Export session name in envvar NOX_CURRENT_SESSION (#641)

Author: ktbarrett

nox/sessions.py

@@ -724,6 +724,7 @@ def execute(self) -> Result:
             with cwd:
                 self._create_venv()
                 session = Session(self)
+                session.env["NOX_CURRENT_SESSION"] = session.name
                 self.func(session)
 
             # Nothing went wrong; return a success.

tests/test_sessions.py

@@ -900,6 +900,8 @@ def test__create_venv_unexpected_venv_backend(self):
     def make_runner_with_mock_venv(self):
         runner = self.make_runner()
         runner._create_venv = mock.Mock()
+        runner.venv = mock.create_autospec(nox.virtualenv.VirtualEnv)
+        runner.venv.env = {}
         return runner
 
     def test_execute_noop_success(self, caplog):
@@ -1017,6 +1019,23 @@ def func(session):
 
         assert result.status == nox.sessions.Status.FAILED
 
+    def test_execute_check_env(self):
+        runner = self.make_runner_with_mock_venv()
+
+        def func(session):
+            session.run(
+                sys.executable,
+                "-c",
+                'import os; raise SystemExit(0 if os.environ["NOX_CURRENT_SESSION"] =='
+                f" {session.name!r} else 0)",
+            )
+
+        runner.func = func
+
+        result = runner.execute()
+
+        assert result
+
 
 class TestResult:
     def test_init(self):