by pip-compile with Python 3.11
+# by the following command:
 #
 #    pip-compile --extra=docs --output-file=requirements-docs.txt pyproject.toml
 #
@@ -52,6 +52,8 @@ sphinxcontrib-qthelp==1.0.3
     # via sphinx
 sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
+toolz==0.12.0
+    # via gather (pyproject.toml)
 urllib3==1.26.9
     # via requests
 venusian==3.0.0

requirements-lint.txt

@@ -1,6 +1,6 @@
 #
-# This file is autogenerated by pip-compile with python 3.10
-# To update, run:
+# This file is autogenerated by pip-compile with Python 3.11
+# by the following command:
 #
 #    pip-compile --extra=lint --output-file=requirements-lint.txt pyproject.toml
 #
@@ -40,12 +40,10 @@ pyflakes==2.4.0
     # via flake8
 pylint==2.14.4
     # via gather (pyproject.toml)
-tomli==2.0.1
-    # via
-    #   black
-    #   pylint
 tomlkit==0.11.0
     # via pylint
+toolz==0.12.0
+    # via gather (pyproject.toml)
 venusian==3.0.0
     # via gather (pyproject.toml)
 wrapt==1.14.1

requirements-mypy.txt

@@ -1,6 +1,6 @@
 #
-# This file is autogenerated by pip-compile with python 3.10
-# To update, run:
+# This file is autogenerated by pip-compile with Python 3.11
+# by the following command:
 #
 #    pip-compile --extra=mypy --output-file=requirements-mypy.txt pyproject.toml
 #
@@ -12,8 +12,8 @@ mypy==0.961
     # via gather (pyproject.toml)
 mypy-extensions==0.4.3
     # via mypy
-tomli==2.0.1
-    # via mypy
+toolz==0.12.0
+    # via gather (pyproject.toml)
 typing-extensions==4.3.0
     # via mypy
 venusian==3.0.0

requirements-tests.txt

@@ -1,6 +1,6 @@
 #
-# This file is autogenerated by pip-compile with python 3.10
-# To update, run:
+# This file is autogenerated by pip-compile with Python 3.11
+# by the following command:
 #
 #    pip-compile --extra=tests --output-file=requirements-tests.txt pyproject.toml
 #
@@ -34,8 +34,8 @@ pyrsistent==0.18.1
     # via virtue
 six==1.16.0
     # via automat
-tomli==2.0.1
-    # via coverage
+toolz==0.12.0
+    # via gather (pyproject.toml)
 twisted==22.4.0
     # via virtue
 typing-extensions==4.3.0

src/gather/entry.py

@@ -0,0 +1,79 @@
+"""
+Abstractions for writing entrypoints
+"""
+
+from __future__ import annotations
+import functools
+import logging
+import runpy
+import sys
+from typing import Callable
+
+import attrs
+import toolz
+
+from . import commands as commandslib, api
+
+
+def dunder_main(globals_dct, command_data, logger=logging.getLogger()):
+    """
+    Call from ``__main__``
+    """
+    if globals_dct["__name__"] != "__main__":
+        raise ImportError("module cannot be imported", globals_dct["__name__"])
+    ch = logging.StreamHandler()
+    ch.setLevel(logging.INFO)
+    formatter = logging.Formatter("%(asctime)s:%(levelname)s:%(name)s:%(message)s")
+    ch.setFormatter(formatter)
+    logger.addHandler(ch)
+    commandslib.run_maybe_dry(
+        parser=commandslib.set_parser(collected=command_data.collector.collect()),
+        is_subcommand=globals_dct.get("IS_SUBCOMMAND", False),
+        prefix=command_data.prefix,
+        argv=sys.argv,
+    )
+
+
+def _noop(_ignored):  # pragma: no cover
+    pass
+
+
+@attrs.frozen
+class EntryData:
+    """
+    Data for the entry point.
+    """
+
+    prefix: str
+    collector: api.Collector
+    register: Callable
+    main_command: Callable[[], None]
+    sub_command: Callable[[], None]
+
+    @classmethod
+    def create(cls, package_name, prefix=None):
+        """
+        Create a new instance from package_name and prefix
+        """
+        if prefix is None:
+            prefix = package_name
+        collector = api.Collector()
+        register = commandslib.make_command_register(collector)
+        main_command = toolz.compose(
+            _noop,
+            functools.partial(
+                runpy.run_module,
+                package_name,
+                run_name="__main__",
+            ),
+        )
+        sub_command = functools.partial(
+            main_command, init_globals=dict(IS_SUBCOMMAND=True)
+        )
+        return cls(
+            prefix=prefix,
+            collector=collector,
+            register=register,
+            main_command=main_command,
+            sub_command=sub_command,
+        )

src/gather/tests/test_entry.py

@@ -0,0 +1,60 @@
+"""Test entrypoint"""
+import io
+import logging
+import unittest
+from unittest import mock
+
+from hamcrest import assert_that, calling, contains_string, equal_to, raises
+
+from .. import entry
+
+ENTRY_DATA = entry.EntryData.create("test_dunder_main")
+
+
+@ENTRY_DATA.register(name="fake")
+def _fake(args):
+    print("hello")
+
+
+class DunderMainTest(unittest.TestCase):
+
+    """Test dunder_main"""
+
+    def test_failed_import(self):
+        """
+        Function fails if the name is not __main__
+        """
+        assert_that(
+            calling(entry.dunder_main).with_args(
+                globals_dct=dict(__name__="some_name"),
+                command_data=None,
+                logger=None,
+            ),
+            raises(ImportError),
+        )
+
+    def test_run_command(self):
+        """
+        The fake command is called when the command line specifies it
+        """
+        logger = logging.Logger("nonce")
+        mock_output = mock.patch("sys.stdout", new=io.StringIO())
+        self.addCleanup(mock_output.stop)
+        fake_stdout = mock_output.start()
+        mock_args = mock.patch("sys.argv", new=[])
+        self.addCleanup(mock_args.stop)
+        fake_args = mock_args.start()
+        fake_args[:] = ["test", "fake"]
+        entry.dunder_main(
+            globals_dct=dict(__name__="__main__"),
+            logger=logger,
+            command_data=ENTRY_DATA,
+        )
+        assert_that(fake_stdout.getvalue(), contains_string("hello"))
+
+    def test_with_prefix(self):
+        """
+        An explicit prefix overrides the default
+        """
+        ed = entry.EntryData.create("test_dunder_main", prefix="thing")
+        assert_that(ed.prefix, equal_to("thing"))