Pull out google login validation into validator class

util/config/validators/test/test_validate_google_login.py

@@ -0,0 +1,37 @@
+import pytest
+
+from httmock import urlmatch, HTTMock
+
+from util.config.validators import ConfigValidationException
+from util.config.validators.validate_google_login import GoogleLoginValidator
+
+@pytest.mark.parametrize('unvalidated_config', [
+  ({}),
+  ({'GOOGLE_LOGIN_CONFIG': {}}),
+  ({'GOOGLE_LOGIN_CONFIG': {'CLIENT_ID': 'foo'}}),
+  ({'GOOGLE_LOGIN_CONFIG': {'CLIENT_SECRET': 'foo'}}),
+])
+def test_validate_invalid_google_login_config(unvalidated_config):
+  validator = GoogleLoginValidator()
+
+  with pytest.raises(ConfigValidationException):
+    validator.validate(unvalidated_config, None, None)
+
+def test_validate_google_login():
+  url_hit = [False]
+  @urlmatch(netloc=r'www.googleapis.com', path='/oauth2/v3/token')
+  def handler(_, __):
+    url_hit[0] = True
+    return {'status_code': 200, 'content': ''}
+
+  validator = GoogleLoginValidator()
+
+  with HTTMock(handler):
+    validator.validate({
+      'GOOGLE_LOGIN_CONFIG': {
+        'CLIENT_ID': 'foo',
+        'CLIENT_SECRET': 'bar',
+      },
+    }, None, None)
+
+  assert url_hit[0]