Guess people’s names when they’re invited

Most people’s names, especially in government are in the format
firstname.lastname@department.gov.uk. This means that you can pretty
reliably guess that their name is ‘Firstname Lastname’.

When users are invited to Notify we know their email address already.

So this commit pre-populates the registration form based on this guess.

This is a nice little detail, but it should also stop the browser
pre-filling the name field with someone’s email address (which I think
happens because the browser assumes a registration form will have an
email field).

tests/app/main/views/test_register.py

@@ -170,6 +170,34 @@ def test_register_with_existing_email_sends_emails(
     assert response.location == url_for('main.registration_continue', _external=True)
 
 
+@pytest.mark.parametrize('email_address, expected_value', [
+    ("example123@example.com", ""),
+    ("first.last@example.com", "First Last"),
+    ("first.middle.last@example.com", "First Middle Last"),
+    ("first.last-last@example.com", "First Last-Last"),
+    ("first.o'last@example.com", "First O’Last"),
+    ("first.last+testing@example.com", "First Last"),
+    ("first.last+testing+testing@example.com", "First Last"),
+])
+def test_shows_registration_page_from_invite(
+    client_request,
+    fake_uuid,
+    email_address,
+    expected_value,
+):
+    with client_request.session_transaction() as session:
+        session['invited_user'] = InvitedUser(
+            fake_uuid, fake_uuid, "",
+            email_address,
+            ["manage_users"],
+            "pending",
+            datetime.utcnow(),
+            'sms_auth',
+        ).serialize()
+    page = client_request.get('main.register_from_invite')
+    assert page.select_one('input[name=name]')['value'] == expected_value
+
+
 def test_register_from_invite(
     client,
     fake_uuid,
@@ -199,6 +227,13 @@ def test_register_from_invite(
     )
     assert response.status_code == 302
     assert response.location == url_for('main.verify', _external=True)
+    mock_register_user.assert_called_once_with(
+        'Registered in another Browser',
+        invited_user.email_address,
+        '+4407700900460',
+        'somreallyhardthingtoguess',
+        'sms_auth',
+    )
 
 
 def test_register_from_invite_when_user_registers_in_another_browser(