Read response output buffer/stream with supertest/superagent on node.js server

Question

I am trying to write a test that checks whether an API route outputs a ZIP file with the correct contents.

I am using mocha and supertest for testing, and I would like t

Answer 1

Expanding on @Beau's answer, the following can be used to get any binary response content as a Buffer which you can examine further in request.end():

function binaryParser(res, callback) {
    res.setEncoding('binary');
    res.data = '';
    res.on('data', function (chunk) {
        res.data += chunk;
    });
    res.on('end', function () {
        callback(null, new Buffer(res.data, 'binary'));
    });
}

// example mocha test
it('my test', function(done) {
    request(app)
        .get('/path/to/image.png')
        .expect(200)
        .expect('Content-Type', 'image.png')
        .buffer()
        .parse(binaryParser)
        .end(function(err, res) {
            if (err) return done(err);

            // binary response data is in res.body as a buffer
            assert.ok(Buffer.isBuffer(res.body));
            console.log("res=", res.body);

            done();
        });
});