fix: treat empty APIFY_ACTOR_PRICING_INFO env var as no pricing info

The platform sets APIFY_ACTOR_PRICING_INFO to `{}` for Actors without a
configured pricing model. The previous normalizer injected default
fields but left the `pricingModel` discriminator missing, causing the
apify-client pydantic union to fail with `union_tag_not_found` and every
Actor run to crash on startup with a ValidationError.

Treat an empty JSON object (and already-parsed non-dict values) as
"no pricing info" so the union resolves to `None`, matching the pre-v3
behavior where `data or None` handled the same case.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: vdusek

src/apify/_configuration.py

@@ -76,13 +76,20 @@ def _normalize_actor_pricing_info(data: Any) -> Any:
 
     The platform-provided env var omits some fields that are required by the apify-client pydantic models
     (`apifyMarginPercentage`, `createdAt`, `startedAt`, and per-event `eventDescription`). Inject safe
-    defaults for those so validation succeeds on the Actor side.
+    defaults for those so validation succeeds on the Actor side. Treat an empty env value or an empty/
+    discriminator-less JSON object as "no pricing info" to match the platform's behavior for Actors
+    without a configured pricing model.
     """
     if data is None or data == '':
         return None
     pricing_info = json.loads(data) if isinstance(data, str) else data
     if not isinstance(pricing_info, dict):
+        # Already a parsed pydantic model (or some other non-dict) - pass through for pydantic to validate.
         return pricing_info
+    if not pricing_info.get('pricingModel'):
+        # Platform sets `APIFY_ACTOR_PRICING_INFO={}` for Actors without a configured pricing model;
+        # without the discriminator, treat it as absent rather than letting the pydantic union fail.
+        return None
 
     pricing_info.setdefault('apifyMarginPercentage', 0.0)
     pricing_info.setdefault('createdAt', '1970-01-01T00:00:00.000Z')

tests/unit/actor/test_configuration.py

@@ -362,6 +362,17 @@ def test_actor_pricing_info_env_var_tolerates_platform_omissions(monkeypatch: py
     assert config.actor_pricing_info.pricing_model == 'PAY_PER_EVENT'
 
 
+@pytest.mark.parametrize('env_value', ['', '{}'])
+def test_actor_pricing_info_env_var_empty_becomes_none(monkeypatch: pytest.MonkeyPatch, env_value: str) -> None:
+    """Platform sends `APIFY_ACTOR_PRICING_INFO={}` for Actors without a pricing model.
+
+    Without a `pricingModel` discriminator, the pydantic union cannot resolve — treat it as no pricing info.
+    """
+    monkeypatch.setenv('APIFY_ACTOR_PRICING_INFO', env_value)
+    config = ApifyConfiguration()
+    assert config.actor_pricing_info is None
+
+
 def test_actor_storage_json_env_var(monkeypatch: pytest.MonkeyPatch) -> None:
     """Test that actor_storages_json is parsed from JSON env var."""
     datasets = {'default': 'default_dataset_id', 'custom': 'custom_dataset_id'}