test_fixtures: Refactor to have template_database_status API.

In this commit we are essentially just refactoring the function
is_template_database_current to be called template_database_status
and adjusting the return values accordingly.
This is essentially a preparatory commit for the upcoming commits
which will essentially enable us to not throw away entire DB and
rebuild from scratch if only running migrations could do the job.

tools/lib/provision.py

@@ -316,12 +316,12 @@ def main(options):
         # of the development environment (it just uses the development
         # environment to build a release tarball).
 
-        # Need to set up Django before using is_template_database_current
+        # Need to set up Django before using template_database_status
         os.environ.setdefault("DJANGO_SETTINGS_MODULE", "zproject.settings")
         import django
         django.setup()
 
-        from zerver.lib.test_fixtures import is_template_database_current
+        from zerver.lib.test_fixtures import template_database_status
 
         try:
             from zerver.lib.queue import SimpleQueueClient
@@ -336,20 +336,22 @@ def main(options):
             print("RabbitMQ is already configured.")
 
         migration_status_path = os.path.join(UUID_VAR_PATH, "migration_status_dev")
-        if options.is_force or not is_template_database_current(
+        dev_template_db_status = template_database_status(
-                migration_status=migration_status_path,
+            migration_status=migration_status_path,
-                settings="zproject.settings",
+            settings="zproject.settings",
-                database_name="zulip",
+            database_name="zulip",
-        ):
+        )
+        if options.is_force or dev_template_db_status == 'needs_rebuild':
             run(["tools/setup/postgres-init-dev-db"])
             run(["tools/do-destroy-rebuild-database"])
-        else:
+        elif dev_template_db_status == 'current':
             print("No need to regenerate the dev DB.")
 
-        if options.is_force or not is_template_database_current():
+        test_template_db_status = template_database_status()
+        if options.is_force or test_template_db_status == 'needs_rebuild':
             run(["tools/setup/postgres-init-test-db"])
             run(["tools/do-destroy-rebuild-test-database"])
-        else:
+        elif test_template_db_status == 'current':
             print("No need to regenerate the test DB.")
 
         # Consider updating generated translations data: both `.mo`

tools/lib/test_server.py

@@ -19,7 +19,7 @@ TOOLS_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 if TOOLS_DIR not in sys.path:
     sys.path.insert(0, os.path.dirname(TOOLS_DIR))
 
-from zerver.lib.test_fixtures import is_template_database_current
+from zerver.lib.test_fixtures import template_database_status
 
 def set_up_django(external_host):
     # type: (str) -> None
@@ -63,7 +63,8 @@ def test_server_running(force: bool=False, external_host: str='testserver',
 
     if use_db:
         generate_fixtures_command = ['tools/setup/generate-fixtures']
-        if not is_template_database_current():
+        test_template_db_status = template_database_status()
+        if test_template_db_status == 'needs_rebuild':
             generate_fixtures_command.append('--force')
         subprocess.check_call(generate_fixtures_command)
 

tools/test-backend

@@ -171,7 +171,7 @@ if __name__ == "__main__":
     os.environ["http_proxy"] = ""
     os.environ["https_proxy"] = ""
 
-    from zerver.lib.test_fixtures import is_template_database_current
+    from zerver.lib.test_fixtures import template_database_status
 
     from tools.lib.test_script import (
         get_provisioning_status,
@@ -344,7 +344,8 @@ if __name__ == "__main__":
     # files, since part of setup is importing the models for all applications in INSTALLED_APPS.
     django.setup()
 
-    if options.generate_fixtures or not is_template_database_current():
+    test_template_db_status = template_database_status()
+    if options.generate_fixtures or test_template_db_status == 'needs_rebuild':
         generate_fixtures_command = [os.path.join(TOOLS_DIR, 'setup', 'generate-fixtures')]
         generate_fixtures_command.append('--force')
         subprocess.call(generate_fixtures_command)

zerver/lib/test_fixtures.py

@@ -107,14 +107,15 @@ def check_setting_hash(setting_name: str, status_dir: str) -> bool:
 
     return _check_hash(source_hash_file, target_content)
 
-def is_template_database_current(
+def template_database_status(
         database_name: str='zulip_test_template',
         migration_status: Optional[str]=None,
         settings: str='zproject.test_settings',
         status_dir: Optional[str]=None,
         check_files: Optional[List[str]]=None,
-        check_settings: Optional[List[str]]=None) -> bool:
+        check_settings: Optional[List[str]]=None) -> str:
-    # Using str type for check_files because re.split doesn't accept unicode
+    # This function returns a status string specifying the type of
+    # state the template db is in and thus the kind of action required.
     if check_files is None:
         check_files = [
             'zilencer/management/commands/populate_db.py',
@@ -144,6 +145,7 @@ def is_template_database_current(
                                     for setting_name in check_settings])
         hash_status = files_hash_status and settings_hash_status
 
-        return are_migrations_the_same(migration_status, settings=settings) and hash_status
+        if are_migrations_the_same(migration_status, settings=settings) and hash_status:
+            return 'current'
 
-    return False
+    return 'needs_rebuild'