Replicate problems with name discovery and dynamic versions

According to issue 3545 it seems that "name-discovery" happens, even
when the project already explicitly sets it.

This is related to parsing of dynamic versions (via `attr` directive),
which triggers the auto-discovery to obtain the value of `package_dir`.

The value of `package_dir` is used to find the path to the module
in `version = {"attr" = "module_name.attr_name"}`.

1 files changed, 34 insertions, 0 deletions

diff --git a/setuptools/tests/test_config_discovery.py b/setuptools/tests/test_config_discovery.py
index f6c114af..85b64b31 100644
--- a/setuptools/tests/test_config_discovery.py
+++ b/setuptools/tests/test_config_discovery.py
@@ -517,6 +517,40 @@ def test_name_discovery_doesnt_break_cli(tmpdir_cwd):
     assert dist.get_name() == "pkg"
 
 
+def test_preserve_explicit_name_with_dynamic_version(tmpdir_cwd, monkeypatch):
+    """According to #3545 it seems that ``name`` discovery is running,
+    even when the project already explicitly sets it.
+    This seems to be related to parsing of dynamic versions (via ``attr`` directive),
+    which requires the auto-discovery of ``package_dir``.
+    """
+    files = {
+        "src": {
+            "pkg": {"__init__.py": "__version__ = 42\n"},
+        },
+        "pyproject.toml": DALS("""
+            [project]
+            name = "myproj"  # purposefully different from package name
+            dynamic = ["version"]
+            [tool.setuptools.dynamic]
+            version = {"attr" = "pkg.__version__"}
+            """)
+    }
+    jaraco.path.build(files)
+    dist = Distribution({})
+    orig_analyse_name = dist.set_defaults.analyse_name
+
+    def spy_analyse_name():
+        # We can check if name discovery was triggered by ensuring the original
+        # name remains instead of the package name.
+        orig_analyse_name()
+        assert dist.get_name() == "myproj"
+
+    monkeypatch.setattr(dist.set_defaults, "analyse_name", spy_analyse_name)
+    dist.parse_config_files()
+    assert dist.get_version() == "42"
+    assert set(dist.packages) == {"pkg"}
+
+
 def _populate_project_dir(root, files, options):
     # NOTE: Currently pypa/build will refuse to build the project if no
     # `pyproject.toml` or `setup.py` is found. So it is impossible to do