throw error for empty asset key (#8069)

dagster-io · May 25, 2022 · ac6007c · ac6007c
1 parent 84ccc32
commit ac6007c
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diff --git a/python_modules/dagster/dagster/core/definitions/events.py b/python_modules/dagster/dagster/core/definitions/events.py
@@ -87,6 +87,9 @@ def __new__(cls, path: Sequence[str]):
         else:
             path = list(check.sequence_param(path, "path", of_type=str))
 
+        check.invariant(
+            all(len(seg) > 0 for seg in path), "Asset key segments must be non-empty strings."
+        )
         return super(AssetKey, cls).__new__(cls, path=path)
 
     def __str__(self):

diff --git a/python_modules/dagster/dagster_tests/core_tests/storage_tests/test_assets.py b/python_modules/dagster/dagster_tests/core_tests/storage_tests/test_assets.py
@@ -1,4 +1,7 @@
+import pytest
+
 from dagster import AssetKey, AssetMaterialization, Output, job, op
+from dagster._check import CheckError
 from dagster.core.definitions.events import parse_asset_key_string
 from dagster.core.events.log import EventLogEntry
 from dagster.core.instance import DagsterInstance, InstanceRef
@@ -7,6 +10,13 @@
 from dagster.utils.test import copy_directory
 
 
+def test_invalid_asset_key():
+    with pytest.raises(CheckError):
+        AssetKey("")
+    with pytest.raises(CheckError):
+        AssetKey(["foo", "", "bar"])
+
+
 def test_structured_asset_key():
     asset_parsed = AssetKey(parse_asset_key_string("(Hello)"))
     assert len(asset_parsed.path) == 1