Create a dataclass for version info

Convert from fixed-shape dicts to a dataclass. Preserve almost all
code semantics identically -- e.g., variable assignments in
`readthedocs.api.v2.utils` may be micro-optimizations which could be
important.

The only intentional semantic change included here (other than the
change in types) is in
`readthedocs.projects.tasks.mixins`, where a list comprehension is
replaced with a generator expression.

Author: sirosen

readthedocs/api/v2/utils.py

@@ -48,8 +48,8 @@ def sync_versions_to_db(project, versions, type):
     has_user_stable = False
     has_user_latest = False
     for version in versions:
-        version_id = version["identifier"]
-        version_name = version["verbose_name"]
+        version_id = version.identifier
+        version_name = version.verbose_name
         if version_name == STABLE_VERBOSE_NAME:
             has_user_stable = True
             created_version, created = _set_or_create_version(
@@ -170,8 +170,8 @@ def _set_or_create_version(project, slug, version_id, verbose_name, type_):
 def _get_deleted_versions_qs(project, tags_data, branches_data):
     # We use verbose_name for tags
     # because several tags can point to the same identifier.
-    versions_tags = [version["verbose_name"] for version in tags_data]
-    versions_branches = [version["identifier"] for version in branches_data]
+    versions_tags = [version.verbose_name for version in tags_data]
+    versions_branches = [version.identifier for version in branches_data]
 
     to_delete_qs = (
         project.versions(manager=INTERNAL)

readthedocs/builds/tasks.py

@@ -33,6 +33,7 @@
 from readthedocs.integrations.models import HttpExchange
 from readthedocs.notifications.models import Notification
 from readthedocs.oauth.notifications import MESSAGE_OAUTH_BUILD_STATUS_FAILURE
+from readthedocs.projects.datatypes import ProjectVersionInfo
 from readthedocs.projects.models import Project
 from readthedocs.projects.models import WebHookEvent
 from readthedocs.storage import build_commands_storage
@@ -274,22 +275,33 @@ def delete_closed_external_versions(limit=200, days=30 * 3):
 
 
 @app.task(max_retries=1, default_retry_delay=60, queue="web")
-def sync_versions_task(project_pk, tags_data, branches_data, **kwargs):
+def sync_versions_task(
+    project_pk: int,
+    tags_data: list[ProjectVersionInfo],
+    branches_data: list[ProjectVersionInfo],
+    **kwargs: object,
+):
     """
     Sync the version data in the repo (from build server) into our database.
 
-    Creates new Version objects for tags/branches that aren't tracked in the database,
-    and deletes Version objects for tags/branches that don't exists in the repository.
+    Creates new Version objects for tags/branches that aren't tracked in the
+    database, and deletes Version objects for tags/branches that don't exists
+    in the repository.
 
-    :param tags_data: List of dictionaries with ``verbose_name`` and ``identifier``
+    :param tags_data: List of version descriptions
                       Example: [
-                          {"verbose_name": "v1.0.0",
-                           "identifier": "67a9035990f44cb33091026d7453d51606350519"},
+                          ProjectVersionInfo(
+                              verbose_name="v1.0.0",
+                              identifier="67a9035990f44cb33091026d7453d51606350519",
+                          )
                       ].
-    :param branches_data: Same as ``tags_data`` but for branches (branch name, branch identifier).
+    :param branches_data: Same as ``tags_data`` but for branches (branch name,
+        branch identifier).
                       Example: [
-                          {"verbose_name": "latest",
-                           "identifier": "main"},
+                          ProjectVersionInfo(
+                              verbose_name="latest",
+                              identifier="main",
+                          )
                       ].
     :returns: `True` or `False` if the task succeeded.
     """

readthedocs/projects/datatypes.py

@@ -0,0 +1,23 @@
+"""Simple datatypes defined using dataclasses, for describing project data.
+
+Contrast this with the similar 'models' module, which defines Pydantic model
+classes.
+"""
+
+import dataclasses
+
+
+@dataclasses.dataclass
+class ProjectVersionInfo:
+    """
+    Version information for a project associated with a branch or tag.
+
+    The name fields is the end-user facing description, e.g., as seen in the
+    version selector menu.
+
+    The identifier identifies the source for the build, e.g., a branch or
+    commit hash.
+    """
+
+    verbose_name: str
+    identifier: str

readthedocs/projects/tasks/mixins.py

@@ -7,6 +7,7 @@
 from readthedocs.builds.constants import STABLE_VERBOSE_NAME
 from readthedocs.builds.models import APIVersion
 
+from ..datatypes import ProjectVersionInfo
 from ..exceptions import RepositoryError
 from ..models import Feature
 
@@ -50,18 +51,18 @@ def sync_versions(self, vcs_repository):
         )
 
         tags_data = [
-            {
-                "identifier": v.identifier,
-                "verbose_name": v.verbose_name,
-            }
+            ProjectVersionInfo(
+                verbose_name=v.verbose_name,
+                identifier=v.identifier,
+            )
             for v in tags
         ]
 
         branches_data = [
-            {
-                "identifier": v.identifier,
-                "verbose_name": v.verbose_name,
-            }
+            ProjectVersionInfo(
+                verbose_name=v.verbose_name,
+                identifier=v.identifier,
+            )
             for v in branches
         ]
 
@@ -78,7 +79,11 @@ def sync_versions(self, vcs_repository):
             branches_data=branches_data,
         )
 
-    def validate_duplicate_reserved_versions(self, tags_data, branches_data):
+    def validate_duplicate_reserved_versions(
+        self,
+        tags_data: list[ProjectVersionInfo],
+        branches_data: list[ProjectVersionInfo],
+    ) -> None:
         """
         Check if there are duplicated names of reserved versions.
 
@@ -88,8 +93,7 @@ def validate_duplicate_reserved_versions(self, tags_data, branches_data):
 
         :param data: Dict containing the versions from tags and branches
         """
-        version_names = [version["verbose_name"] for version in tags_data + branches_data]
-        counter = Counter(version_names)
+        counter = Counter(v.verbose_name for v in tags_data + branches_data)
         for reserved_name in [STABLE_VERBOSE_NAME, LATEST_VERBOSE_NAME]:
             if counter[reserved_name] > 1:
                 raise RepositoryError(