Spectaculous

Spectaculous is a framework that helps you defining specifications with the help of a fluent interface. The idea behind is to put some functional interfaces introduced in Java 8 together to provide a beautiful way to define specifications in pure Java code. Its main use is for testing but you can use for any purpose that requires writing a specification.

How To Build

Just make sure you have Maven and run the command maven package. To install spectaculous on your local maven repository, use the command maven install. Spectaculous is also in Maven Central. Just use the following groupId and artifactId to declare the dependency:

• groupId: io.backpackcloud
• artifactId: spectaculous

Defining Specifications

To define a new specification, use the Spec class. It defines an entry point to the fluent interface:

Account myAccount = new Account(500);

Spec.describe("Money transfer")
  .given(new Account(500))
  .expect(500).from(Account::balance)
  
  .then(account -> account.transfer(100).to(myAccount))

  .expect(400).from(Account::balance)
  
  .because("Accounts should have enough funds to make a transfer")
  .expect(InsufficientBalanceException.class).when(account -> account.transfer(1000).to(myAccount))

Spec.describe("A trader is alerted of status")
  .given(newStock("STK").withThresholdOf(15.0))

  .then(tradeAt(5.0))
  
  .expect("OFF").from(alert())

  .then(tradeAt(16.0))
  .expect("ON").from(alert());

Spec.describe(Address.class)
    .given(Address.fromString("bar"))
    .because("The default channel should be assigned if not provided")
    .expect("default").from(Address::channel)
    .expect("bar").from(Address::id)

    .given(Address.fromString("foo:bar"))
    .because("The pattern channel:id should be used to parse the address")
    .expect("foo").from(Address::channel)
    .expect("bar").from(Address::id)

    .because("Addresses from string should have at least an ID")
    .expect(UnbelievableException.class).when(() -> Address.fromString(""))
    .expect(UnbelievableException.class).when(() -> Address.fromString(null));