docs: adding aggregation, createIndex, and runCommand examples

Fixes NODE-1323

test/examples/aggregate.js

@@ -0,0 +1,140 @@
+'use strict';
+
+const setupDatabase = require('../functional/shared').setupDatabase;
+const MongoClient = require('../../lib/mongo_client');
+
+describe('examples.aggregaton:', function() {
+  let client;
+  let collection;
+
+  before(async function() {
+    await setupDatabase(this.configuration);
+  });
+
+  beforeEach(async function() {
+    client = await MongoClient.connect(this.configuration.url());
+    collection = client.db(this.configuration.db).collection('aggregateExample');
+  });
+
+  afterEach(async function() {
+    await client.close();
+    client = undefined;
+    collection = undefined;
+  });
+
+  it('supports simple aggregation', {
+    metadata: { requires: { mongodb: '>=2.8.0', topology: ['single'] } },
+    test: async function() {
+      // Start aggregate example 1
+      await collection
+        .aggregate([{ $match: { 'items.fruit': 'banana' } }, { $sort: { date: 1 } }])
+        .toArray();
+      // End aggregate example 1
+    }
+  });
+
+  it('supports $match, $group, $project, $unwind, $sum, $sort, $dayOfWeek', {
+    metadata: { requires: { mongodb: '>=2.8.0', topology: ['single'] } },
+    test: async function() {
+      // Start aggregate example 2
+      await collection
+        .aggregate([
+          {
+            $unwind: '$items'
+          },
+          {
+            $match: {
+              'items.fruit': 'banana'
+            }
+          },
+          {
+            $group: {
+              _id: { day: { $dayOfWeek: '$date' } },
+              count: { $sum: '$items.quantity' }
+            }
+          },
+          {
+            $project: {
+              dayOfWeek: '$_id.day',
+              numberSold: '$count',
+              _id: 0
+            }
+          },
+          {
+            $sort: { numberSold: 1 }
+          }
+        ])
+        .toArray();
+      // End aggregate example 2
+    }
+  });
+
+  it('supports $unwind, $group, $sum, $dayOfWeek, $multiply, $project, $cond', {
+    metadata: { requires: { mongodb: '>=2.8.0', topology: ['single'] } },
+    test: async function() {
+      // Start aggregate example 3
+      await collection
+        .aggregate([
+          {
+            $unwind: '$items'
+          },
+          {
+            $group: {
+              _id: { day: { $dayOfWeek: '$date' } },
+              items_sold: { $sum: '$items.quantity' },
+              revenue: { $sum: { $multiply: ['$items.quantity', '$items.price'] } }
+            }
+          },
+          {
+            $project: {
+              day: '$_id.day',
+              revenue: 1,
+              items_sold: 1,
+              discount: {
+                $cond: { if: { $lte: ['$revenue', 250] }, then: 25, else: 0 }
+              }
+            }
+          }
+        ])
+        .toArray();
+      // End aggregate example 3
+    }
+  });
+
+  it('supports $lookup, $filter, $match', {
+    metadata: { requires: { mongodb: '>=2.8.0', topology: ['single'] } },
+    test: async function() {
+      // Start aggregate example 4
+      await collection
+        .aggregate([
+          {
+            $lookup: {
+              from: 'air_airlines',
+              let: { constituents: '$airlines' },
+              pipeline: [
+                {
+                  $match: { $expr: { $in: ['$name', '$$constituents'] } }
+                }
+              ],
+              as: 'airlines'
+            }
+          },
+          {
+            $project: {
+              _id: 0,
+              name: 1,
+              airlines: {
+                $filter: {
+                  input: '$airlines',
+                  as: 'airline',
+                  cond: { $eq: ['$$airline.country', 'Canada'] }
+                }
+              }
+            }
+          }
+        ])
+        .toArray();
+      // End aggregate example 4
+    }
+  });
+});

test/examples/create_index.js

@@ -0,0 +1,45 @@
+'use strict';
+
+const setupDatabase = require('../functional/shared').setupDatabase;
+const MongoClient = require('../../lib/mongo_client');
+
+describe('examples.createIndex:', function() {
+  let client;
+  let collection;
+
+  before(async function() {
+    await setupDatabase(this.configuration);
+  });
+
+  beforeEach(async function() {
+    client = await MongoClient.connect(this.configuration.url());
+    collection = client.db(this.configuration.db).collection('createIndexExample');
+  });
+
+  afterEach(async function() {
+    await client.close();
+    client = undefined;
+    collection = undefined;
+  });
+
+  it('supports building simple ascending index', {
+    metadata: { requires: { topology: ['single'] } },
+    test: async function() {
+      // Start createIndex example 1
+      await collection.createIndex({ score: 1 });
+      // End createIndex example 1
+    }
+  });
+
+  it('supports building multikey index with partial filter expression', {
+    metadata: { requires: { topology: ['single'], mongodb: '>=3.2.x' } },
+    test: async function() {
+      // Start createIndex example 2
+      await collection.createIndex(
+        { cuisine: 1, name: 1 },
+        { partialFilterExpression: { rating: { $gt: 5 } } }
+      );
+      // End createIndex example 2
+    }
+  });
+});

test/examples/run_command.js

@@ -0,0 +1,45 @@
+'use strict';
+
+const setupDatabase = require('../functional/shared').setupDatabase;
+const MongoClient = require('../../lib/mongo_client');
+
+describe('examples.runCommand:', function() {
+  let client;
+  let db;
+
+  before(async function() {
+    await setupDatabase(this.configuration);
+  });
+
+  beforeEach(async function() {
+    client = await MongoClient.connect(this.configuration.url());
+    db = client.db(this.configuration.db);
+
+    // Done to ensure existence of collection
+    await db.collection('restaurants').insertOne({});
+  });
+
+  afterEach(async function() {
+    await client.close();
+    client = undefined;
+    db = undefined;
+  });
+
+  it('supports runCommand 1', {
+    metadata: { requires: { topology: ['single'] } },
+    test: async function() {
+      // Start runCommand example 1
+      await db.command({ buildInfo: 1 });
+      // End runCommand example 1
+    }
+  });
+
+  it('supports runCommand 2', {
+    metadata: { requires: { topology: ['single'] } },
+    test: async function() {
+      // Start runCommand example 2
+      await db.command({ collStats: 'restaurants' });
+      // End runCommand example 2
+    }
+  });
+});