Compile openapi client in background when django runserver is reloading

staticfiles/management/commands/collectstatic.py

@@ -50,7 +50,13 @@ class Command(CollectStatic):
             return Path(location)
 
         Scss.compile(self.collect_scss())
-        OpenApi.compile()  # This needs to be prior to javascript bundling
+        openapi = OpenApi.compile()  # This needs to be prior to javascript bundling
+        if openapi is not None:
+            _ = openapi.wait()
+            if openapi.returncode:
+                raise RuntimeError(
+                    f"Openapi generation failed with returncode {openapi.returncode}"
+                )
         JSBundler.compile()
 
         collected = super().collect()

staticfiles/management/commands/runserver.py

@@ -15,11 +15,18 @@ class Command(Runserver):
     """Light wrapper around default runserver that integrates javascirpt auto bundling."""
 
     def run(self, **options):
-        OpenApi.compile()
-        if (
-            os.environ.get(DJANGO_AUTORELOAD_ENV) is None
-            and settings.PROCFILE_STATIC is not None
-        ):
+        is_django_reload = os.environ.get(DJANGO_AUTORELOAD_ENV) is not None
+
+        proc = OpenApi.compile()
+        # Ensure that the first runserver launch creates openapi files
+        # before the bundler starts so that it detects them
+        # When django is reloaded, we can keep this process in background
+        # to reduce reload time
+        if proc is not None and not is_django_reload:
+            _ = proc.wait()
+
+        if not is_django_reload and settings.PROCFILE_STATIC is not None:
             start_composer(settings.PROCFILE_STATIC)
             _ = atexit.register(stop_composer, procfile=settings.PROCFILE_STATIC)
+
         super().run(**options)