Conditional Steps

The conditional steps mechanism allows the user to choose a step to execute based on the result of predicate evaluation. This mechanism can be used instead of conditional statements like if-else/switch in case of grow of number of steps with the same naming but different internal logic.

Let's consider the following switch operator with a bunch of conditions:

    @Given("food for my pet")
    public void prepareFoodForMyPet() {
        String partOfDay = ...;
        switch (partOfDay) {
            case "morning":
                // logic for morning
                break;
            case "evening":
                // logic for evening
                break;
            case "afternoon":
                // logic for evening
                break;
        }
    }
    

With conditional steps the logic can be rewritten in the following way:

    @Conditional(condition = PartOfDayCondition.class, value = "morning")
    @Given("food for my pet")
    public void prepareMorningFood() {
        // logic for morning
    }

    @Conditional(condition = PartOfDayCondition.class, value = "evening")
    @Given("food for my pet")
    public void prepareEveningFood() {
        // logic for evening
    }

    @Conditional(condition = PartOfDayCondition.class, value = "afternoon")
    @Given("food for my pet")
    public void prepareAfternoonFood() {
        // logic for afternoon
    }
    

To make this work we need the following condition implementation:

    public class PartOfDayCondition implements Predicate\
    {
        @Override
        public boolean test(Object value)
        {
            String partOfDay = ...;
            return partOfDay.equals(value);
        }
    }
    

By default conditions are checked by DefaultStepConditionMatcher that requires conditions to have public non-args constructor, custom step condition matcher can be created by implementing the StepConditionMatcher interface and then registering the new implementation in a Configuration instance.

Notes:

• a condition at the method level has higher priority than a condition at the class level
• if a step is annotated as conditional, then all the steps with the same wording must be conditional, otherwise, an exception is thrown
• step is marked as pending if there are no steps matched condition or there is more than one matched step