Merge remote-tracking branch 'origin/all-pages-everywhere'

tests/app/test_template_previews.py

@@ -4,7 +4,7 @@ from functools import partial
 from unittest.mock import Mock
 from notifications_utils.template import LetterPreviewTemplate
 
-from app.template_previews import TemplatePreview
+from app.template_previews import TemplatePreview, get_page_count_for_letter
 
 
 @pytest.mark.parametrize('partial_call, expected_page_argument', [
@@ -65,3 +65,32 @@ def test_from_database_object_makes_request(
     headers = {'Authorization': 'Token my-secret-key'}
 
     request_mock.assert_called_once_with(expected_url, json=data, headers=headers)
+
+
+@pytest.mark.parametrize('template_type', [
+    'email', 'sms'
+])
+def test_page_count_returns_none_for_non_letter_templates(template_type):
+    assert get_page_count_for_letter({'template_type': template_type}) is None
+
+
+@pytest.mark.parametrize('partial_call, expected_template_preview_args', [
+    (
+        partial(get_page_count_for_letter),
+        ({'template_type': 'letter'}, None)
+    ),
+    (
+        partial(get_page_count_for_letter, values={'foo': 'bar'}),
+        ({'template_type': 'letter'}, {'foo': 'bar'})
+    ),
+])
+def test_page_count_unpacks_from_json_response(
+    mocker,
+    partial_call,
+    expected_template_preview_args,
+):
+    mock_template_preview = mocker.patch('app.template_previews.TemplatePreview.from_database_object')
+    mock_template_preview.return_value = (b'{"count": 99}', 200, {})
+
+    assert partial_call({'template_type': 'letter'}) == 99
+    mock_template_preview.assert_called_once_with(*expected_template_preview_args, filetype='json')