cursor: Fix count function on aggregation cursor

README.md

@@ -23,7 +23,7 @@ Notable Changes
 
 Upgrade main steps
 
-- `yarn remove @neo9/n9-mongo-client && yarn add @neo9/n9-mongodb-client@^1.0.0-rc.2` (this also upgrade all transitive dependencies)
+- `yarn remove @neo9/n9-mongo-client && yarn add @neo9/n9-mongodb-client@^1.0.0-rc.8` (this also upgrade all transitive dependencies)
 - Rename usage : `find src/ -type f -exec sed -i -e 's#@neo9/n9-mongo-client#@neo9/n9-mongodb-client#g' {} +`
 - Remove old mongodb types :
 
@@ -44,6 +44,8 @@ Upgrade main steps
 - Upgrade MongoDb used for tests to version 6.0+
 - Change MongoDB types imports from `import ... from 'mongodb';` to `import ... from '@neo9/n9-mongodb-client/mongodb';`
 - Use Node.js version 16.20.2 or greater.
+- Use new `count` function on `N9AggregationCursor` that wasn't available on `AggregationCursor`
+- It's a good time to use new version of `@neo9/n9-mongodb-migration` V1 : `yarn upgrade @neo9/n9-mongodb-migration@^1.0.0-rc.0`
 
 ## To build
 

src/client.ts

@@ -1050,10 +1050,14 @@ export class MongoClient<U extends BaseMongoObject, L extends BaseMongoObject> {
 	): N9AggregationCursor<T> {
 		if (readInOutputCollection) {
 			const nativeCursor = this.collection.aggregate<T>(aggregateSteps, options);
-			return new N9AggregationCursor<T>(this.collection, nativeCursor);
+			return new N9AggregationCursor<T>(this.collection, nativeCursor, aggregateSteps);
 		}
 		const nativeCursor = this.collectionSourceForAggregation.aggregate<T>(aggregateSteps, options);
-		return new N9AggregationCursor<T>(this.collectionSourceForAggregation, nativeCursor);
+		return new N9AggregationCursor<T>(
+			this.collectionSourceForAggregation,
+			nativeCursor,
+			aggregateSteps,
+		);
 	}
 
 	public aggregateWithBuilder<T = void>(

src/cursors/n9-aggregation-cursor.ts

@@ -1,30 +1,23 @@
-import { N9Error } from '@neo9/n9-node-utils';
-import * as _ from 'lodash';
-import { AggregationCursor, Collection, Filter } from 'mongodb';
+import { AggregationCursor, Collection } from 'mongodb';
 
+import { LodashReplacerUtils } from '../lodash-replacer.utils';
 import { N9AbstractCursor } from './n9-abstract-cursor';
 
 export class N9AggregationCursor<E> extends N9AbstractCursor<E> {
-	private _filterQuery: Filter<E>; // can be edited with filter function
-
 	public constructor(
 		private readonly collection: Collection<any>,
 		private readonly aggregationCursor: AggregationCursor<E>,
+		private readonly aggregateSteps: object[],
 	) {
 		super(aggregationCursor);
 	}
 
-	/**
-	 * Set the filterQuery used for count
-	 *
-	 * @param value
-	 */
-	set filterQuery(value: Filter<E>) {
-		this._filterQuery = value;
-	}
-
 	clone(): N9AggregationCursor<E> {
-		return new N9AggregationCursor<E>(this.collection, this.aggregationCursor.clone());
+		return new N9AggregationCursor<E>(
+			this.collection,
+			this.aggregationCursor.clone(),
+			this.aggregateSteps,
+		);
 	}
 
 	public async launch(): Promise<void> {
@@ -37,19 +30,23 @@ export class N9AggregationCursor<E> extends N9AbstractCursor<E> {
 	}
 
 	/**
-	 * Get the count of documents for this cursor using the filterQuery.
-	 *
-	 * @see filterQuery
+	 * Get the count of documents for this cursor.
 	 */
 	public async count(): Promise<number> {
-		if (!this._filterQuery) {
-			throw new N9Error('filter-query-not-initialized', 400, {
-				hint: 'Set filterQuery on the N9AggregationCursor before calling count function.',
-			});
-		}
-		if (_.isEmpty(this._filterQuery)) {
+		if (LodashReplacerUtils.IS_ARRAY_EMPTY(this.aggregateSteps)) {
 			return await this.collection.estimatedDocumentCount();
 		}
-		return await this.collection.countDocuments(this._filterQuery);
+		const countResult = await this.collection
+			.aggregate([
+				...this.aggregateSteps,
+				{
+					$group: {
+						_id: null,
+						n: { $sum: 1 },
+					},
+				},
+			])
+			.toArray();
+		return countResult[0].n;
 	}
 }

src/models/aggregate.models.ts

@@ -403,8 +403,8 @@ export interface GraphLookupPipelineStage {
 
 /* GROUP */
 export interface GroupPipelineStageValue {
-	_id: Expression;
-	[fieldName: string]: Expression;
+	_id: number | Expression;
+	[fieldName: string]: number | Expression;
 }
 export interface GroupPipelineStage {
 	[AggregationPipelineStageOperator.GROUP]: GroupPipelineStageValue;

src/mongo-utils.ts

@@ -27,6 +27,9 @@ export class MongoUtils {
 
 		const optionsWithDefaultValuesApplied: mongodb.MongoClientOptions = {
 			heartbeatFrequencyMS: 3_000,
+			driverInfo: {
+				name: '@neo9/n9-mongodb-client',
+			},
 			...options,
 		};
 

test/aggregation-cursor.test.ts

@@ -83,21 +83,18 @@ test('[Cursor] call hasNext before using in a for async', async (t: ExecutionCon
 
 test('[Cursor] Check count function', async (t: ExecutionContext<ContextContent>) => {
 	let cursor = t.context.mongoClient.aggregate<SampleType>([]);
-	cursor.filterQuery = {};
 	t.is(await cursor.count(), 5, 'cursor contains 5 items');
 
 	const filterQuery = { field1String: { $regex: /[24680]$/ } };
 	cursor = t.context.mongoClient.aggregateWithBuilder<SampleType>(
 		t.context.mongoClient.newAggregationBuilder().match(filterQuery),
 	);
+	t.is(await cursor.count(), 2, 'cursor contains only odd => 2 elements');
 
-	await t.throwsAsync(
-		async () => await cursor.count(),
-		{ message: 'filter-query-not-initialized' },
-		'Should throw filter query not initialized error',
+	cursor = t.context.mongoClient.aggregateWithBuilder<SampleType>(
+		t.context.mongoClient.newAggregationBuilder().match(filterQuery).group({ _id: 1 }),
 	);
-	cursor.filterQuery = filterQuery;
-	t.is(await cursor.count(), 2, 'cursor contains only odd => 2 elements');
+	t.is(await cursor.count(), 1, 'cursor only contains the group result');
 });
 
 test('[Cursor] Check cursor clone function', async (t: ExecutionContext<ContextContent>) => {