paperwork: Improve performance of random_certifications testing strategy

paperwork/tests.py

@@ -1,3 +1,5 @@
+from itertools import chain
+
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Permission
 from django.contrib.contenttypes.models import ContentType
@@ -78,29 +80,42 @@ class InstructorOrVendorReportTestCase(PermissionRequiredViewTestCaseMixin, Test
 
 
 @st.composite
-def random_certifications(draw):
-    departments = draw(st.lists(from_model(Department), min_size=1))
-    definitions = draw(
-        st.lists(
-            from_model(
-                CertificationDefinition, department=st.sampled_from(departments)
-            ),
-            min_size=1,
-        )
-    )
-    certification_versions = draw(
-        st.lists(
-            from_model(CertificationVersion, definition=st.sampled_from(definitions)),
-            min_size=1,
-        )
-    )
-
-    return draw(
-        st.lists(
+def random_certifications(
+    draw,
+) -> list[Certification]:
+    def certifications(version: CertificationVersion):
+        return st.lists(
             from_model(
                 Certification,
                 number=st.none(),
-                certification_version=st.sampled_from(certification_versions),
+                certification_version=st.just(version),
+            ),
+            max_size=10,
+        )
+
+    def versions_with_certifications(definition: CertificationDefinition):
+        return st.lists(
+            from_model(CertificationVersion, definition=st.just(definition)).flatmap(
+                certifications
+            ),
+            max_size=2,
+        )
+
+    def definitions_with_versions(department: Department):
+        return st.lists(
+            from_model(CertificationDefinition, department=st.just(department)).flatmap(
+                versions_with_certifications
+            ),
+            max_size=2,
+        )
+
+    return draw(
+        st.lists(
+            from_model(Department).flatmap(definitions_with_versions),
+            max_size=2,
+        ).map(
+            lambda x: list(
+                chain.from_iterable(chain.from_iterable(chain.from_iterable(x)))
             )
         )
     )
@@ -111,7 +126,7 @@ class CertifiersReportTestCase(PermissionRequiredViewTestCaseMixin, TestCase):
     path = "/paperwork/certifiers"
 
     @given(certifications=random_certifications())
-    def test_certifers_report(self, certifications: list[Certification]) -> None:
+    def test_certifiers_report(self, certifications: list[Certification]) -> None:
         self.client.force_login(self.user_with_permission)
         response = self.client.get(self.path)
         self.assertEqual(response.status_code, 200)