Turn on redirects two_factor_email

This is part of the work to make sure user is redirected
to the page they initially were meant to visit after
they sign in.

app/main/views/two_factor.py

@@ -36,6 +36,7 @@ def two_factor_email_interstitial(token):
 
 @main.route('/email-auth/<token>', methods=['POST'])
 def two_factor_email(token):
+    redirect_url = request.args.get('next')
     if current_user.is_authenticated:
         return redirect_when_logged_in(platform_admin=current_user.platform_admin)
 
@@ -48,14 +49,14 @@ def two_factor_email(token):
             current_app.config['EMAIL_2FA_EXPIRY_SECONDS']
         ))
     except SignatureExpired:
-        return render_template('views/email-link-invalid.html')
+        return render_template('views/email-link-invalid.html', redirect_url=redirect_url)
 
     user_id = token_data['user_id']
     # checks if code was already used
     logged_in, msg = user_api_client.check_verify_code(user_id, token_data['secret_code'], "email")
 
     if not logged_in:
-        return render_template('views/email-link-invalid.html')
+        return render_template('views/email-link-invalid.html', redirect_url=redirect_url)
     return log_in_user(user_id)
 
 

app/templates/views/email-link-invalid.html

@@ -11,7 +11,11 @@
   <div class="govuk-grid-column-two-thirds">
     <h1 class="heading-large">The link has expired</h1>
 
-    <p class="govuk-body"><a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('main.sign_in') }}">Sign in again</a> to get a new link.</p>
+    <p class="govuk-body">
+      <a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('main.sign_in', next=redirect_url) }}">
+        Sign in again
+      </a> to get a new link.
+  </p>
 
   </div>
 </div>

tests/app/main/views/test_two_factor.py

@@ -339,17 +339,22 @@ def test_valid_two_factor_email_link_logs_in_user(
     assert response.location == url_for('main.show_accounts_or_dashboard', _external=True)
 
 
+@pytest.mark.parametrize('redirect_url', [
+    None,
+    'blob',
+])
 def test_two_factor_email_link_has_expired(
     app_,
     valid_token,
     client,
     mock_send_verify_code,
-    fake_uuid
+    fake_uuid,
+    redirect_url
 ):
 
     with set_config(app_, 'EMAIL_2FA_EXPIRY_SECONDS', -1):
         response = client.post(
-            url_for_endpoint_with_token('main.two_factor_email', token=valid_token),
+            url_for_endpoint_with_token('main.two_factor_email', token=valid_token, next=redirect_url),
             follow_redirects=True,
         )
 
@@ -357,6 +362,8 @@ def test_two_factor_email_link_has_expired(
     page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
 
     assert page.h1.text.strip() == 'The link has expired'
+    assert page.select_one('a:contains("Sign in again")')['href'] == url_for('main.sign_in', next=redirect_url)
+
     assert mock_send_verify_code.called is False
 
 
@@ -372,20 +379,26 @@ def test_two_factor_email_link_is_invalid(
     assert normalize_spaces(
         page.select_one('.banner-dangerous').text
     ) == "There’s something wrong with the link you’ve used."
+
     assert response.status_code == 404
 
 
+@pytest.mark.parametrize('redirect_url', [
+    None,
+    'blob',
+])
 def test_two_factor_email_link_is_already_used(
     client,
     valid_token,
     mocker,
-    mock_send_verify_code
+    mock_send_verify_code,
+    redirect_url
 
 ):
     mocker.patch('app.user_api_client.check_verify_code', return_value=(False, 'Code has expired'))
 
     response = client.post(
-        url_for_endpoint_with_token('main.two_factor_email', token=valid_token),
+        url_for_endpoint_with_token('main.two_factor_email', token=valid_token, next=redirect_url),
         follow_redirects=True
     )
 
@@ -393,6 +406,8 @@ def test_two_factor_email_link_is_already_used(
     assert response.status_code == 200
 
     assert page.h1.text.strip() == 'The link has expired'
+    assert page.select_one('a:contains("Sign in again")')['href'] == url_for('main.sign_in', next=redirect_url)
+
     assert mock_send_verify_code.called is False