Extract tools/lib/test_server.py

This new module abstracts the setting up of a test
server for tests to run, pulling existing code from
casper and paving the way for API tests in the future.

tools/lib/test_server.py

@@ -0,0 +1,88 @@
+from __future__ import print_function
+
+import os
+import subprocess
+import sys
+import time
+
+from contextlib import contextmanager
+
+if False:
+    from typing import (Any, Iterator)
+
+try:
+    import django
+    import requests
+except ImportError as e:
+    print("ImportError: {}".format(e))
+    print("You need to run the Zulip tests inside a Zulip dev environment.")
+    print("If you are using Vagrant, you can `vagrant ssh` to enter the Vagrant guest.")
+    sys.exit(1)
+
+TOOLS_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+if TOOLS_DIR not in sys.path:
+    sys.path.insert(0, os.path.dirname(TOOLS_DIR))
+
+from zerver.lib.test_fixtures import is_template_database_current
+
+def set_up_django(external_host):
+    # type: (str) -> None
+    os.environ['EXTERNAL_HOST'] = external_host
+    os.environ["TORNADO_SERVER"] = "http://127.0.0.1:9983"
+    os.environ['DJANGO_SETTINGS_MODULE'] = 'zproject.test_settings'
+    django.setup()
+    os.environ['PYTHONUNBUFFERED'] = 'y'
+
+def assert_server_running(server):
+    # type: (subprocess.Popen) -> None
+    """Get the exit code of the server, or None if it is still running."""
+    if server.poll() is not None:
+        raise RuntimeError('Server died unexpectedly!')
+
+def server_is_up(server):
+    # type: (subprocess.Popen) -> bool
+    assert_server_running(server)
+    try:
+        # We could get a 501 error if the reverse proxy is up but the Django app isn't.
+        return requests.get('http://127.0.0.1:9981/accounts/home').status_code == 200
+    except:
+        return False
+
+@contextmanager
+def test_server_running(force=False, external_host='testserver', log=sys.stdout, dots=False):
+    # type: (bool, str, Any, bool) -> Iterator[None]
+    set_up_django(external_host)
+
+    generate_fixtures_command = ['tools/setup/generate-fixtures']
+    if not is_template_database_current():
+        generate_fixtures_command.append('--force')
+    subprocess.check_call(generate_fixtures_command)
+
+    # Run this not through the shell, so that we have the actual PID.
+    run_dev_server_command = ['tools/run-dev.py', '--test']
+    if force:
+        run_dev_server_command.append('--force')
+    server = subprocess.Popen(run_dev_server_command,
+                              stdout=log, stderr=log)
+
+    try:
+        # Wait for the server to start up.
+        sys.stdout.write('Waiting for test server')
+        while not server_is_up(server):
+            if dots:
+                sys.stdout.write('.')
+                sys.stdout.flush()
+            time.sleep(0.1)
+        sys.stdout.write('\n')
+
+        # DO OUR ACTUAL TESTING HERE!!!
+        yield
+
+    finally:
+        assert_server_running(server)
+        server.terminate()
+
+if __name__ == '__main__':
+    # The code below is for testing this module works
+    with test_server_running():
+        print('\n\n SERVER IS UP!\n\n')