fix(NODE-4273): pass 'comment' option through to distinct command

src/operations/distinct.ts

@@ -1,9 +1,8 @@
 import type { Document } from '../bson';
 import type { Collection } from '../collection';
-import { MongoCompatibilityError } from '../error';
 import type { Server } from '../sdam/server';
 import type { ClientSession } from '../sessions';
-import { Callback, decorateWithCollation, decorateWithReadConcern, maxWireVersion } from '../utils';
+import { Callback, decorateWithCollation, decorateWithReadConcern } from '../utils';
 import { CommandOperation, CommandOperationOptions } from './command';
 import { Aspect, defineAspects } from './operation';
 
@@ -61,6 +60,12 @@ export class DistinctOperation extends CommandOperation<any[]> {
       cmd.maxTimeMS = options.maxTimeMS;
     }
 
+    // we check for undefined specifically here to allow falsy values
+    // eslint-disable-next-line no-restricted-syntax
+    if (typeof options.comment !== 'undefined') {
+      cmd.comment = options.comment;
+    }
+
     // Do we have a readConcern specified
     decorateWithReadConcern(cmd, coll, options);
 
@@ -71,13 +76,6 @@ export class DistinctOperation extends CommandOperation<any[]> {
       return callback(err);
     }
 
-    if (this.explain && maxWireVersion(server) < 4) {
-      callback(
-        new MongoCompatibilityError(`Server ${server.name} does not support explain on distinct`)
-      );
-      return;
-    }
-
     super.executeCommand(server, session, cmd, (err, result) => {
       if (err) {
         callback(err);

test/integration/node-specific/comment_with_falsy_values.test.ts

@@ -1,4 +1,6 @@
-import { Long } from '../../../src';
+import { expect } from 'chai';
+
+import { Collection, CommandStartedEvent, Long, MongoClient } from '../../../src';
 import { TestBuilder, UnifiedTestSuiteBuilder } from '../../tools/utils';
 
 const falsyValues = [0, false, '', Long.ZERO, null, NaN] as const;
@@ -173,4 +175,39 @@ describe('Comment with falsy values', () => {
     .test(testsForChangeStreamsAggregate)
     .test(testsForGetMore)
     .run();
+
+  context('Collection.distinct()', function () {
+    let client: MongoClient;
+    let collection: Collection;
+    let commands: CommandStartedEvent[] = [];
+
+    beforeEach(async function () {
+      client = this.configuration.newClient({ monitorCommands: true });
+      client.on('commandStarted', e => commands.push(e));
+      await client.connect();
+      collection = await client.db('comment-falsy-values').createCollection('collection');
+      commands = [];
+    });
+
+    afterEach(async function () {
+      await collection.drop();
+      await client.close();
+    });
+
+    for (const falsyValue of falsyValues) {
+      it(`distinct should send falsy value ${falsyToString(
+        falsyValue
+      )} on the command`, async function () {
+        await collection.distinct('some-key', {}, { comment: falsyValue }).catch(() => null);
+
+        expect(commands).to.have.lengthOf(1);
+        const distinctCommand = commands.find(command => command.commandName === 'distinct');
+        expect(distinctCommand).to.exist;
+
+        // chai does not narrow types, so TS doesn't know the distinct command exists at this point.
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+        expect(distinctCommand!.command).to.haveOwnProperty('comment');
+      });
+    }
+  });
 });

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

@@ -0,0 +1,186 @@
+{
+  "description": "distinct-comment",
+  "schemaVersion": "1.0",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0",
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "distinct-comment-tests"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection0",
+        "database": "database0",
+        "collectionName": "coll0"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll0",
+      "databaseName": "distinct-comment-tests",
+      "documents": [
+        {
+          "_id": 1,
+          "x": 11
+        },
+        {
+          "_id": 2,
+          "x": 22
+        },
+        {
+          "_id": 3,
+          "x": 33
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "distinct with document comment",
+      "runOnRequirements": [
+        {
+          "minServerVersion": "4.4.14"
+        }
+      ],
+      "operations": [
+        {
+          "name": "distinct",
+          "object": "collection0",
+          "arguments": {
+            "fieldName": "x",
+            "filter": {},
+            "comment": {
+              "key": "value"
+            }
+          },
+          "expectResult": [
+            11,
+            22,
+            33
+          ]
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "distinct": "coll0",
+                  "key": "x",
+                  "query": {},
+                  "comment": {
+                    "key": "value"
+                  }
+                },
+                "commandName": "distinct",
+                "databaseName": "distinct-comment-tests"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "distinct with string comment",
+      "runOnRequirements": [
+        {
+          "minServerVersion": "4.4.0"
+        }
+      ],
+      "operations": [
+        {
+          "name": "distinct",
+          "object": "collection0",
+          "arguments": {
+            "fieldName": "x",
+            "filter": {},
+            "comment": "comment"
+          },
+          "expectResult": [
+            11,
+            22,
+            33
+          ]
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "distinct": "coll0",
+                  "key": "x",
+                  "query": {},
+                  "comment": "comment"
+                },
+                "commandName": "distinct",
+                "databaseName": "distinct-comment-tests"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "distinct with document comment - pre 4.4, server error",
+      "runOnRequirements": [
+        {
+          "minServerVersion": "3.6.0",
+          "maxServerVersion": "4.4.13"
+        }
+      ],
+      "operations": [
+        {
+          "name": "distinct",
+          "object": "collection0",
+          "arguments": {
+            "fieldName": "x",
+            "filter": {},
+            "comment": {
+              "key": "value"
+            }
+          },
+          "expectError": {
+            "isClientError": false
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "distinct": "coll0",
+                  "key": "x",
+                  "query": {},
+                  "comment": {
+                    "key": "value"
+                  }
+                },
+                "commandName": "distinct",
+                "databaseName": "distinct-comment-tests"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

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

@@ -0,0 +1,98 @@
+description: "distinct-comment"
+
+schemaVersion: "1.0"
+
+createEntities:
+  - client:
+      id: &client0 client0
+      observeEvents: [ commandStartedEvent ]
+  - database:
+      id: &database0 database0
+      client: *client0
+      databaseName: &database0Name distinct-comment-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 document comment"
+    runOnRequirements:
+      # https://jira.mongodb.org/browse/SERVER-44847
+      # Server supports distinct with comment of any type for comment starting from 4.4.14.
+      - minServerVersion: "4.4.14"
+    operations:
+      - name: distinct
+        object: *collection0
+        arguments:
+          fieldName: &fieldName x
+          filter: &filter {}
+          comment: &documentComment { key: "value"}
+        expectResult: [ 11, 22, 33 ]
+    expectEvents:
+      - client: *client0
+        events:
+          - commandStartedEvent:
+              command:
+                distinct: *collection0Name
+                key: *fieldName
+                query: *filter
+                comment: *documentComment
+              commandName: distinct
+              databaseName: *database0Name
+
+  - description: "distinct with string comment"
+    runOnRequirements:
+      - minServerVersion: "4.4.0"
+    operations:
+      - name: distinct
+        object: *collection0
+        arguments:
+          fieldName: *fieldName
+          filter: *filter
+          comment: &stringComment "comment"
+        expectResult: [ 11, 22, 33 ]
+    expectEvents:
+      - client: *client0
+        events:
+          - commandStartedEvent:
+              command:
+                distinct: *collection0Name
+                key: *fieldName
+                query: *filter
+                comment: *stringComment
+              commandName: distinct
+              databaseName: *database0Name
+
+  - description: "distinct with document comment - pre 4.4, server error"
+    runOnRequirements:
+      - minServerVersion: "3.6.0"
+        maxServerVersion: "4.4.13"
+    operations:
+      - name: distinct
+        object: *collection0
+        arguments:
+          fieldName: *fieldName
+          filter: *filter
+          comment: *documentComment
+        expectError:
+          isClientError: false
+    expectEvents:
+      - client: *client0
+        events:
+          - commandStartedEvent:
+              command:
+                distinct: *collection0Name
+                key: *fieldName
+                query: *filter
+                comment: *documentComment
+              commandName: distinct
+              databaseName: *database0Name