Add support for successful build prefetch (#11613)

We use both latest build and latest successful build in the project
listing template.

Author: agjohnson

readthedocs/projects/models.py

@@ -575,6 +575,7 @@ class Project(models.Model):
 
     # Property used for storing the latest build for a project when prefetching
     LATEST_BUILD_CACHE = "_latest_build"
+    LATEST_SUCCESSFUL_BUILD_CACHE = "_latest_successful_build"
 
     class Meta:
         ordering = ("slug",)
@@ -920,6 +921,13 @@ def conf_dir(self, version=LATEST):
 
     @property
     def has_good_build(self):
+        # Check if there is `_latest_successful_build` attribute in the Queryset.
+        # Used for database optimization.
+        if hasattr(self, self.LATEST_SUCCESSFUL_BUILD_CACHE):
+            if build_successful := getattr(self, self.LATEST_SUCCESSFUL_BUILD_CACHE):
+                return build_successful[0]
+            return None
+
         # Check if there is `_good_build` annotation in the Queryset.
         # Used for Database optimization.
         if hasattr(self, "_good_build"):

readthedocs/projects/querysets.py

@@ -132,17 +132,33 @@ def prefetch_latest_build(self):
         from readthedocs.builds.models import Build
 
         # Prefetch the latest build for each project.
-        subquery = Subquery(
+        subquery_build_latest = Subquery(
             Build.internal.filter(project=OuterRef("project_id"))
             .order_by("-date")
             .values_list("id", flat=True)[:1]
         )
-        latest_build = Prefetch(
+        prefetch_build_latest = Prefetch(
             "builds",
-            Build.internal.filter(pk__in=subquery),
+            Build.internal.filter(pk__in=subquery_build_latest),
             to_attr=self.model.LATEST_BUILD_CACHE,
         )
-        return self.prefetch_related(latest_build)
+
+        # Prefetch the latest successful build for each project.
+        subquery_build_successful = Subquery(
+            Build.internal.filter(project=OuterRef("project_id"))
+            .order_by("-date")
+            .values_list("id", flat=True)[:1]
+        )
+        prefetch_build_successful = Prefetch(
+            "builds",
+            Build.internal.filter(pk__in=subquery_build_successful),
+            to_attr=self.model.LATEST_SUCCESSFUL_BUILD_CACHE,
+        )
+
+        return self.prefetch_related(
+            prefetch_build_latest,
+            prefetch_build_successful,
+        )
 
     # Aliases