Bug 1625451 - Provide default for application field

treeherder/perf/migrations/0028_default_application_to_empty_str.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.0.3 on 2020-04-01 11:19
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('perf', '0027_support_perfherder_settings'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='performancesignature',
+            name='application',
+            field=models.CharField(default='', help_text="Application that runs the signature's tests. Generally used to record browser's name, but not necessarily.", max_length=10),
+        ),
+    ]

treeherder/perf/models.py

@@ -40,7 +40,7 @@ class PerformanceSignature(models.Model):
     option_collection = models.ForeignKey(OptionCollection, on_delete=models.CASCADE)
     suite = models.CharField(max_length=80)
     test = models.CharField(max_length=80, blank=True)
-    application = models.CharField(max_length=10, null=True,
+    application = models.CharField(max_length=10, default='',
                                    help_text="Application that runs the signature's tests. "
                                              "Generally used to record browser's name, but not necessarily.")
     lower_is_better = models.BooleanField(default=True)