dash_process_server test: back to original working dir after test

Author: alexcjohnson

tests/unit/test_app_runners.py

@@ -26,10 +26,14 @@ def test_threaded_server_smoke(dash_thread_server):
     sys.version_info < (3,), reason="requires python3 for process testing"
 )
 def test_process_server_smoke(dash_process_server):
+    cwd = os.getcwd()
     this_dir = os.path.dirname(__file__)
     assets_dir = os.path.abspath(os.path.join(this_dir, "..", "assets"))
-    os.chdir(assets_dir)
-    dash_process_server("simple_app")
-    r = requests.get(dash_process_server.url)
-    assert r.status_code == 200, "the server is reachable"
-    assert 'id="react-entry-point"' in r.text, "the entrypoint is present"
+    try:
+        os.chdir(assets_dir)
+        dash_process_server("simple_app")
+        r = requests.get(dash_process_server.url)
+        assert r.status_code == 200, "the server is reachable"
+        assert 'id="react-entry-point"' in r.text, "the entrypoint is present"
+    finally:
+        os.chdir(cwd)