DRIVERS-3058 Include nsType field in ChangeStreamDocument (#1748)

Author: abr-egn

source/change-streams/change-streams.md

@@ -120,6 +120,16 @@ class ChangeStreamDocument {
    */
   ns: Document;
 
+  /**
+   * Only present for ops of type 'create'.
+   * Only present when the `showExpandedEvents` change stream option is enabled.
+   * 
+   * The type of the newly created object.
+   * 
+   * @since 8.1.0
+   */
+  nsType: "collection" | "timeseries" | "view" | null;
+
   /**
    * Only present for ops of type 'rename'.
    *
@@ -1006,6 +1016,8 @@ There should be no backwards compatibility concerns.
 
 ## Changelog
 
+- 2025-01-29: Add `nsType` to `ChangeStreamDocument`.
+
 - 2024-02-09: Migrated from reStructuredText to Markdown.
 
 - 2023-08-11: Update server versions for `$changeStreamSplitLargeEvent` test.

source/change-streams/tests/unified/change-streams-nsType.json

@@ -0,0 +1,86 @@
+description: "change-streams-nsType"
+schemaVersion: "1.7"
+runOnRequirements:
+  - minServerVersion: "8.1.0"
+    topologies: [ replicaset, sharded ]
+    serverless: forbid
+createEntities:
+  - client:
+      id: &client0 client0
+      useMultipleMongoses: false
+  - database:
+      id: &database0 database0
+      client: *client0
+      databaseName: *database0
+
+tests:
+  - description: "nsType is present when creating collections"
+    operations:
+      - name: dropCollection
+        object: *database0
+        arguments:
+          collection: &collection0 foo
+      - name: createChangeStream
+        object: *database0
+        arguments:
+          pipeline: []
+          showExpandedEvents: true
+        saveResultAsEntity: &changeStream0 changeStream0
+      - name: createCollection
+        object: *database0
+        arguments:
+          collection: *collection0
+      - name: iterateUntilDocumentOrError
+        object: *changeStream0
+        expectResult:
+          operationType: create
+          nsType: collection
+
+  - description: "nsType is present when creating timeseries"
+    operations:
+      - name: dropCollection
+        object: *database0
+        arguments:
+          collection: &collection0 foo
+      - name: createChangeStream
+        object: *database0
+        arguments:
+          pipeline: []
+          showExpandedEvents: true
+        saveResultAsEntity: &changeStream0 changeStream0
+      - name: createCollection
+        object: *database0
+        arguments:
+          collection: *collection0
+          timeseries:
+            timeField: "time"
+            metaField: "meta"
+            granularity: "minutes"
+      - name: iterateUntilDocumentOrError
+        object: *changeStream0
+        expectResult:
+          operationType: create
+          nsType: timeseries
+
+  - description: "nsType is present when creating views"
+    operations:
+      - name: dropCollection
+        object: *database0
+        arguments:
+          collection: &collection0 foo
+      - name: createChangeStream
+        object: *database0
+        arguments:
+          pipeline: []
+          showExpandedEvents: true
+        saveResultAsEntity: &changeStream0 changeStream0
+      - name: createCollection
+        object: *database0
+        arguments:
+          collection: *collection0
+          viewOn: testName
+      - name: iterateUntilDocumentOrError
+        object: *changeStream0
+        expectResult:
+          operationType: create
+          nsType: view