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Expresso 0.9.0

Expresso is a JavaScript TDD framework written for nodejs. Expresso is extremely fast, and is packed with features such as additional assertion methods, code coverage reporting, CI support, and more.

Features

Installation

To install both expresso and node-jscoverage run the command below, which will first compile node-jscoverage:

$ make install

To install expresso alone without coverage reporting run:

$ make install-expresso

Install via npm:

$ npm install expresso

Examples

To define tests we simply export several functions:

exports['test String#length'] = function(){
    assert.equal(6, 'foobar'.length);
};

Alternatively for large numbers of tests you may want to export your own object containing the tests, however this is essentially the as above:

module.exports = {
    'test String#length': function(beforeExit, assert) {
      assert.equal(6, 'foobar'.length);
    }
};

If you prefer not to use quoted keys:

exports.testsStringLength = function(beforeExit, assert) {
    assert.equal(6, 'foobar'.length);
};

The argument passed to each callback is beforeExit and assert. The context ("this") of each test function is a Test object. You can pass a function to beforeExit to make sure the assertions are run before the tests exit. This is can be used to verify that tests have indeed been run. beforeExit is a shortcut for listening to the exit event on this. The second parameter assert is the assert object localized to that test. It makes sure that assertions in asynchronous callbacks are associated with the correct test.

exports.testAsync = function(beforeExit, assert) {
    var n = 0;
    setTimeout(function() {
        ++n;
        assert.ok(true);
    }, 200);
    setTimeout(function() {
        ++n;
        assert.ok(true);
    }, 200);

    // When the tests are finished, the exit event is emitted.
    this.on('exit', function() {
        assert.equal(2, n, 'Ensure both timeouts are called');
    });

    // Alternatively, you can use the beforeExit shortcut.
    beforeExit(function() {
        assert.equal(2, n, 'Ensure both timeouts are called');
    });
};

Assert Utilities

assert.isNull(val[, msg])

Asserts that the given val is null.

assert.isNull(null);

assert.isNotNull(val[, msg])

Asserts that the given val is not null.

assert.isNotNull(undefined);
assert.isNotNull(false);

assert.isUndefined(val[, msg])

Asserts that the given val is undefined.

assert.isUndefined(undefined);

assert.isDefined(val[, msg])

Asserts that the given val is not undefined.

assert.isDefined(null);
assert.isDefined(false);

assert.match(str, regexp[, msg])

Asserts that the given str matches regexp.

assert.match('foobar', /^foo(bar)?/);
assert.match('foo', /^foo(bar)?/);

assert.length(val, n[, msg])

Assert that the given val has a length of n.

assert.length([1,2,3], 3);
assert.length('foo', 3);

assert.type(obj, type[, msg])

Assert that the given obj is typeof type.

assert.type(3, 'number');

assert.eql(a, b[, msg])

Assert that object b is equal to object a. This is an alias for the core assert.deepEqual() method which does complex comparisons, opposed to assert.equal() which uses ==.

assert.eql('foo', 'foo');
assert.eql([1,2], [1,2]);
assert.eql({ foo: 'bar' }, { foo: 'bar' });

assert.includes(obj, val[, msg])

Assert that obj is within val. This method supports Arrays and Stringss.

assert.includes([1,2,3], 3);
assert.includes('foobar', 'foo');
assert.includes('foobar', 'bar');

assert.response(server, req, res|fn[, msg|fn])

Performs assertions on the given server, which should not call listen(), as this is handled internally by expresso and the server is killed after all responses have completed. This method works with any http.Server instance, so Connect and Express servers will work as well.

The req object may contain:

The res object may be a callback function which receives the response for assertions, or an object which is then used to perform several assertions on the response with the following properties:

When providing res you may then also pass a callback function as the fourth argument for additional assertions.

Below are some examples:

assert.response(server, {
    url: '/', timeout: 500
}, {
    body: 'foobar'
});

assert.response(server, {
    url: '/',
    method: 'GET'
}, {
    body: '{"name":"tj"}',
    status: 200,
    headers: {
        'Content-Type': 'application/json; charset=utf-8',
        'X-Foo': 'bar'
    }
});

assert.response(server, {
    url: '/foo',
    method: 'POST',
    data: 'bar baz'
}, {
    body: '/foo bar baz',
    status: 200
}, 'Test POST');

assert.response(server, {
    url: '/foo',
    method: 'POST',
    data: 'bar baz'
}, {
    body: '/foo bar baz',
    status: 200
}, function(res){
    // All done, do some more tests if needed
});

assert.response(server, {
    url: '/'
}, function(res){
    assert.ok(res.body.indexOf('tj') >= 0, 'Test assert.response() callback');
});

This function will fail when it receives no response or when the timeout (default is 30 seconds) expires.

expresso(1)

To run a single test suite (file) run:

$ expresso test/a.test.js

To run several suites we may simply append another:

$ expresso test/a.test.js test/b.test.js

We can also pass a whitelist of tests to run within all suites:

$ expresso --only "foo()" --only "bar()"

Or several with one call:

$ expresso --only "foo(), bar()"

Globbing is of course possible as well:

$ expresso test/*

When expresso is called without any files, test/* is the default, so the following is equivalent to the command above:

$ expresso

If you wish to unshift a path to require.paths before running tests, you may use the -I or --include flag.

$ expresso --include lib test/*

The previous example is typically what I would recommend, since expresso supports test coverage via node-jscoverage (bundled with expresso), so you will need to expose an instrumented version of you library.

To instrument your library, simply run node-jscoverage, passing the src and dest directories:

$ node-jscoverage lib lib-cov

Now we can run our tests again, using the lib-cov directory that has been instrumented with coverage statements:

$ expresso -I lib-cov test/*

The output will look similar to below, depending on your test coverage of course :)

node coverage

To make this process easier expresso has the -c or --cov which essentially does the same as the two commands above. The following two commands will run the same tests, however one will auto-instrument, and unshift lib-cov, and the other will run tests normally:

$ expresso -I lib test/*
$ expresso -I lib --cov test/*

Currently coverage is bound to the lib directory, however in the future --cov will most likely accept a path.

If you would like code coverage reports suitable for automated parsing, pass the --json [output file] option:

$ expresso -I lib test/*
$ expresso -I lib --cov --json coverage.json test/*

You should then see the json coverage details in the file you specified:

{
    "LOC": 20,
    "SLOC": 7,
    "coverage": "71.43",
    "files": {
        "bar.js": {
            "LOC": 4,
            "SLOC": 2,
            "coverage": "100.00",
            "totalMisses": 0
        },
        "foo.js": {
            "LOC": 16,
            "SLOC": 5,
            "coverage": "60.00",
            "totalMisses": 2
        }
    },
    "totalMisses": 2
}

Async Exports

Sometimes it is useful to postpone running of tests until a callback or event has fired, currently the exports.foo = function() {}; syntax is supported for this:

setTimeout(function() {
    exports['test async exports'] = function(){
        assert.ok('wahoo');
    };
}, 100);

Note that you only have one "shot" at exporting. You have to export all of your test functions in the same loop as the first one. That means you can't progressively add more test functions to the exports object.