Feature/estimated document count (#43)

* Add support for mongoose 'countDocuments' function

* Add support for mongoose 'estimatedDocumentCount' function

* Update doc

README.md

@@ -113,7 +113,9 @@ beforeEach(() => {
 
 - [x] `find` - for find query
 - [x] `findOne` - for findOne query
-- [x] `count` - for count query
+- [x] `count` - for count query (deprecated)
+- [x] `countDocuments` for count query
+- [x] `estimatedDocumentCount` for count collection documents
 - [x] `distinct` - for distinct query
 - [x] `findOneAndUpdate` - for findOneAndUpdate query
 - [x] `findOneAndRemove` - for findOneAndRemove query

___tests___/index.test.js

@@ -86,6 +86,24 @@ describe('mockingoose', () => {
 			});
 		});
 
+		it('should countDocuments', () => {
+			const count = 2;
+			mockingoose.User.toReturn(count, 'countDocuments');
+
+			return User.countDocuments().then(result => {
+				expect(result).toBe(count);
+			});
+		});
+
+		it('should estimatedDocumentCount', () => {
+			const count = 2;
+			mockingoose.User.toReturn(count, 'estimatedDocumentCount');
+
+			return User.estimatedDocumentCount().then(result => {
+				expect(result).toBe(count);
+			});
+		});
+
 		it('should count exec and cb', (done) => {
 			const count = 2;
 			mockingoose.User.toReturn(count, 'count');
@@ -98,6 +116,30 @@ describe('mockingoose', () => {
 				});
 		});
 
+		it('should countDocuments exec and cb', (done) => {
+			const count = 2;
+			mockingoose.User.toReturn(count, 'countDocuments');
+
+			User
+				.countDocuments()
+				.exec((err, result) => {
+					expect(result).toBe(count);
+					done();
+				});
+		});
+
+		it('should estimatedDocumentCount exec and cb', (done) => {
+			const count = 2;
+			mockingoose.User.toReturn(count, 'estimatedDocumentCount');
+
+			User
+				.estimatedDocumentCount()
+				.exec((err, result) => {
+					expect(result).toBe(count);
+					done();
+				});
+		});
+
 		it('should update with exec and callback', (done) => {
 			mockingoose.User.toReturn({ ok: 1, nModified: 1, n: 1 }, 'update');