fix(mongodb): decode extended JSON document ids

agents/drivers/mongodb/src/main/java/com/dbx/agent/mongodb/MongoAgent.java

@@ -641,12 +641,9 @@ public final class MongoAgent {
             return stringId;
         }
         String trimmed = id.trim();
-        if (isNumberLongIdWrapper(trimmed)) {
-            try {
-                return Document.parse("{\"_id\":" + trimmed + "}").get("_id");
-            } catch (Exception e) {
-                // Fall through to the legacy ObjectId/string handling below.
-            }
+        Object extendedJsonId = parseExtendedJsonId(trimmed);
+        if (extendedJsonId != null) {
+            return extendedJsonId;
         }
         try {
             return new ObjectId(id);
@@ -668,20 +665,21 @@ public final class MongoAgent {
         }
     }
 
-    private static boolean isNumberLongIdWrapper(String value) {
+    private static Object parseExtendedJsonId(String value) {
         try {
             JsonElement parsed = JsonParser.parseString(value);
             if (!parsed.isJsonObject()) {
-                return false;
+                return null;
             }
             JsonObject wrapper = parsed.getAsJsonObject();
-            JsonElement numberLong = wrapper.get("$numberLong");
-            return wrapper.size() == 1
-                && numberLong != null
-                && numberLong.isJsonPrimitive()
-                && numberLong.getAsJsonPrimitive().isString();
+            if (wrapper.size() != 1 || (!wrapper.has("$oid") && !wrapper.has("$numberLong"))) {
+                return null;
+            }
+            // The document browser preserves BSON _id types as Extended JSON;
+            // decode only known wrappers so JSON-looking string IDs stay strings.
+            return Document.parse("{\"_id\":" + value + "}").get("_id");
         } catch (Exception e) {
-            return false;
+            return null;
         }
     }
 
@@ -698,9 +696,22 @@ public final class MongoAgent {
         var result = isUpdateOperatorDocument(newDoc)
             ? col.updateOne(filter, newDoc)
             : col.replaceOne(filter, replacementDocument(newDoc));
+        requireMatchedDocument(id, result);
         return Collections.singletonMap("modified_count", result.getModifiedCount());
     }
 
+    static void requireMatchedDocument(String id, UpdateResult result) {
+        if (result.getMatchedCount() == 0) {
+            throw new IllegalStateException(noMatchingDocumentError(id));
+        }
+    }
+
+    private static String noMatchingDocumentError(String id) {
+        String display = decodeStringDocumentId(id);
+        return "No document matched _id " + (display == null ? id : display)
+            + ". It may have been deleted or its _id changed since the query ran.";
+    }
+
     private static Object updateDocuments(JsonObject params) {
         MongoClient c = requireClient();
         String database = params.get("database").getAsString();

agents/drivers/mongodb/src/test/java/com/dbx/agent/mongodb/MongoAgentTest.java

@@ -179,10 +179,12 @@ class MongoAgentTest {
     void preservesLongDocumentIdTypeForGridUpdates() {
         Object id = MongoAgent.convertDocumentFieldValue("_id", 2_048_938_405_781_032_962L);
         Object value = MongoAgent.convertDocumentFieldValue("snowflake", 2_048_938_405_781_032_962L);
+        ObjectId objectId = new ObjectId("507f1f77bcf86cd799439011");
 
         assertEquals(Collections.singletonMap("$numberLong", "2048938405781032962"), id);
         assertEquals("2048938405781032962", value);
         assertEquals(2_048_938_405_781_032_962L, MongoAgent.parseId("{\"$numberLong\":\"2048938405781032962\"}"));
+        assertEquals(objectId, MongoAgent.parseId("{\"$oid\":\"507f1f77bcf86cd799439011\"}"));
     }
 
     @Test
@@ -196,6 +198,23 @@ class MongoAgentTest {
         assertEquals("{\"$numberLong\":\"invalid\"}", MongoAgent.parseId("{\"$numberLong\":\"invalid\"}"));
     }
 
+    @Test
+    void documentUpdateDistinguishesNoMatchFromUnchangedValue() {
+        MongoAgent.requireMatchedDocument(
+            "{\"$oid\":\"507f1f77bcf86cd799439011\"}",
+            UpdateResult.acknowledged(1, 0L, null)
+        );
+
+        IllegalStateException error = assertThrows(
+            IllegalStateException.class,
+            () -> MongoAgent.requireMatchedDocument(
+                "{\"$oid\":\"507f1f77bcf86cd799439012\"}",
+                UpdateResult.acknowledged(0, 0L, null)
+            )
+        );
+        assertTrue(error.getMessage().startsWith("No document matched _id"));
+    }
+
     @Test
     void serverVersionMethodIsRecognizedOverJsonRpc() {
         String response = MongoAgent.handleRequest(