Retrieve packages from top_level.txt when possible (#551)

The "packages" key that contains the list of modules part of the distribution
is used in the test imports section of the conda recipe.

It can be retrieved from setup.py.

When only pyproject.toml is present, this is usually not defined.
It can be added but depends on the build backend.

For project using setuptools, this information can be retrieved from the top_level.txt
file created in the .egg.info directory.

When "packages" isn't present, grayskull will use the name of the distribution,
but that might differ.

Co-authored-by: Marcelo Duarte Trevisani <marcelotrevisani@users.noreply.github.com>

grayskull/strategy/py_base.py

@@ -805,6 +805,16 @@ def get_sdist_metadata(
         for key in ("name", "version", "summary", "author"):
             metadata[key] = getattr(dist, key, None)
 
+    # "packages" refer to the modules you can import
+    # That might be different from the distribution name (PKG-INFO name)
+    # packages can be retrieved from setup.py but is usually not defined
+    # in pyproject.toml
+    # For setuptools, it is possible to get it from top_level.txt
+    if "packages" not in metadata or not metadata["packages"]:
+        top_level = list(Path(temp_folder).rglob("*.egg-info/top_level.txt"))
+        if top_level:
+            metadata["packages"] = top_level[0].read_text().split()
+
     return merge_setup_toml_metadata(metadata, pyproject_metadata)
 
 

tests/test_py_base.py

@@ -120,6 +120,38 @@ def test_get_sdist_metadata_toml_files_BLACK():
     ]
 
 
+def test_get_sdist_metadata_packages_top_level():
+    """Check that packages can be retrieved from top_level.txt"""
+    # This package only includes a pyproject.toml (no setup.py)
+    # As setuptools is used, the module name can be retrieved
+    # from top_level.txt in the sdist
+    pkg_name = "tangods-achtung"
+    pkg_name_nor = pkg_name.replace("-", "_")
+    pkg_ver = "0.11.1"
+    sdist_metadata = get_sdist_metadata(
+        f"https://pypi.io/packages/source/t/{pkg_name}/{pkg_name_nor}-{pkg_ver}.tar.gz",
+        Configuration(name=pkg_name, version=pkg_ver),
+    )
+    assert sdist_metadata["name"] == pkg_name
+    assert sdist_metadata["packages"] == ["achtung"]
+
+
+def test_get_sdist_metadata_no_top_level():
+    """Regression test when top_level.txt doesn't exist"""
+    # This package only includes a pyproject.toml (no setup.py)
+    # As hatchling is used, there is no top_level.txt file
+    pkg_name = "gidgetlab-kit"
+    pkg_name_nor = pkg_name.replace("-", "_")
+    pkg_ver = "0.7.2"
+    sdist_metadata = get_sdist_metadata(
+        f"https://pypi.io/packages/source/g/{pkg_name}/{pkg_name_nor}-{pkg_ver}.tar.gz",
+        Configuration(name=pkg_name, version=pkg_ver),
+    )
+    assert sdist_metadata["name"] == pkg_name
+    # No solution to retrieve packages for now
+    assert sdist_metadata.get("packages") is None
+
+
 def test_split_deps_without_comma():
     assert split_deps(">=1.8.0<3.0.0,!=2.0.1") == [">=1.8.0", "<3.0.0", "!=2.0.1"]