Respect virtualenvs.in-project setting, if .venv is found in project folder

docs/docs/configuration.md

@@ -112,6 +112,10 @@ Defaults to `true`.
 Create the virtualenv inside the project's root directory.
 Defaults to `false`.
 
+If set to `true`, the virtualenv wil be created and expected in a folder named `.venv` within the root directory of the project.
+
+If not set explicitly, `poetry` will use the virtualenv from the `.venv` directory only if available.
+
 ### `virtualenvs.path`: string
 
 Directory where virtual environments will be created.

poetry/utils/env.py

@@ -346,10 +346,11 @@ def get(self, reload=False):  # type: (bool) -> Env
 
         if not in_venv or env is not None:
             # Checking if a local virtualenv exists
-            if (cwd / ".venv").exists() and (cwd / ".venv").is_dir():
-                venv = cwd / ".venv"
+            if self._poetry.config.get("virtualenvs.in-project") is not False:
+                if (cwd / ".venv").exists() and (cwd / ".venv").is_dir():
+                    venv = cwd / ".venv"
 
-                return VirtualEnv(venv)
+                    return VirtualEnv(venv)
 
             create_venv = self._poetry.config.get("virtualenvs.create", True)
 

tests/utils/test_env.py

@@ -74,17 +74,27 @@ def test_virtualenvs_with_spaces_in_their_path_work_as_expected(tmp_dir, manager
     assert venv.run("python", "-V", shell=True).startswith("Python")
 
 
-def test_env_get_in_project_venv(manager, poetry):
-    if "VIRTUAL_ENV" in os.environ:
-        del os.environ["VIRTUAL_ENV"]
-
-    (poetry.file.parent / ".venv").mkdir()
-
+@pytest.fixture
+def in_project_venv_dir(poetry):
+    os.environ.pop("VIRTUAL_ENV", None)
+    venv_dir = poetry.file.parent.joinpath(".venv")
+    venv_dir.mkdir()
+    try:
+        yield venv_dir
+    finally:
+        venv_dir.rmdir()
+
+
+@pytest.mark.parametrize("in_project", [True, False, None])
+def test_env_get_venv_with_venv_folder_present(
+    manager, poetry, in_project_venv_dir, in_project
+):
+    poetry.config.config["virtualenvs"]["in-project"] = in_project
     venv = manager.get()
-
-    assert venv.path == poetry.file.parent / ".venv"
-
-    shutil.rmtree(str(venv.path))
+    if in_project is False:
+        assert venv.path != in_project_venv_dir
+    else:
+        assert venv.path == in_project_venv_dir
 
 
 def build_venv(path, executable=None):  # type: (Union[Path,str], Optional[str]) -> ()