Add test for ignore when setup.py present

Author: root

testing/test_collection.py

@@ -135,7 +135,7 @@ def test_foo():
 
 
 class TestCollectFS:
-    def test_build_conditional_ignore(self, pytester: Pytester) -> None:
+    def test_build_dirs_collected(self, pytester: Pytester) -> None:
         tmp_path = pytester.path
         ensure_file(tmp_path / "build" / "test_found.py")
         ensure_file(tmp_path / "dist" / "test_found.py")
@@ -146,6 +146,19 @@ def test_build_conditional_ignore(self, pytester: Pytester) -> None:
         s = result.stdout.str()
         assert "test_found" in s
 
+    def test_build_ignored_if_setuptools(self, pytester: Pytester) -> None:
+        tmp_path = pytester.path
+        ensure_file(tmp_path / "build" / "test_notfound.py")
+        ensure_file(tmp_path / "dist" / "test_notfound.py")
+        for x in tmp_path.rglob("test_*.py"):
+            x.write_text("def test_hello(): pass", encoding="utf-8")
+
+        ensure_file(tmp_path / "setup.py")
+
+        result = pytester.runpytest("--collect-only")
+        s = result.stdout.str()
+        assert "test_notfound" not in s
+
     def test_ignored_certain_directories(self, pytester: Pytester) -> None:
         tmp_path = pytester.path
         ensure_file(tmp_path / "_darcs" / "test_notfound.py")