Validate and format postcode for the API letter sending flow.

app/v2/errors.py

@@ -1,7 +1,7 @@
 import json
 
 from flask import jsonify, current_app, request
-from jsonschema import ValidationError
+from jsonschema import ValidationError as JsonSchemaValidationError
 from notifications_utils.recipients import InvalidEmailError
 from sqlalchemy.exc import DataError
 from sqlalchemy.orm.exc import NoResultFound
@@ -57,6 +57,15 @@ class BadRequestError(InvalidRequest):
         self.message = message if message else self.message
 
 
+class ValidationError(InvalidRequest):
+    message = "Your notification has failed validation"
+
+    def __init__(self, fields=[], message=None, status_code=400):
+        self.status_code = status_code
+        self.fields = fields
+        self.message = message if message else self.message
+
+
 class PDFNotReadyError(BadRequestError):
     def __init__(self):
         super().__init__(message='PDF not available yet, try again later', status_code=400)
@@ -77,7 +86,7 @@ def register_errors(blueprint):
         response = jsonify(error.to_dict_v2()), error.status_code
         return response
 
-    @blueprint.errorhandler(ValidationError)
+    @blueprint.errorhandler(JsonSchemaValidationError)
     def validation_error(error):
         current_app.logger.info(error)
         return jsonify(json.loads(error.message)), 400

app/v2/notifications/post_notifications.py

@@ -2,7 +2,9 @@ import base64
 import functools
 
 from flask import request, jsonify, current_app, abort
-from notifications_utils.recipients import try_validate_and_format_phone_number
+from notifications_utils.recipients import (
+    format_postcode_for_printing, is_a_real_uk_postcode, try_validate_and_format_phone_number
+)
 
 from app import api_user, authenticated_service, notify_celery, document_download_client
 from app.celery.letters_pdf_tasks import create_letters_pdf, process_virus_scan_passed
@@ -44,7 +46,7 @@ from app.notifications.validators import (
     validate_template,
 )
 from app.schema_validation import validate
-from app.v2.errors import BadRequestError
+from app.v2.errors import BadRequestError, ValidationError
 from app.v2.notifications import v2_notification_blueprint
 from app.v2.notifications.create_response import (
     create_post_sms_response_from_notification,
@@ -267,12 +269,18 @@ def process_letter_notification(*, letter_data, api_key, template, reply_to_text
                                                         template=template,
                                                         reply_to_text=reply_to_text)
 
+    postcode = letter_data['personalisation']['postcode']
+    if not is_a_real_uk_postcode(postcode):
+        raise ValidationError(message='A real UK postcode is required.')
+
     test_key = api_key.key_type == KEY_TYPE_TEST
 
     # if we don't want to actually send the letter, then start it off in SENDING so we don't pick it up
     status = NOTIFICATION_CREATED if not test_key else NOTIFICATION_SENDING
     queue = QueueNames.CREATE_LETTERS_PDF if not test_key else QueueNames.RESEARCH_MODE
 
+    letter_data['personalisation']['postcode'] = format_postcode_for_printing(postcode)
+
     notification = create_letter_notification(letter_data=letter_data,
                                               template=template,
                                               api_key=api_key,

tests/app/v2/notifications/test_post_letter_notifications.py

@@ -118,6 +118,56 @@ def test_post_letter_notification_sets_postage(
     assert notification.postage == "first"
 
 
+def test_post_letter_notification_formats_postcode(
+    client, notify_db_session, mocker
+):
+    service = create_service(service_permissions=[LETTER_TYPE])
+    template = create_template(service, template_type="letter")
+    mocker.patch('app.celery.tasks.letters_pdf_tasks.create_letters_pdf.apply_async')
+    data = {
+        'template_id': str(template.id),
+        'personalisation': {
+            'address_line_1': 'Her Royal Highness Queen Elizabeth II',
+            'address_line_2': 'Buckingham Palace',
+            'address_line_3': 'London',
+            'postcode': '  Sw1  1aa   ',
+            'name': 'Lizzie'
+        }
+    }
+
+    resp_json = letter_request(client, data, service_id=service.id)
+
+    assert validate(resp_json, post_letter_response) == resp_json
+    notification = Notification.query.one()
+    assert notification.personalisation["postcode"] == "SW1 1AA"
+
+
+def test_post_letter_notification_throws_error_for_bad_postcode(
+    client, notify_db_session, mocker
+):
+    service = create_service(service_permissions=[LETTER_TYPE])
+    template = create_template(service, template_type="letter", postage="first")
+    mocker.patch('app.celery.tasks.letters_pdf_tasks.create_letters_pdf.apply_async')
+    data = {
+        'template_id': str(template.id),
+        'personalisation': {
+            'address_line_1': 'Her Royal Highness Queen Elizabeth II',
+            'address_line_2': 'Buckingham Palace',
+            'address_line_3': 'London',
+            'postcode': 'not a real postcode',
+            'name': 'Lizzie'
+        }
+    }
+
+    error_json = letter_request(client, data, service_id=service.id, _expected_status=400)
+
+    assert error_json['status_code'] == 400
+    assert error_json['errors'] == [{
+        'error': 'ValidationError',
+        'message': 'A real UK postcode is required.'
+    }]
+
+
 @pytest.mark.parametrize('env', [
     'staging',
     'live',
@@ -366,7 +416,7 @@ def test_post_letter_notification_is_delivered_but_still_creates_pdf_if_in_trial
 
     data = {
         "template_id": sample_trial_letter_template.id,
-        "personalisation": {'address_line_1': 'Foo', 'address_line_2': 'Bar', 'postcode': 'Baz'}
+        "personalisation": {'address_line_1': 'Foo', 'address_line_2': 'Bar', 'postcode': 'BA5 5AB'}
     }
 
     letter_request(client, data=data, service_id=sample_trial_letter_template.service_id, key_type=KEY_TYPE_TEST)
@@ -411,7 +461,7 @@ def test_post_letter_notification_persists_notification_reply_to_text(
     template = create_template(service=service, template_type='letter', reply_to=letter_contact.id)
     data = {
         "template_id": template.id,
-        "personalisation": {'address_line_1': 'Foo', 'address_line_2': 'Bar', 'postcode': 'Baz'}
+        "personalisation": {'address_line_1': 'Foo', 'address_line_2': 'Bar', 'postcode': 'BA5 5AB'}
     }
     letter_request(client, data=data, service_id=service.id, key_type=KEY_TYPE_NORMAL)