Fix regression in stub-only package (PEP-561) support

Signed-off-by: oleg.hoefling <oleg.hoefling@gmail.com>

poetry/masonry/utils/package_include.py

@@ -33,6 +33,21 @@ def refresh(self):  # type: () -> PackageInclude
 
         return self.check_elements()
 
+    def is_stub_only(self):  # type: () -> bool
+        # returns `True` if this a PEP 561 stub-only package,
+        # see [PEP 561](https://www.python.org/dev/peps/pep-0561/#stub-only-packages)
+        return self.package.endswith("-stubs") and all(
+            el.suffix == ".pyi"
+            or (el.parent.name == self.package and el.name == "py.typed")
+            for el in self.elements
+            if el.is_file()
+        )
+
+    def has_modules(self):  # type: () -> bool
+        # 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
+        return any(element.suffix == ".py" for element in self.elements)
+
     def check_elements(self):  # type: () -> PackageInclude
         if not self._elements:
             raise ValueError(
@@ -43,20 +58,18 @@ def check_elements(self):  # type: () -> PackageInclude
         if len(self._elements) > 1:
             # Probably glob
             self._is_package = True
+            self._package = root.parent.name
 
-            # 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]):
+            if not self.is_stub_only() and not self.has_modules():
                 raise ValueError("{} is not a package.".format(root.name))
 
-            self._package = root.parent.name
         else:
             if root.is_dir():
                 # If it's a directory, we include everything inside it
                 self._package = root.name
                 self._elements = sorted(list(root.glob("**/*")))
 
-                if not any([element.suffix == ".py" for element in self._elements]):
+                if not self.is_stub_only() and not self.has_modules():
                     raise ValueError("{} is not a package.".format(root.name))
 
                 self._is_package = True

tests/masonry/builders/fixtures/pep_561_stub_only/pkg-stubs/module.pyi

@@ -0,0 +1,4 @@
+"""Example module"""
+from typing import Tuple
+
+version_info = Tuple[int, int, int]

tests/masonry/builders/fixtures/pep_561_stub_only/pyproject.toml

@@ -0,0 +1,14 @@
+[tool.poetry]
+name = "pep-561-stubs"
+version = "0.1"
+description = "PEP 561 stub package example"
+authors = [
+    "Oleg Höfling <oleg.hoefling@gmail.com>"
+]
+license = "MIT"
+packages = [
+    {include = "pkg-stubs"}
+]
+
+[tool.poetry.dependencies]
+python = "^3.6"

tests/masonry/builders/fixtures/pep_561_stub_only_partial/pkg-stubs/module.pyi

@@ -0,0 +1,4 @@
+"""Example module"""
+from typing import Tuple
+
+version_info = Tuple[int, int, int]

tests/masonry/builders/fixtures/pep_561_stub_only_partial/pkg-stubs/py.typed

@@ -0,0 +1 @@
+partial

tests/masonry/builders/fixtures/pep_561_stub_only_partial/pyproject.toml

@@ -0,0 +1,14 @@
+[tool.poetry]
+name = "pep-561-stubs"
+version = "0.1"
+description = "PEP 561 stub package example with the py.typed marker file"
+authors = [
+    "Oleg Höfling <oleg.hoefling@gmail.com>"
+]
+license = "MIT"
+packages = [
+    {include = "pkg-stubs"}
+]
+
+[tool.poetry.dependencies]
+python = "^3.6"

tests/masonry/builders/fixtures/pep_561_stub_only_src/pyproject.toml

@@ -0,0 +1,14 @@
+[tool.poetry]
+name = "pep-561-stubs"
+version = "0.1"
+description = "PEP 561 stub package example with an src layout"
+authors = [
+    "Oleg Höfling <oleg.hoefling@gmail.com>"
+]
+license = "MIT"
+packages = [
+    {include = "pkg-stubs", from = "src"}
+]
+
+[tool.poetry.dependencies]
+python = "^3.6"

tests/masonry/builders/fixtures/pep_561_stub_only_src/src/pkg-stubs/module.pyi

@@ -0,0 +1,4 @@
+"""Example module"""
+from typing import Tuple
+
+version_info = Tuple[int, int, int]

tests/masonry/builders/test_sdist.py

@@ -488,3 +488,21 @@ def test_excluded_subpackage():
     exec(compile(setup_ast, filename="setup.py", mode="exec"), ns)
 
     assert ns["packages"] == ["example"]
+
+
+def test_sdist_package_pep_561_stub_only():
+    root = fixtures_dir / "pep_561_stub_only"
+    poetry = Factory().create_poetry(root)
+
+    builder = SdistBuilder(poetry, NullEnv(), NullIO())
+    builder.build()
+
+    sdist = root / "dist" / "pep-561-stubs-0.1.tar.gz"
+
+    assert sdist.exists()
+
+    with tarfile.open(str(sdist), "r") as tar:
+        names = tar.getnames()
+        assert "pep-561-stubs-0.1/pkg-stubs/__init__.pyi" in names
+        assert "pep-561-stubs-0.1/pkg-stubs/module.pyi" in names
+        assert "pep-561-stubs-0.1/pkg-stubs/subpkg/__init__.pyi" in names

tests/masonry/builders/test_wheel.py

@@ -162,3 +162,33 @@ def test_dist_info_file_permissions():
             z.getinfo("my_package-1.2.3.dist-info/entry_points.txt").external_attr
             == 0o644 << 16
         )
+
+
+@pytest.mark.parametrize(
+    "package",
+    ["pep_561_stub_only", "pep_561_stub_only_partial", "pep_561_stub_only_src"],
+)
+def test_wheel_package_pep_561_stub_only(package):
+    root = fixtures_dir / package
+    WheelBuilder.make(Factory().create_poetry(root), NullEnv(), NullIO())
+
+    whl = root / "dist" / "pep_561_stubs-0.1-py3-none-any.whl"
+
+    assert whl.exists()
+
+    with zipfile.ZipFile(str(whl)) as z:
+        assert "pkg-stubs/__init__.pyi" in z.namelist()
+        assert "pkg-stubs/module.pyi" in z.namelist()
+        assert "pkg-stubs/subpkg/__init__.pyi" in z.namelist()
+
+
+def test_wheel_package_pep_561_stub_only_includes_typed_marker():
+    root = fixtures_dir / "pep_561_stub_only_partial"
+    WheelBuilder.make(Factory().create_poetry(root), NullEnv(), NullIO())
+
+    whl = root / "dist" / "pep_561_stubs-0.1-py3-none-any.whl"
+
+    assert whl.exists()
+
+    with zipfile.ZipFile(str(whl)) as z:
+        assert "pkg-stubs/py.typed" in z.namelist()

tests/masonry/utils/fixtures/pep_561_stub_only/bad/module.pyi

@@ -0,0 +1,5 @@
+"""Example module"""
+from typing import Tuple
+
+
+version_info = Tuple[int, int, int]

tests/masonry/utils/fixtures/pep_561_stub_only/good-stubs/module.pyi

@@ -0,0 +1,5 @@
+"""Example module"""
+from typing import Tuple
+
+
+version_info = Tuple[int, int, int]

tests/masonry/utils/test_package_include.py

@@ -50,3 +50,20 @@ def test_package_include_with_non_existent_directory():
     err_str = str(with_includes / "not_a_dir") + " does not contain any element"
 
     assert str(e.value) == err_str
+
+
+def test_pep_561_stub_only_package_good_name_suffix():
+    pkg_include = PackageInclude(
+        base=fixtures_dir / "pep_561_stub_only", include="good-stubs"
+    )
+    assert pkg_include.elements == [
+        fixtures_dir / "pep_561_stub_only/good-stubs/__init__.pyi",
+        fixtures_dir / "pep_561_stub_only/good-stubs/module.pyi",
+    ]
+
+
+def test_pep_561_stub_only_package_bad_name_suffix():
+    with pytest.raises(ValueError) as e:
+        PackageInclude(base=fixtures_dir / "pep_561_stub_only", include="bad")
+
+    assert str(e.value) == "bad is not a package."