Add preview endpoint and tests

tests/app/v2/template/test_post_template.py

@@ -0,0 +1,83 @@
+import pytest
+import uuid
+
+from flask import json
+
+from app.models import EMAIL_TYPE, SMS_TYPE, LETTER_TYPE
+from tests import create_authorization_header
+from tests.app.db import create_template
+
+valid_data = {
+    'personalisation': {'Name': 'Jo'}
+}
+
+
+@pytest.mark.parametrize("tmp_type", [EMAIL_TYPE, SMS_TYPE])
+def test_valid_post_template_returns_200(client, sample_service, tmp_type):
+    template = create_template(
+        sample_service,
+        template_type=tmp_type,
+        content='Dear ((Name)), Hello. Yours Truly, The Government.')
+
+    auth_header = create_authorization_header(service_id=sample_service.id)
+
+    response = client.post(
+        path='/v2/template/{}/preview'.format(template.id),
+        data=json.dumps(valid_data),
+        headers=[('Content-Type', 'application/json'), auth_header])
+
+    assert response.status_code == 200
+
+    resp_json = json.loads(response.get_data(as_text=True))
+
+    assert resp_json['id'] == str(template.id)
+    assert 'v2/template/{}/preview'.format(template.id) in resp_json['uri']
+    assert 'Dear {}'.format(valid_data['personalisation']['Name']) in resp_json['content']['body']
+
+
+@pytest.mark.parametrize("tmp_type", [EMAIL_TYPE, SMS_TYPE])
+def test_invalid_post_template_returns_400(client, sample_service, tmp_type):
+    template = create_template(
+        sample_service,
+        template_type=tmp_type,
+        content='Dear ((Name)), Hello ((Missing)). Yours Truly, The Government.')
+
+    auth_header = create_authorization_header(service_id=sample_service.id)
+
+    response = client.post(
+        path='/v2/template/{}/preview'.format(template.id),
+        data=json.dumps(valid_data),
+        headers=[('Content-Type', 'application/json'), auth_header])
+
+    assert response.status_code == 400
+
+    resp_json = json.loads(response.get_data(as_text=True))
+
+    assert resp_json['errors'][0]['error'] == 'BadRequestError'
+    assert 'Missing personalisation: Missing' in resp_json['errors'][0]['message']
+
+
+def test_post_template_with_non_existent_template_id_returns_404(client, sample_service):
+    auth_header = create_authorization_header(service_id=sample_service.id)
+
+    random_template_id = str(uuid.uuid4())
+
+    response = client.post(
+        path='/v2/template/{}/preview'.format(random_template_id),
+        data=json.dumps(valid_data),
+        headers=[('Content-Type', 'application/json'), auth_header])
+
+    assert response.status_code == 404
+    assert response.headers['Content-type'] == 'application/json'
+
+    json_response = json.loads(response.get_data(as_text=True))
+
+    assert json_response == {
+        "errors": [
+            {
+                "error": "NoResultFound",
+                "message": "No result found"
+            }
+        ],
+        "status_code": 404
+    }