mock-res

Mocks node.js http.ServerResponse. See also `mock-req`.

Usage no npm install needed!

<script type="module">
  import mockRes from 'https://cdn.skypack.dev/mock-res';
</script>

README

mock-res

Mocks node.js http.ServerResponse (a response). See also mock-req.

Being a readable/writable stream, you can pipe the response body to and from it.

Usage

See test.js for further usage.

var MockRes = require('mock-res');

// Basic usage
var res = new MockRes();

// Supply a callback to be called after res.end() is called
var res = new MockRes(function onEnd() {
    console.log('Response sent');
});

// Listen for stream events
res.on('error', function (err) {
    // If not listened for, the 'error' event will throw,
    // as is true for any stream.
});
res.on('finish', function () {
    console.log('Finished writing response');
});

// Read status code
res.statusCode; // 200 by default

// Read body as string
res._getString(); // 'I am a chicken';

// Read body as parsed JSON
res._getJSON(); // { chicken: true }

// Pipe body somewhere
res.pipe(fs.createWriteStream('/tmp/yo'));

Example test case

var assert = require('assert');
var list = require('./list-handler');
var MockRes = require('mock-res');

function test(done) {
    /* Arrange */

    // Use `mock-req` for a better mock
    var req = {
        method: 'GET',
        url: '/foos'
    }

    var res = new MockRes(onEnd);

    /* Act */
    list(req, res);

    /* Assert */
    function onEnd() {
        // NOTE `this` === `res`

        assert.equal(this.statusCode, 200);
        assert.equal(this._getString(), '[{"id":0},{"id":1}]');
        assert.deepEqual(this._getJSON(), [{id: 0 }, {id: 1 }]);
        assert.deepEqual(this.getHeader('set-cookie'), ['a=1', 'b=2']);

        res.pipe(process.stdout); // `res` is just a readable stream here

        done(); // this is an async test
    }
}

Methods

  • All readable/writable stream methods.
  • writeHead(statusCode, [reasonPhrase], [headers]) Sets the response status code, status message, and headers. See also the http.ServerResponse documentation.
  • setHeader(), getHeader(), getHeaders(), removeHeader()
  • _getString() Reads the body as a string, from the internal stream buffer.
  • _getJSON() Reads the body as a parsed JSON object, from the internal stream buffer.