Execution

Parallel by default

specs2 examples are executed concurrently by default:

• this makes the execution faster

• it encourages to write independent examples when the result of a given example should not be influenced by others

Starting from this default you can progressively add constraints to get more control over the execution.

Steps

A Step is an action which can be executed anywhere in a specification. When you declare a Step like this:

class StepSpec extends Specification { def is = s2"""
  this is example 1 $ok
  this is example 2 $ok
  ${step("stop here for a second")}

  this is example 3 $ok
  this is example 4 $ok
"""
}

Then the specification will:

1. execute examples 1 and 2 in parallel
2. execute the step
3. execute examples 3 and 4 in parallel

There is no “result” for a step but if it throws an Exception an Error will be reported. This will not however stop the execution of the rest of the specification.

Stop the execution

You can still control if the rest of the specification must be executed by adding some constraints on the step. For example:

class StepWithStopOnErrorSpec extends Specification { def is = s2"""
  this is example 1 $ok
  this is example 2 $ok
  ${step { sys.error("sorry!"); "stop here for a second" }.stopOnError}

  this is example 3 $ok
  this is example 4 $ok
"""
}

When this specification is executed examples 3 and 4 will be skipped because the step returns an Error. An Error is likely to be a fatal condition but you can use other methods to stop the execution:

• stopOnFail stop if there is a failure in the previous examples or in the step
• stopOnSkipped stop if there is a skipped result in the previous examples or in the step
• stopWhen(Result => Boolean) stop if the and-ed result of the previous examples and the step verifies a given condition

Sequential

If your specification is a list of well-ordered examples you can use the sequential argument to make sure that they are executed in order:

class SequentialSpec extends Specification { def is = sequential ^ s2"""
  this is example 1 $ok
  this is example 2 $ok
  this is example 3 $ok
  this is example 4 $ok
"""
}

Thanks to the sequential argument the 4 examples above will execute one after the other.

Action

Finally if you want to execute “silent” actions, like steps, but with no impact on the sequencing of the specification, you can use an Action:

class ActionSpec extends Specification { def is = s2"""
  this is example 1 $ok
  this is example 2 $ok

  // this will only be reported if there is a failure
  ${action("do something here")}

  this is example 3 $ok
  this is example 4 $ok
"""
}

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