set default value of year of diagnosis to None - fixes #106

smash/web/migrations/0036_year_of_diagnosis_default.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2017-04-25 07:28
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('web', '0035_screening_number'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='subject',
+            name='year_of_diagnosis',
+            field=models.IntegerField(blank=True, null=True, verbose_name=b'Year of diagnosis (YYYY)'),
+        ),
+        migrations.RunSQL(
+            "UPDATE web_subject SET year_of_diagnosis=NULL WHERE year_of_diagnosis = 0;",
+            "UPDATE web_subject SET year_of_diagnosis=0 WHERE year_of_diagnosis = NULL;"),
+    ]

smash/web/models/subject.py

@@ -138,7 +138,6 @@ class Subject(models.Model):
                                  verbose_name='Diagnosis'
                                  )
     year_of_diagnosis = models.IntegerField(
-        default=0,
         null=True,
         blank=True,
         verbose_name='Year of diagnosis (YYYY)'

smash/web/tests/test_SubjectAddForm.py

@@ -39,6 +39,7 @@ class SubjectAddFormTests(TestCase):
         form = SubjectAddForm(data=form_data, user=self.user)
         form.is_valid()
         self.assertTrue(form.is_valid())
+        self.assertIsNone(form.fields['year_of_diagnosis'].initial)
         form.save()
 
         form2 = SubjectAddForm(data=form_data, user=self.user)