Add setuptools command to generate setup.py

This change introduces `setuptools setupfile` command that generates
a `setup.py` file for the project.

Resolves: python-poetry#761

docs/docs/cli.md

@@ -484,3 +484,16 @@ poetry env remove test-O3eWbxRl-py3.7
 !!!note
 
     If your remove the currently activated virtualenv, it will be automatically deactivated.
+
+## setuptools
+
+The `setuptools` command groups sub commands to management of setuptools assets.
+
+### setuptools setupfile
+
+The `setuptools setupfile` command generates a `setup.py` file to be used by
+ `setuptools`.
+
+```bash
+poetry setuptools setupfile
+```

poetry/console/application.py

@@ -3,6 +3,7 @@
 from cleo import Application as BaseApplication
 
 from poetry import __version__
+from poetry.console.commands.setuptools.setuptools import SetuptoolsCommand
 
 from .commands import AboutCommand
 from .commands import AddCommand
@@ -31,6 +32,8 @@
 
 from .commands.self import SelfCommand
 
+from .commands.setuptools import SetupFileCommand
+
 from .config import ApplicationConfig
 
 from .commands.env import EnvCommand
@@ -94,6 +97,9 @@ def get_default_commands(self):  # type: () -> list
         # Env command
         commands += [EnvCommand()]
 
+        # Setuptools commands
+        commands += [SetuptoolsCommand()]
+
         # Self commands
         commands += [SelfCommand()]
 

poetry/console/commands/setuptools/__init__.py

@@ -0,0 +1 @@
+from .setupfile import SetupFileCommand

poetry/console/commands/setuptools/setupfile.py

@@ -0,0 +1,27 @@
+from clikit.io import NullIO
+
+from poetry.masonry.builders import SdistBuilder
+from poetry.utils._compat import Path
+from poetry.utils.env import NullEnv
+from ..command import Command
+
+
+class SetupFileCommand(Command):
+    """
+    Generate a setuptools compatible <comment>setup.py</comment>
+
+    setupfile
+    """
+
+    def handle(self):
+        try:
+            setupfile = Path(self.poetry.file.parent, "setup.py")
+            self.line("<info>Writing to <comment>{}</comment></info>".format(setupfile))
+            builder = SdistBuilder(self.poetry, NullEnv(), NullIO())
+            setupfile.write_bytes(builder.build_setup())
+        except Exception as e:
+            self.line("<error>{}</error>".format(e))
+            self.line("<error>Failed to write <comment>setup.py</comment>.</error>")
+            return 1
+
+        return 0

poetry/console/commands/setuptools/setuptools.py

@@ -0,0 +1,15 @@
+from ..command import Command
+from poetry.console.commands.setuptools import SetupFileCommand
+
+
+class SetuptoolsCommand(Command):
+    """
+    Manage setuptools assets for this project.
+
+    setuptools
+    """
+
+    commands = [SetupFileCommand()]
+
+    def handle(self):  # type: () -> int
+        return self.call("help", self._config.name)

tests/console/commands/setuptools/test_setupfile.py

@@ -0,0 +1,37 @@
+import shutil
+import tempfile
+
+import pytest
+from cleo.testers import CommandTester
+
+from poetry.poetry import Poetry
+from poetry.utils._compat import Path
+from tests.test_poetry import fixtures_dir
+
+
+@pytest.fixture
+def tmp_dir():
+    dir_ = tempfile.mkdtemp(prefix="poetry_")
+    yield dir_
+    shutil.rmtree(dir_)
+
+
+@pytest.fixture
+def poetry(repo, tmp_dir):
+    project_dir = Path(tmp_dir, "sample_project")
+    shutil.copytree(str(fixtures_dir / "simple_project"), str(project_dir))
+    yield Poetry.create(project_dir)
+    shutil.rmtree(str(project_dir), ignore_errors=True)
+
+
+def test_setupfile(app):
+    command = app.find("setuptools setupfile")
+    setupfile = Path(app.poetry.file.parent, "setup.py")
+
+    tester = CommandTester(command)
+    tester.execute()
+
+    assert setupfile.is_file()
+
+    expected = "Writing to {}\n".format(setupfile)
+    assert expected == tester.io.fetch_output()