[FIXED] Mocking InputStream, InputStreamReader and BufferedReader

Issue

I have the following piece of code :

InputStream inputStream = sftpConfig.getSftpChannel().get(fileAbsolutePath);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)))
String line = bufferedReader.readLine();

All I want is to mock these lines, and be flexible in bufferedReader.readLine(), because I will have several test cases depending on the lines (a case where the file is empty and the line is null, a case where I get only one line, a case where I get several etc.).

Note : I am using jsch library for accessing files on FTP servers, so the method getSftpChannel() has ChannelSftp as return type, and get(fileAbsolutePath) has InputStream.

I am using junit 4.12 and mockito 3.1.0

Thanks in advance!

Solution

It's probably easier just to instantiate ByteArrayInputStream instance instead of mocking it and filling it with data you need, e.g.

var stream = new ByteArrayInputStream("hello".getBytes());

and you can just use that in place of your InputStream.

Answered By - Alex
Answer Checked By - Terry (JavaFixing Volunteer)