tests: add get_requires_for_build_wheel

setuptools/pep517.py

@@ -21,7 +21,13 @@ def _run_setup(setup_script='setup.py'): #
     exec(compile(code, __file__, 'exec'))
 
 
+def fix_config(config_settings):
+    config_settings = config_settings or {}
+    config_settings.setdefault('--global-option', [])
+    return config_settings
+
 def get_build_requires(config_settings):
+    config_settings = fix_config(config_settings)
     requirements = ['setuptools', 'wheel']
     dist.skip_install_eggs = True
 
@@ -38,10 +44,12 @@ def get_build_requires(config_settings):
 
 
 def get_requires_for_build_wheel(config_settings=None):
+    config_settings = fix_config(config_settings)
     return get_build_requires(config_settings)
 
 
 def get_requires_for_build_sdist(config_settings=None):
+    config_settings = fix_config(config_settings)
     return get_build_requires(config_settings)
 
 
@@ -51,6 +59,7 @@ def prepare_metadata_for_build_wheel(metadata_directory, config_settings=None):
 
 def build_wheel(wheel_directory, config_settings=None,
                 metadata_directory=None):
+    config_settings = fix_config(config_settings)
     wheel_directory = os.path.abspath(wheel_directory)
     sys.argv = sys.argv[:1] + ['bdist_wheel'] + \
         config_settings["--global-option"]
@@ -61,6 +70,7 @@ def build_wheel(wheel_directory, config_settings=None,
 
 
 def build_sdist(sdist_directory, config_settings=None):
+    config_settings = fix_config(config_settings)
     sdist_directory = os.path.abspath(sdist_directory)
     sys.argv = sys.argv[:1] + ['sdist'] + \
         config_settings["--global-option"]

setuptools/tests/test_pep517.py

@@ -6,7 +6,9 @@ import os
 # a concurrent.futures backport for testing
 pytest.importorskip('concurrent.futures')
 
+from contextlib import contextmanager
 from importlib import import_module
+from tempfile import mkdtemp
 from concurrent.futures import ProcessPoolExecutor
 from .files import build_files
 from .textwrap import DALS
@@ -24,10 +26,10 @@ class BuildBackend(object):
     def __getattr__(self, name):
         """Handles aribrary function invokations on the build backend."""
 
-        def method(**kw):
+        def method(*args, **kw):
             return self.pool.submit(
                 BuildBackendCaller(self.cwd, self.env, self.backend_name),
-                (name, kw)).result()
+                (name, args, kw)).result()
 
         return method
 
@@ -38,21 +40,33 @@ class BuildBackendCaller(object):
         self.env = env
         self.backend_name = backend_name
 
-    def __getattr__(self, name):
+    def __call__(self, info):
         """Handles aribrary function invokations on the build backend."""
         os.chdir(self.cwd)
         os.environ.update(self.env)
-        return getattr(import_module(self.backend_name), name)
+        name, args, kw = info
+        return getattr(import_module(self.backend_name), name)(*args, **kw)
+
+
+@contextmanager
+def enter_directory(dir, val=None):
+    original_dir = os.getcwd()
+    os.chdir(dir)
+    yield val
+    os.chdir(original_dir)
 
 
 @pytest.fixture
 def build_backend():
+    tmpdir = mkdtemp()
+    with enter_directory(tmpdir):
         setup_script = DALS("""
         from setuptools import setup
 
         setup(
             name='foo',
             py_modules=['hello'],
+            setup_requires=['test-package'],
             entry_points={'console_scripts': ['hi = hello.run']},
             zip_safe=False,
         )
@@ -66,4 +80,10 @@ def build_backend():
                 """)
         })
 
-    return BuildBackend(cwd='.')    
+    return enter_directory(tmpdir, BuildBackend(cwd='.'))
+
+
+def test_get_requires_for_build_wheel(build_backend):
+    with build_backend as b:
+        assert list(sorted(b.get_requires_for_build_wheel())) == \
+            list(sorted(['test-package', 'setuptools', 'wheel']))