feat(models): validate active TransitAgency

when active=True, validate that:

- there are values for user-facing info fields like names, logos, phone, etc.
- templates exist

benefits/core/models.py

@@ -6,8 +6,10 @@
 import importlib
 import logging
 import os
+from pathlib import Path
 import uuid
 
+from django import template
 from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.contrib.auth.models import Group, User
@@ -25,6 +27,23 @@
 logger = logging.getLogger(__name__)
 
 
+def template_path(template_name: str) -> Path:
+    """Get a `pathlib.Path` for the named template, or None if it can't be found.
+
+    A `template_name` is the app-local name, e.g. `enrollment/success.html`.
+
+    Adapted from https://stackoverflow.com/a/75863472.
+    """
+    if template_name:
+        for engine in template.engines.all():
+            for loader in engine.engine.template_loaders:
+                for origin in loader.get_template_sources(template_name):
+                    path = Path(origin.name)
+                    if path.exists() and path.is_file():
+                        return path
+    return None
+
+
 class SecretNameField(models.SlugField):
     """Field that stores the name of a secret held in a secret store.
 
@@ -292,6 +311,31 @@ def transit_processor_client_secret(self):
     def enrollment_flows(self):
         return self.enrollmentflow_set
 
+    def clean(self):
+        if self.active:
+            errors = {}
+            message = "This field is required for active transit agencies."
+            needed = dict(
+                short_name=self.short_name,
+                long_name=self.long_name,
+                phone=self.phone,
+                info_url=self.info_url,
+                logo_large=self.logo_large,
+                logo_small=self.logo_small,
+            )
+            for k, v in needed.items():
+                if not v:
+                    errors[k] = ValidationError(message)
+            if errors:
+                raise ValidationError(errors)
+
+            # since templates are calculated from the pattern or the override field
+            # we can't add a field-level validation error
+            # so just raise directly for a missing template
+            for t in [self.index_template, self.eligibility_index_template]:
+                if not template_path(t):
+                    raise ValidationError(f"Template not found: {t}")
+
     @staticmethod
     def by_id(id):
         """Get a TransitAgency instance by its ID."""
@@ -521,6 +565,17 @@ def uses_claims_verification(self):
         """True if this flow verifies via the claims provider and has a scope and claim. False otherwise."""
         return self.claims_provider is not None and bool(self.claims_scope) and bool(self.claims_eligibility_claim)
 
+    @property
+    def claims_scheme(self):
+        return self.claims_scheme_override or self.claims_provider.scheme
+
+    @property
+    def claims_all_claims(self):
+        claims = [self.claims_eligibility_claim]
+        if self.claims_extra_claims is not None:
+            claims.extend(self.claims_extra_claims.split())
+        return claims
+
     @property
     def eligibility_verifier(self):
         """A str representing the entity that verifies eligibility for this flow.
@@ -548,23 +603,6 @@ def enrollment_success_template(self):
         else:
             return self.enrollment_success_template_override or f"{prefix}--{self.agency_card_name}.html"
 
-    def eligibility_form_instance(self, *args, **kwargs):
-        """Return an instance of this flow's EligibilityForm, or None."""
-        if not bool(self.eligibility_form_class):
-            return None
-
-        # inspired by https://stackoverflow.com/a/30941292
-        module_name, class_name = self.eligibility_form_class.rsplit(".", 1)
-        FormClass = getattr(importlib.import_module(module_name), class_name)
-
-        return FormClass(*args, **kwargs)
-
-    @staticmethod
-    def by_id(id):
-        """Get an EnrollmentFlow instance by its ID."""
-        logger.debug(f"Get {EnrollmentFlow.__name__} by id: {id}")
-        return EnrollmentFlow.objects.get(id=id)
-
     def clean(self):
         supports_expiration = self.supports_expiration
         expiration_days = self.expiration_days
@@ -584,18 +622,22 @@ def clean(self):
             if errors:
                 raise ValidationError(errors)
 
-    @property
-    def claims_scheme(self):
-        if not self.claims_scheme_override:
-            return self.claims_provider.scheme
-        return self.claims_scheme_override
+    def eligibility_form_instance(self, *args, **kwargs):
+        """Return an instance of this flow's EligibilityForm, or None."""
+        if not bool(self.eligibility_form_class):
+            return None
 
-    @property
-    def claims_all_claims(self):
-        claims = [self.claims_eligibility_claim]
-        if self.claims_extra_claims is not None:
-            claims.extend(self.claims_extra_claims.split())
-        return claims
+        # inspired by https://stackoverflow.com/a/30941292
+        module_name, class_name = self.eligibility_form_class.rsplit(".", 1)
+        FormClass = getattr(importlib.import_module(module_name), class_name)
+
+        return FormClass(*args, **kwargs)
+
+    @staticmethod
+    def by_id(id):
+        """Get an EnrollmentFlow instance by its ID."""
+        logger.debug(f"Get {EnrollmentFlow.__name__} by id: {id}")
+        return EnrollmentFlow.objects.get(id=id)
 
 
 class EnrollmentEvent(models.Model):

tests/pytest/conftest.py

@@ -195,6 +195,8 @@ def model_TransitAgency(model_PemData, model_TransitProcessor):
         eligibility_api_jws_signing_alg="alg",
         index_template_override="core/agency-index.html",
         eligibility_index_template_override="eligibility/index.html",
+        logo_large="agencies/cst-lg.png",
+        logo_small="agencies/cst-sm.png",
     )
 
     return agency

tests/pytest/core/test_models.py

@@ -1,4 +1,6 @@
 from datetime import timedelta
+from pathlib import Path
+
 from django.conf import settings
 from django.contrib.auth.models import Group, User
 from django.core.exceptions import ValidationError
@@ -7,6 +9,7 @@
 import pytest
 
 from benefits.core.models import (
+    template_path,
     SecretNameField,
     EnrollmentFlow,
     TransitAgency,
@@ -24,6 +27,25 @@ def mock_requests_get_pem_data(mocker):
     return mocker.patch("benefits.core.models.requests.get", return_value=mocker.Mock(text="PEM text"))
 
 
+@pytest.mark.django_db
+@pytest.mark.parametrize(
+    "input_template,expected_path",
+    [
+        ("error.html", f"{settings.BASE_DIR}/benefits/templates/error.html"),
+        ("core/index.html", f"{settings.BASE_DIR}/benefits/core/templates/core/index.html"),
+        ("eligibility/start.html", f"{settings.BASE_DIR}/benefits/eligibility/templates/eligibility/start.html"),
+        ("", None),
+        ("nope.html", None),
+        ("core/not-there.html", None),
+    ],
+)
+def test_template_path(input_template, expected_path):
+    if expected_path:
+        assert template_path(input_template) == Path(expected_path)
+    else:
+        assert template_path(input_template) is None
+
+
 def test_SecretNameField_init():
     field = SecretNameField()
 
@@ -538,6 +560,45 @@ def test_agency_logo_large(model_TransitAgency):
     assert agency_logo_large(model_TransitAgency, "local_filename.png") == "agencies/test-lg.png"
 
 
+@pytest.mark.django_db
+def test_TransitAgency_clean(model_TransitAgency_inactive):
+    model_TransitAgency_inactive.short_name = ""
+    model_TransitAgency_inactive.long_name = ""
+    model_TransitAgency_inactive.phone = ""
+    model_TransitAgency_inactive.info_url = ""
+    model_TransitAgency_inactive.logo_large = ""
+    model_TransitAgency_inactive.logo_small = ""
+    # agency is inactive, OK to have incomplete fields
+    model_TransitAgency_inactive.clean()
+
+    # now mark it active and expect failure on clean()
+    model_TransitAgency_inactive.active = True
+    with pytest.raises(ValidationError) as e:
+        model_TransitAgency_inactive.clean()
+
+    errors = e.value.error_dict
+
+    assert "short_name" in errors
+    assert "long_name" in errors
+    assert "phone" in errors
+    assert "info_url" in errors
+    assert "logo_large" in errors
+    assert "logo_small" in errors
+
+
+@pytest.mark.django_db
+@pytest.mark.parametrize("template_attribute", ["index_template_override", "eligibility_index_template_override"])
+def test_TransitAgency_clean_templates(model_TransitAgency_inactive, template_attribute):
+    setattr(model_TransitAgency_inactive, template_attribute, "does/not/exist.html")
+    # agency is inactive, OK to have missing template
+    model_TransitAgency_inactive.clean()
+
+    # now mark it active and expect failure on clean()
+    model_TransitAgency_inactive.active = True
+    with pytest.raises(ValidationError, match="Template not found: does/not/exist.html"):
+        model_TransitAgency_inactive.clean()
+
+
 @pytest.mark.django_db
 def test_EnrollmentEvent_create(model_TransitAgency, model_EnrollmentFlow):
     ts = timezone.now()