Barriertest NPM

Barrier

A test framework that embraces promises for real

Installation

npm install barriertest

Basic Testing

This part describes the regular sync tests.

Barrier uses RSpec-like syntax to describe tests, and it bundles Chai as the assertion framework, as so:

// Javascript

describe("MyObject", function() {
  it("sums two numbers", function() {
    expect(sum(2, 3)).to.eq(5);
  });
});

# Coffeescript

describe "MyObject", ->
  it "sums two numbers", ->
    expect(sum(2, 3)).to.eq(5)

You can nest describe blocks as you like:

// Javascript

describe("MyObject", function() {
  describe("some internal", function() {
    it("do something", function() {
      expect(something()).to.eq(true);
    });
  });
});

# Coffeescript

describe "MyObject", ->
  describe "some internal", ->
    it "do something", ->
      expect(something()).to.eq(true)

We support before, beforeEach, after and afterEach clauses:

// Javascript

describe("MyObject", function() {
  var someVar = null;

  before(function() { someVar = "hello"; });

  it("must set someVar", function() {
    expect(someVar).to.eq("hello");
  });
});

# Coffeescript

describe "MyObject", ->
  someVar = null

  before -> someVar = "hello"

  it "must set someVar", ->
    expect(someVar).to.eq("hello")

Also, we support lazy blocks for dependency injection:

// Javascript

describe("MyObject", function() {
  lazy("value", function() { return 50; });

  it("loads the value", function(value) {
    expect(value).to.eq(50);
  });
});

# Coffeescript

describe "MyObject", ->
  lazy "value", -> 50

  it "loads the value", (value) ->
    expect(value).to.eq(50)

Note that the we do a reflection on the function to extract the variable name, them we lookup and build it for each test.

And you can inject dependencies on each other:

// Javascript

describe("MyObject", function() {
  lazy("value", function() { return 50; });
  lazy("value2", function(value) { return value + 10; });

  it("loads the values", function(value2) {
    expect(value2).to.eq(60);
  });
});

# Coffeescript

describe "MyObject", ->
  lazy "value", -> 50
  lazy "value2", (value) -> value + 10

  it "loads the values", (value2) ->
    expect(value2).to.eq(60)

Async Testing

For basic async testing, you can call async into the current object to make the test wait:

// Javascript

describe("Awesome", function() {
  return it("supports async testing", function() {
    var done = this.async();

    setTimeout(function() {
      expect(true).to.be["true"]();
      done();
    }, 50);
  });
});

# Coffeescript

describe "Awesome", ->
  it "supports async testing", ->
    done = @async()

    setTimeout ->
      expect(true).to.be.true()
      done()
    , 50

Despites the support on simple async testing, we really recommend you to use promises instead, as described on the next section.

Promises Testing

We recognize that there is a lot of async code into Node, and also, we recognize that promises have a great value in helping to write better async code.

That's why Barrier supports and recommends promises usage over the entire testing process.

But actually there is not much to say about the usage, because it's just transparent! You can just use promises as values and we handle the rest!

Check some examples:

// Javascript

describe("Using Promises", function() {
  it("can use promises as values on expectations", function() {
    expect(loadUser(30)).to.haveProperty("age", fetchRemoteAge());
  });
});

# Coffeescript

describe "Using Promises", ->
  it "can use promises as values on expectations", ->
    # imagine that loadUser and fetchRemoteAge are functions that returns
    # promises that will eventually handle de values
    expect(loadUser(30)).to.haveProperty("age", fetchRemoteAge())

Also, if your test returns a promise, the runner will wait for it:

// Javascript

describe("Delaying the runner", function() {
  it("will wait for my promise", function() {
    return Q("value").delay(30).then(function(v) {
      expect(v).to.eq("value");
    });
  });
});

# Coffeescript

describe "Delaying the runner", ->
  it "will wait for my promise", ->
    Q("value").delay(30).then (v) ->
      expect(v).to.eq("value") # and that's it, Barrier will do the async handling magic

Before and after blocks does the same, if you return promises on they, the runner will wait before going on:

// Javascript

describe("Before promise me...", function() {
  var user, userDecorated;

  before(function() {
    // it's important that you return the promise here so Barrier will know
    // that it needs to wait for it. In Coffeescript it's more transparent
    // since Coffeescript always return the last statement
    return loadUser().then(function(u) {
      user = u;
    });
  });
  // note that before blocks run in series, so, it's safe to expect that previous
  // before blocks are done
  before(function() { userDecorated = decorateUser(user); });

  it("is awesome", function() {
    expect(userDecorated).to.not.be["null"];
  });
});

# Coffeescript

describe "Before promise me...", ->
  user = null
  userDecorated = null

  before -> loadUser().then (u) -> user = u
  # note that before blocks run in series, so, it's safe to expect that previous
  # before blocks are done
  before -> userDecorated = decorateUser(user)

  it "is awesome", -> expect(userDecorated).to.not.be.null

But remember about Lazy Attributes? They can be promises too!

// Javascript

describe("Lazy Promises", function() {
  lazy("user", function() { return findUserOnDB(); });

  it("will load the promise and inject it!", function(user) {
    expect(user.name).to.eq("sir");
  });
});

# Coffeescript

describe "Lazy Promises", ->
  lazy "user", -> findUserOnDB()

  it "will load the promise and inject it!", (user) ->
    expect(user.name).to.eq("sir")

And even better, you can do it while injecting lazy dependencies!

// Javascript

describe("Lazy Promises Dependencies!", function() {
  lazy("store", function() { return createStoreOnDb(); });
  lazy("user", function(store) {
    return createUser({store: store.id});
  });

  it("will load gracefully", function(user) {
    expect(user.store).not.null;
  });
});

# Coffeescript

describe "Lazy Promises Dependencies!", ->
  lazy "store", -> createStoreOnDb()
  lazy "user", (store) -> createUser(store: store.id)

  it "will load gracefully", (user) ->
    expect(user.store).not.null

Get much more examples here