list .venv when it exists

poetry/utils/env.py

@@ -367,11 +367,20 @@ def list(self, name=None):  # type: (Optional[str]) -> List[VirtualEnv]
         else:
             venv_path = Path(venv_path)
 
-        return [
+        env_list = [
             VirtualEnv(Path(p))
             for p in sorted(venv_path.glob("{}-py*".format(venv_name)))
         ]
 
+        venv = self._poetry.file.parent / ".venv"
+        if (
+            self._poetry.config.get("virtualenvs.in-project")
+            and venv.exists()
+            and venv.is_dir()
+        ):
+            env_list.insert(0, VirtualEnv(venv))
+        return env_list
+
     def remove(self, python):  # type: (str) -> Env
         venv_path = self._poetry.config.get("virtualenvs.path")
         if venv_path is None:

tests/console/commands/env/test_list.py

@@ -1,3 +1,5 @@
+import os
+
 import tomlkit
 
 from cleo.testers import CommandTester
@@ -56,3 +58,19 @@ def test_activated(app, tmp_dir):
     )
 
     assert expected == tester.io.fetch_output()
+
+
+def test_in_project_venv(app, tmpdir):
+    os.environ.pop("VIRTUAL_ENV", None)
+    app.poetry.config.merge({"virtualenvs": {"in-project": True}})
+
+    (app.poetry.file.parent / ".venv").mkdir(exist_ok=True)
+
+    command = app.find("env list")
+    tester = CommandTester(command)
+    tester.execute()
+
+    expected = ".venv (Activated)\n"
+
+    assert expected == tester.io.fetch_output()
+    (app.poetry.file.parent / ".venv").rmdir()