Drop database between tests instead of removing collections.

Author: nlutsenko

spec/helper.js

@@ -227,7 +227,7 @@ function mockFacebook() {
 function clearData() {
   var promises = [];
   for (var conn in DatabaseAdapter.dbConnections) {
-    promises.push(DatabaseAdapter.dbConnections[conn].deleteEverything());
+    promises.push(DatabaseAdapter.dbConnections[conn].dropDatabase());
   }
   return Promise.all(promises);
 }

src/ExportAdapter.js

@@ -364,14 +364,21 @@ ExportAdapter.prototype.deleteEverything = function() {
     var promises = [];
     for (var coll of colls) {
       if (!coll.namespace.match(/\.system\./) &&
-          coll.collectionName.indexOf(this.collectionPrefix) === 0) {
+        coll.collectionName.indexOf(this.collectionPrefix) === 0) {
         promises.push(coll.drop());
       }
     }
     return Promise.all(promises);
   });
 };
 
+ExportAdapter.prototype.dropDatabase = () => {
+  this.schemaPromise = null;
+  return this.connect().then(() => {
+    return this.db.dropDatabase();
+  });
+};
+
 // Finds the keys in a query. Returns a Set. REST format only
 function keysForQuery(query) {
   var sublist = query['$and'] || query['$or'];