docs(NODE-5961): aggregate projection example 1 (#4040)

test/integration/node-specific/examples/project_fields_from_query_results.test.js

@@ -219,4 +219,45 @@ describe('examples(project-fields-from-query):', function () {
  });
  }
  });
+
+ it('Aggregation Projection Example 1', {
+ metadata: { requires: { mongodb: '>= 4.4.0' } },
+ test: async function () {
+ // Start Aggregation Projection Example 1
+ const cursor = db
+ .collection('inventory')
+ .find()
+ .project({
+ _id: 0,
+ item: 1,
+ status: {
+ $switch: {
+ branches: [
+ {
+ case: { $eq: ['$status', 'A'] },
+ then: 'Available'
+ },
+ {
+ case: { $eq: ['$status', 'D'] },
+ then: 'Discontinued'
+ }
+ ],
+ default: 'No status found'
+ }
+ },
+ area: {
+ $concat: [{ $toString: { $multiply: ['$size.h', '$size.w'] } }, ' ', '$size.uom']
+ },
+ reportNumber: { $literal: 1 }
+ });
+ // End Aggregation Projection Example 1
+ const docs = await cursor.toArray();
+ for (const doc of docs) {
+ expect(doc).to.have.all.keys(['item', 'status', 'area', 'reportNumber']);
+ expect(doc).to.not.have.property('_id');
+ expect(doc.area).to.be.a('string');
+ expect(doc.reportNumber).to.equal(1);
+ }
+ }
+ });
 });