Issue 823 improve textcha for registration

conference/accounts.py

@@ -1,4 +1,5 @@
 import random
+import re
 
 from django import forms
 from django.conf import settings
@@ -217,6 +218,7 @@ class NewAccountForm(forms.Form):
 
     # Additional captcha field with simple python questions
     # https://github.com/EuroPython/epcon/issues/703
+    # https://github.com/EuroPython/epcon/issues/823
     captcha_question = forms.CharField(widget=forms.HiddenInput)
     captcha_answer = forms.CharField()
 
@@ -243,8 +245,10 @@ def get_random_captcha_question(self):
 
     def clean_captcha_answer(self):
         question = self.cleaned_data['captcha_question']
-        cq = CaptchaQuestion.objects.get(question=question)
-        if cq.answer.strip() != self.cleaned_data['captcha_answer'].strip():
+        answer = self.cleaned_data['captcha_answer'].strip()
+        correct_answers = CaptchaQuestion.objects.get(question=question).answer
+        answer_regx = re.compile(correct_answers, re.IGNORECASE)
+        if not answer_regx.match(answer):
             raise forms.ValidationError("Sorry, that's a wrong answer")
         return self.cleaned_data['captcha_question']
 

conference/migrations/0032_add_instructions_to_textcha_question_verbose_name.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.24 on 2021-07-04 10:59
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('conference', '0031_update_streamset_help_text'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='captchaquestion',
+            name='answer',
+            field=models.CharField(max_length=255, verbose_name='answer (use a regular expression to capture possible answers e.g. "(python|the python programming language)" case is ignored)'),
+        ),
+    ]

conference/models.py

@@ -1344,7 +1344,12 @@ class NoQuestionsAvailable(Exception):
         pass
 
     question = models.CharField(max_length=255)
-    answer   = models.CharField(max_length=255)
+    answer   = models.CharField(max_length=255,
+                                verbose_name='answer (use a regular expression'
+                                ' to capture possible answers e.g.'
+                                ' "(python|the python programming language)"'
+                                ' case is ignored)'
+                                )
     enabled  = models.BooleanField(default=True)
 
     objects = CaptchaQuestionManager()

tests/test_user_login_and_registration.py

@@ -195,8 +195,10 @@ def test_703_test_captcha_questions(client):
     """
 
     QUESTION = "Can you foo in Python?"
-    ANSWER = "Yes you can"
-    CaptchaQuestion.objects.create(question=QUESTION, answer=ANSWER)
+    ANSWER = "(Yes|yeah|Definitely|CERTAINLY)"
+    CaptchaQuestion.objects.create(
+        question=QUESTION, answer=ANSWER
+    )
     Email.objects.create(code="verify-account")
 
     sign_up_url = reverse("accounts:signup_step_1_create_account")
@@ -246,7 +248,7 @@ def test_703_test_captcha_questions(client):
             "password1": "password",
             "password2": "password",
             "captcha_question": QUESTION,
-            "captcha_answer": ANSWER,
+            "captcha_answer": "YEAH",
             "i_accept_privacy_policy": True,
         },
     )