feat(NODE-6494): add support for hint on distinct commands

src/operations/distinct.ts

@@ -8,7 +8,20 @@ import { CommandOperation, type CommandOperationOptions } from './command';
 import { Aspect, defineAspects } from './operation';
 
 /** @public */
-export type DistinctOptions = CommandOperationOptions;
+export type DistinctOptions = CommandOperationOptions & {
+  /**
+   * @sinceServerVersion 7.1
+   *
+   * The index to use. Specify either the index name as a string or the index key pattern.
+   * If specified, then the query system will only consider plans using the hinted index.
+   *
+   * If provided as a string, `hint` must be index name for an index on the collection.
+   * If provided as an object, `hint` must be an index description for an index defined on the collection.
+   *
+   * See https://www.mongodb.com/docs/manual/reference/command/distinct/#command-fields.
+   */
+  hint?: Document | string;
+};
 
 /**
  * Return a list of distinct values for the given key across a collection.
@@ -71,6 +84,10 @@ export class DistinctOperation extends CommandOperation<any[]> {
       cmd.comment = options.comment;
     }
 
+    if (options.hint != null) {
+      cmd.hint = options.hint;
+    }
+
     // Do we have a readConcern specified
     decorateWithReadConcern(cmd, coll, options);
 

test/spec/crud/unified/distinct-hint.json

@@ -0,0 +1,139 @@
+{
+  "description": "distinct-hint",
+  "schemaVersion": "1.0",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "7.1.0"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0",
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "distinct-hint-tests"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection0",
+        "database": "database0",
+        "collectionName": "coll0"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll0",
+      "databaseName": "distinct-hint-tests",
+      "documents": [
+        {
+          "_id": 1,
+          "x": 11
+        },
+        {
+          "_id": 2,
+          "x": 22
+        },
+        {
+          "_id": 3,
+          "x": 33
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "distinct with hint string",
+      "operations": [
+        {
+          "name": "distinct",
+          "object": "collection0",
+          "arguments": {
+            "fieldName": "x",
+            "filter": {
+              "_id": 1
+            },
+            "hint": "_id_"
+          },
+          "expectResult": [
+            11
+          ]
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "distinct": "coll0",
+                  "key": "x",
+                  "query": {
+                    "_id": 1
+                  },
+                  "hint": "_id_"
+                },
+                "commandName": "distinct",
+                "databaseName": "distinct-hint-tests"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "distinct with hint document",
+      "operations": [
+        {
+          "name": "distinct",
+          "object": "collection0",
+          "arguments": {
+            "fieldName": "x",
+            "filter": {
+              "_id": 1
+            },
+            "hint": {
+              "_id": 1
+            }
+          },
+          "expectResult": [
+            11
+          ]
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "distinct": "coll0",
+                  "key": "x",
+                  "query": {
+                    "_id": 1
+                  },
+                  "hint": {
+                    "_id": 1
+                  }
+                },
+                "commandName": "distinct",
+                "databaseName": "distinct-hint-tests"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/spec/crud/unified/distinct-hint.yml

@@ -0,0 +1,73 @@
+description: "distinct-hint"
+
+schemaVersion: "1.0"
+runOnRequirements:
+  # https://jira.mongodb.org/browse/SERVER-14227
+  # Server supports distinct with hint starting from 7.1.0.
+  - minServerVersion: "7.1.0"
+
+createEntities:
+  - client:
+      id: &client0 client0
+      observeEvents: [ commandStartedEvent ]
+  - database:
+      id: &database0 database0
+      client: *client0
+      databaseName: &database0Name distinct-hint-tests
+  - collection:
+      id: &collection0 collection0
+      database: *database0
+      collectionName: &collection0Name coll0
+
+initialData:
+  - collectionName: *collection0Name
+    databaseName: *database0Name
+    documents:
+      - { _id: 1, x: 11 }
+      - { _id: 2, x: 22 }
+      - { _id: 3, x: 33 }
+
+tests:
+  - description: "distinct with hint string"
+    operations:
+      - name: distinct
+        object: *collection0
+        arguments:
+          fieldName: &fieldName x
+          filter: &filter { _id: 1 }
+          hint: _id_
+        expectResult: [ 11 ]
+    expectEvents:
+      - client: *client0
+        events:
+          - commandStartedEvent:
+              command:
+                distinct: *collection0Name
+                key: *fieldName
+                query: *filter
+                hint: _id_
+              commandName: distinct
+              databaseName: *database0Name
+
+  - description: "distinct with hint document"
+    operations:
+      - name: distinct
+        object: *collection0
+        arguments:
+          fieldName: *fieldName
+          filter: *filter
+          hint:
+            _id: 1
+        expectResult: [ 11 ]
+    expectEvents:
+      - client: *client0
+        events:
+          - commandStartedEvent:
+              command:
+                distinct: *collection0Name
+                key: *fieldName
+                query: *filter
+                hint:
+                  _id: 1
+              commandName: distinct
+              databaseName: *database0Name