added per-key traitlets and test for extra_env

Author: Rishab87

jupyter_server/serverapp.py

@@ -1488,10 +1488,18 @@ def _default_allow_remote(self) -> bool:
         """
         ),
     )
+
     terminado_settings = Dict(
-        Union([List(), Unicode()]),
+        per_key_traits={
+            "shell_command": Union(
+                [List(), Unicode()], help="The shell command to execute in the terminal."
+            ),
+            "extra_env": Dict(
+                Unicode(), help="Extra environment variables to set in the terminal."
+            ),
+        },
         config=True,
-        help=_i18n('Supply overrides for terminado. Currently only supports "shell_command".'),
+        help=_i18n("Supply overrides for terminado."),
     )
 
     cookie_options = Dict(

tests/test_terminal.py

@@ -297,6 +297,17 @@ def test_shell_command_override(
         assert app.web_app.settings["terminal_manager"].shell_command == expected_shell
 
 
+def test_terminal_extra_env_override(jp_configurable_serverapp):
+    config = Config({"ServerApp": {"terminado_settings": {"extra_env": {"PS1": "jupyter> "}}}})
+
+    app = jp_configurable_serverapp(config=config)
+    terminado_settings = getattr(app, "terminado_settings", {})
+
+    assert "extra_env" in terminado_settings
+    assert "PS1" in terminado_settings["extra_env"]
+    assert terminado_settings["extra_env"]["PS1"] == "jupyter> "
+
+
 def test_importing_shims():
     with warnings.catch_warnings():
         warnings.simplefilter("ignore")