Ensure that when building sdists, subpackages with Python files (but …

…not necessarily an __init__.py file) will be included.

poetry/masonry/builders/sdist.py

@@ -237,7 +237,7 @@ def find_nearest_pkg(rel_path):
             if from_top_level == ".":
                 continue
 
-            is_subpkg = "__init__.py" in filenames
+            is_subpkg = any([filename.endswith(".py") for filename in filenames])
             if is_subpkg:
                 subpkg_paths.add(from_top_level)
                 parts = from_top_level.split(os.sep)

poetry/masonry/utils/package_include.py

@@ -12,7 +12,6 @@ def __init__(self, base, include, formats=None, source=None):
             base = base / source
 
         super(PackageInclude, self).__init__(base, include, formats=formats)
-
         self.check_elements()
 
     @property
@@ -35,6 +34,8 @@ def refresh(self):  # type: () -> PackageInclude
         return self.check_elements()
 
     def check_elements(self):  # type: () -> PackageInclude
+        root = self._elements[0]
+
         if not self._elements:
             raise ValueError(
                 "{} does not contain any element".format(self._base / self._include)
@@ -44,20 +45,24 @@ def check_elements(self):  # type: () -> PackageInclude
             # Probably glob
             self._is_package = True
 
-            # Packages no longer need an __init__.py in python3
-            root = self._elements[0]
-            if root.name == "__init__.py":
-                pass
+            # Packages no longer need an __init__.py in python3, but there must
+            # at least be one .py file for it to be considered a package
+            if not any([element.suffix == ".py" for element in self._elements]):
+                raise ValueError("{} is not a package.".format(root.name))
 
             self._package = root.parent.name
         else:
-            if self._elements[0].is_dir():
+            if root.is_dir():
                 # If it's a directory, we include everything inside it
-                self._package = self._elements[0].name
-                self._elements = sorted(list(self._elements[0].glob("**/*")))
+                self._package = root.name
+                self._elements = sorted(list(root.glob("**/*")))
+
+                if not any([element.suffix == ".py" for element in self._elements]):
+                    raise ValueError("{} is not a package.".format(root.name))
+
                 self._is_package = True
             else:
-                self._package = self._elements[0].stem
+                self._package = root.stem
                 self._is_module = True
 
         return self

tests/masonry/builders/test_complete.py

@@ -265,6 +265,7 @@ def test_complete_no_vcs():
         "my_package/sub_pkg1/__init__.py",
         "my_package/sub_pkg2/__init__.py",
         "my_package/sub_pkg2/data2/data.json",
+        "my_package/sub_pkg3/foo.py",
         "my_package-1.2.3.dist-info/entry_points.txt",
         "my_package-1.2.3.dist-info/LICENSE",
         "my_package-1.2.3.dist-info/WHEEL",

tests/masonry/builders/test_sdist.py

@@ -124,6 +124,7 @@ def test_make_setup():
         "my_package",
         "my_package.sub_pkg1",
         "my_package.sub_pkg2",
+        "my_package.sub_pkg3",
     ]
     assert ns["install_requires"] == ["cachy[msgpack]>=0.2.0,<0.3.0", "cleo>=0.6,<0.7"]
     assert ns["entry_points"] == {
@@ -178,6 +179,7 @@ def test_find_files_to_add():
             Path("my_package/sub_pkg1/__init__.py"),
             Path("my_package/sub_pkg2/__init__.py"),
             Path("my_package/sub_pkg2/data2/data.json"),
+            Path("my_package/sub_pkg3/foo.py"),
             Path("pyproject.toml"),
         ]
     )
@@ -213,7 +215,12 @@ def test_find_packages():
     pkg_dir, packages, pkg_data = builder.find_packages(include)
 
     assert pkg_dir is None
-    assert packages == ["my_package", "my_package.sub_pkg1", "my_package.sub_pkg2"]
+    assert packages == [
+        "my_package",
+        "my_package.sub_pkg1",
+        "my_package.sub_pkg2",
+        "my_package.sub_pkg3",
+    ]
     assert pkg_data == {
         "": ["*"],
         "my_package": ["data1/*"],

tests/masonry/utils/test_package_include.py

@@ -1,3 +1,5 @@
+import pytest
+
 from poetry.masonry.utils.package_include import PackageInclude
 from poetry.utils._compat import Path
 
@@ -16,6 +18,8 @@ def test_package_include_with_multiple_dirs():
         with_includes / "extra_package/some_dir",
         with_includes / "extra_package/some_dir/foo.py",
         with_includes / "extra_package/some_dir/quux.py",
+        with_includes / "not_a_python_pkg",
+        with_includes / "not_a_python_pkg/baz.txt",
     ]
 
 
@@ -30,3 +34,10 @@ def test_package_include_with_nested_dir():
         with_includes / "extra_package/some_dir/foo.py",
         with_includes / "extra_package/some_dir/quux.py",
     ]
+
+
+def test_package_include_with_no_python_files_in_dir():
+    with pytest.raises(ValueError) as e:
+        PackageInclude(base=with_includes, include="not_a_python_pkg")
+
+    assert str(e.value) == "not_a_python_pkg is not a package."