Skip previous validation on pre/post load/dump (#1942)

* Build out the dataclasses for a base entry and version lock explicitly
* Ensure previous field does not have a nested previous
* Test validation on version lock for previous fields.

detection_rules/version_lock.py

@@ -24,16 +24,18 @@ MIN_LOCK_VERSION_DEFAULT = Version("7.13.0")
 
 
 @dataclass(frozen=True)
-class VersionLockFileEntry(MarshmallowDataclassMixin):
-    """Schema for a rule entry in the version lock."""
+class BaseEntry:
     rule_name: definitions.RuleName
     sha256: definitions.Sha256
     type: definitions.RuleType
     version: definitions.PositiveInteger
-    min_stack_version: Optional[definitions.SemVer]
 
-    # TODO: need to exclude nested 'previous'
-    previous: Optional[Dict[definitions.SemVer, 'VersionLockFileEntry']]
+
+@dataclass(frozen=True)
+class VersionLockFileEntry(MarshmallowDataclassMixin, BaseEntry):
+    """Schema for a rule entry in the version lock."""
+    min_stack_version: Optional[definitions.SemVer]
+    previous: Optional[Dict[definitions.SemVer, BaseEntry]]
 
 
 @dataclass(frozen=True)

tests/test_schemas.py

@@ -9,12 +9,13 @@ import unittest
 import uuid
 
 import eql
-
 from detection_rules import utils
 from detection_rules.packaging import load_current_package_version
 from detection_rules.rule import TOMLRuleContents
 from detection_rules.schemas import downgrade
 from detection_rules.semver import Version
+from detection_rules.version_lock import VersionLockFile
+from marshmallow import ValidationError
 
 
 class TestSchemas(unittest.TestCase):
@@ -236,6 +237,49 @@ class TestSchemas(unittest.TestCase):
             """)
 
 
+class TestVersionLockSchema(unittest.TestCase):
+    """Test that the version lock has proper entries."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.version_lock_contents = {
+            "33f306e8-417c-411b-965c-c2812d6d3f4d": {
+                "rule_name": "Remote File Download via PowerShell",
+                "sha256": "8679cd72bf85b67dde3dcfdaba749ed1fa6560bca5efd03ed41c76a500ce31d6",
+                "type": "eql",
+                "version": 4
+            },
+            "34fde489-94b0-4500-a76f-b8a157cf9269": {
+                "min_stack_version": "8.2",
+                "previous": {
+                    "7.13.0": {
+                        "rule_name": "Telnet Port Activity",
+                        "sha256": "3dd4a438c915920e6ddb0a5212603af5d94fb8a6b51a32f223d930d7e3becb89",
+                        "type": "query",
+                        "version": 9
+                    }
+                },
+                "rule_name": "Telnet Port Activity",
+                "sha256": "b0bdfa73639226fb83eadc0303ad1801e0707743f96a36209aa58228d3bf6a89",
+                "type": "query",
+                "version": 10
+            }
+        }
+
+    def test_version_lock_no_previous(self):
+        """Pass field validation on version lock without nested previous fields"""
+        version_lock_contents = copy.deepcopy(self.version_lock_contents)
+        VersionLockFile.from_dict(dict(data=version_lock_contents))
+
+    def test_version_lock_has_nested_previous(self):
+        """Fail field validation on version lock with nested previous fields"""
+        version_lock_contents = copy.deepcopy(self.version_lock_contents)
+        with self.assertRaises(ValidationError):
+            previous = version_lock_contents["34fde489-94b0-4500-a76f-b8a157cf9269"]["previous"]
+            version_lock_contents["34fde489-94b0-4500-a76f-b8a157cf9269"]["previous"]["previous"] = previous
+            VersionLockFile.from_dict(dict(data=version_lock_contents))
+
+
 class TestVersions(unittest.TestCase):
     """Test that schema versioning aligns."""