classical BDD interface compatibility support

[cades]

Given/When/Then doesn't cover the functionality that after covers.

For example,

• shut down an HTTP server after each test case.
• reset testdouble

[cades]

Note: there is a same issue in rspec-given.

[cades]

proposal 1: BDD interface

• before / beforeEach / after / afterEach

if a setup needs to tear down, put it in before instead of Given.

proposal 2: new clause

• Cleanup, Afterwards, Ensure or Finally

proposal 3: tell Given to clean up

// change this
Given server: -> Server.listen()

// to this
Given server:
  setup: -> App.listen()
  teardown: -> @server.close()

• rule 1: teardowns are executed in reverse order compared to setups.
• rule 2: if a setup is executed, the corresponding teardown is guaranteed to be executed no matter this test success or fail.
• rule 3: if a setup is not executed, the corresponding teardown will not be executed.

Question

what if after / Cleanup / teardown throws? should it fail the test or be silent ignored?

[cades]

Cleanup clause is implemented in this commit.

Now Given covered beforeEach, Cleanup covered afterEach. But still lack of support to before and after.

Some thoughts:

1. If the underlying test framework provides before / after hook, it will be much simpler for respec-given to implement this feature

2. respec-given has no concept of test suite, so if we want to implement it natively, we need to answer these questions:

   1. how many test belongs to this suite?
   2. does this test is the first/last test of this suite? (if so, execute before / after)

3. need to clearly defined execution order

   Then clause

   1. nearby befores if is the first test in suite
   2. all beforeEachs
   3. all Givens
   4. all Whens
   5. all Invariants
   6. Then
   7. nearby Ands
   8. all Cleanups
   9. all afterEachs
   10. nearby afters if is the last test in suite

   it block

   1. nearby befores if is the first test in suite
   2. all beforeEachs
   3. it
   4. all afterEachs
   5. nearby afters if is the last test in suite