feat(shared): add helper utilities for assertion and suite setup

NODE-1095

Author: mbroadst

test/functional/shared.js

@@ -1,4 +1,5 @@
-var MongoClient = require('../../').MongoClient;
+var MongoClient = require('../../').MongoClient,
+  expect = require('chai').expect;
 
 function connectToDb(url, db, options, callback) {
   if (typeof options === 'function') {
@@ -12,6 +13,30 @@ function connectToDb(url, db, options, callback) {
   });
 }
 
+function setupDatabase(configuration) {
+  var dbName = configuration.db;
+  var client = configuration.newClient(configuration.writeConcernMax(), {
+    poolSize: 1
+  });
+
+  return client.connect().then(function() {
+    var db = client.db(dbName);
+    return db.dropDatabase();
+  });
+}
+
+var assert = {
+  equal: function(a, b) {
+    expect(a).to.equal(b);
+  },
+
+  ok: function(a) {
+    expect(a).to.be.ok;
+  }
+};
+
 module.exports = {
-  connectToDb: connectToDb
+  connectToDb: connectToDb,
+  setupDatabase: setupDatabase,
+  assert: assert
 };