From e9ddcff58859e031706d1554cb1ae4dbd595ab97 Mon Sep 17 00:00:00 2001
From: Andreas Motl <andreas.motl@crate.io>
Date: Sun, 22 Sep 2024 04:07:58 +0200
Subject: [PATCH] MongoDB: Fix edge case when decoding MongoDB Extended JSON
 elements

---
 CHANGES.md                             | 1 +
 src/commons_codec/transform/mongodb.py | 2 +-
 tests/transform/mongodb/data.py        | 6 ++++--
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index f80ba3f..98ee265 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,7 @@
 # Changelog
 
 ## Unreleased
+- MongoDB: Fixed edge case when decoding MongoDB Extended JSON elements
 
 ## 2024/09/19 v0.0.16
 - MongoDB: Added `MongoDBFullLoadTranslator` and `MongoDBCrateDBConverter`
diff --git a/src/commons_codec/transform/mongodb.py b/src/commons_codec/transform/mongodb.py
index 3f19e85..69b6047 100644
--- a/src/commons_codec/transform/mongodb.py
+++ b/src/commons_codec/transform/mongodb.py
@@ -71,7 +71,7 @@ def decode_value(self, value: t.Any) -> t.Any:
         """
         if isinstance(value, dict):
             # Decode item in BSON CANONICAL format.
-            if len(value) == 1:
+            if len(value) == 1 and next(iter(value)).startswith("$"):
                 return self.decode_canonical(value)
 
             # Custom adjustments to compensate shape anomalies in source data.
diff --git a/tests/transform/mongodb/data.py b/tests/transform/mongodb/data.py
index ddcff7a..53e6265 100644
--- a/tests/transform/mongodb/data.py
+++ b/tests/transform/mongodb/data.py
@@ -55,7 +55,7 @@
     "canonical": {
         "code_ascii": {"$code": "abab"},
         "code_bytes": {"$code": "ab\u0000ab\u0000"},
-        "code_scope": {"$code": "abab", "$scope": {"x": {"$numberInt": 42}}},
+        "code_scope": {"$code": "abab", "$scope": {"x": {"$numberInt": "42"}}},
         "date_iso8601": {"$date": "2015-09-23T10:32:42.33Z"},
         "date_numberlong": {"$date": {"$numberLong": "1356351330000"}},
         "dbref": {
@@ -78,6 +78,7 @@
         ],
         "list_dict": [
             {"id": "bar", "value": {"$date": "2015-09-24T10:32:42.33Z"}},
+            {"value": {"$date": "2015-09-24T10:32:42.33Z"}},
         ],
         "list_int": [
             {"$numberInt": "-2147483648"},
@@ -163,7 +164,7 @@
         "code_scope": {
             "$code": "abab",
             "$scope": {
-                "x": {"$numberInt": 42},
+                "x": 42,
             },
         },
         "date_iso8601": 1443004362000,
@@ -187,6 +188,7 @@
         ],
         "list_dict": [
             {"id": "bar", "value": 1443090762000},
+            {"value": 1443090762000},
         ],
         "list_int": [
             -2147483648,