add template folder CRUD

* create template folder
* rename template folder
* get list of template folders for service (not nested/presented in any
  particular way)
* delete template folder

Also removed `lazy=dynamic` from the `template_folder.templates`
relationship. lazy=dynamic returns a query object (which you can then
filter further). We just want to return the entire fetched list, at
least for now.

tests/app/db.py

@@ -48,7 +48,8 @@ from app.models import (
     FactBilling,
     FactNotificationStatus,
     Complaint,
-    InvitedUser
+    InvitedUser,
+    TemplateFolder,
 )
 
 
@@ -690,3 +691,10 @@ def create_invited_user(service=None,
     invited_user = InvitedUser(**data)
     save_invited_user(invited_user)
     return invited_user
+
+
+def create_template_folder(service, name='foo', parent=None):
+    tf = TemplateFolder(name=name, service=service, parent=parent)
+    db.session.add(tf)
+    db.session.commit()
+    return tf

tests/app/template_folder/test_template_folder_rest.py

@@ -0,0 +1,178 @@
+import uuid
+
+import pytest
+
+from app.models import TemplateFolder
+
+from tests.app.db import create_service, create_template_folder
+
+
+def test_get_folders_for_service(admin_request, notify_db_session):
+    s1 = create_service(service_name='a')
+    s2 = create_service(service_name='b')
+
+    tf1 = create_template_folder(s1)
+    tf2 = create_template_folder(s1)
+
+    create_template_folder(s2)
+
+    resp = admin_request.get('template_folder.get_template_folders_for_service', service_id=s1.id)
+    assert set(resp.keys()) == {'template_folders'}
+    assert sorted(resp['template_folders'], key=lambda x: x['id']) == sorted([
+        {'id': str(tf1.id), 'name': 'foo', 'service_id': str(s1.id), 'parent_id': None},
+        {'id': str(tf2.id), 'name': 'foo', 'service_id': str(s1.id), 'parent_id': None},
+    ], key=lambda x: x['id'])
+
+
+def test_get_folders_for_service_with_no_folders(sample_service, admin_request):
+    resp = admin_request.get('template_folder.get_template_folders_for_service', service_id=sample_service.id)
+    assert resp == {'template_folders': []}
+
+
+@pytest.mark.parametrize('has_parent', [True, False])
+def test_create_template_folder(admin_request, sample_service, has_parent):
+    existing_folder = create_template_folder(sample_service)
+
+    parent_id = str(existing_folder.id) if has_parent else None
+
+    resp = admin_request.post(
+        'template_folder.create_template_folder',
+        service_id=sample_service.id,
+        _data={
+            'name': 'foo',
+            'parent_id': parent_id
+        },
+        _expected_status=201
+    )
+
+    assert resp['data']['name'] == 'foo'
+    assert resp['data']['service_id'] == str(sample_service.id)
+    assert resp['data']['parent_id'] == parent_id
+
+
+@pytest.mark.parametrize('missing_field', ['name', 'parent_id'])
+def test_create_template_folder_fails_if_missing_fields(admin_request, sample_service, missing_field):
+    data = {
+        'name': 'foo',
+        'parent_id': None
+    }
+    data.pop(missing_field)
+
+    resp = admin_request.post(
+        'template_folder.create_template_folder',
+        service_id=sample_service.id,
+        _data=data,
+        _expected_status=400
+    )
+
+    assert resp == {
+        'status_code': 400,
+        'errors': [
+            {'error': 'ValidationError', 'message': '{} is a required property'.format(missing_field)}
+        ]
+    }
+
+
+def test_create_template_folder_fails_if_unknown_parent_id(admin_request, sample_service):
+    # create existing folder
+    create_template_folder(sample_service)
+
+    resp = admin_request.post(
+        'template_folder.create_template_folder',
+        service_id=sample_service.id,
+        _data={'name': 'bar', 'parent_id': str(uuid.uuid4())},
+        _expected_status=400
+    )
+
+    assert resp['result'] == 'error'
+    assert resp['message'] == 'parent_id not found'
+
+
+def test_rename_template_folder(admin_request, sample_service):
+    existing_folder = create_template_folder(sample_service)
+
+    resp = admin_request.post(
+        'template_folder.rename_template_folder',
+        service_id=sample_service.id,
+        template_folder_id=existing_folder.id,
+        _data={
+            'name': 'bar'
+        }
+    )
+
+    assert resp['data']['name'] == 'bar'
+    assert existing_folder.name == 'bar'
+
+
+@pytest.mark.parametrize('data, err', [
+    ({}, 'name is a required property'),
+    ({'name': None}, 'name None is not of type string'),
+    ({'name': ''}, 'name  is too short'),
+])
+def test_rename_template_folder_fails_if_missing_name(admin_request, sample_service, data, err):
+    existing_folder = create_template_folder(sample_service)
+
+    resp = admin_request.post(
+        'template_folder.rename_template_folder',
+        service_id=sample_service.id,
+        template_folder_id=existing_folder.id,
+        _data=data,
+        _expected_status=400
+    )
+
+    assert resp == {
+        'status_code': 400,
+        'errors': [
+            {'error': 'ValidationError', 'message': err}
+        ]
+    }
+
+
+def test_delete_template_folder(admin_request, sample_service):
+    existing_folder = create_template_folder(sample_service)
+
+    admin_request.delete(
+        'template_folder.delete_template_folder',
+        service_id=sample_service.id,
+        template_folder_id=existing_folder.id,
+    )
+
+    assert TemplateFolder.query.all() == []
+
+
+def test_delete_template_folder_fails_if_folder_has_subfolders(admin_request, sample_service):
+    existing_folder = create_template_folder(sample_service)
+    existing_subfolder = create_template_folder(sample_service, parent=existing_folder)  # noqa
+
+    resp = admin_request.delete(
+        'template_folder.delete_template_folder',
+        service_id=sample_service.id,
+        template_folder_id=existing_folder.id,
+        _expected_status=400
+    )
+
+    assert resp == {
+        'result': 'error',
+        'message': 'Folder is not empty'
+    }
+
+    assert TemplateFolder.query.count() == 2
+
+
+def test_delete_template_folder_fails_if_folder_contains_templates(admin_request, sample_service, sample_template):
+    existing_folder = create_template_folder(sample_service)
+    sample_template.folder = existing_folder
+
+    resp = admin_request.delete(
+        'template_folder.delete_template_folder',
+        service_id=sample_service.id,
+        template_folder_id=existing_folder.id,
+        _expected_status=400
+    )
+
+    assert resp == {
+        'result': 'error',
+        'message': 'Folder is not empty'
+    }
+
+    assert TemplateFolder.query.count() == 1