Package org.assertj.core.condition

Class MappedCondition<FROM,TO>

java.lang.Object
org.assertj.core.api.Condition<FROM>
org.assertj.core.condition.MappedCondition<FROM,TO>
Type Parameters:
FROM - the type of object this condition accepts.
TO - the type of object the nested condition accepts.
All Implemented Interfaces:
Descriptable<Condition<FROM>>
public class MappedCondition<FROM,TO> extends Condition<FROM>
Container Condition that maps the object under test and then check the resulting mapped value against its nested Condition.

Example: 

 Condition<String> hasLineSeparator = new Condition<>(t -> t.contains(System.lineSeparator()), "has lineSeparator");

 Condition<Optional<String>> optionalWithLineSeparator = MappedCondition.mappedCondition(Optional::get, hasLineSeparator, "optional value has lineSeparator");

 // assertion succeeds
 assertThat(Optional.of("a" + System.lineSeparator())).is(optionalWithLineSeparator);
 // returns true
 optionalWithLineSeparator.matches(Optional.of("a" + System.lineSeparator()));

 // assertion fails
 assertThat(Optional.of("a")).is(optionalWithLineSeparator);
 // returns false
 optionalWithLineSeparator.matches(Optional.of("a"));
Author:
Stefan Bischof

  • Method Details

    • mappedCondition

      public static <FROM, TO> MappedCondition<FROM,TO> mappedCondition(Function<FROM,TO> mapping, Condition<TO> condition, String mappingDescription, Object... args)
      Creates a new MappedCondition.

      Example: 

       Condition<String> hasLineSeparator = new Condition<>(t -> t.contains(System.lineSeparator()), "has lineSeparator");

 Condition<Optional<String>> optionalWithLineSeparator = MappedCondition.mappedCondition(Optional::get, hasLineSeparator, "optional value has lineSeparator");

 // assertion succeeds
 assertThat(Optional.of("a" + System.lineSeparator())).is(optionalWithLineSeparator);
 // returns true
 optionalWithLineSeparator.matches(Optional.of("a" + System.lineSeparator()));

 // assertion fails
 assertThat(Optional.of("a")).is(optionalWithLineSeparator);
 // returns false
 optionalWithLineSeparator.matches(Optional.of("a"));

      Note that the mappingDescription argument follows String.format(String, Object...) syntax.

      Type Parameters:
      FROM - the type of object the given condition accept.
      TO - the type of object the nested condition accept.
      Parameters:
      mapping - the Function that maps the value to test to the a value for the nested condition.
      condition - the nested condition to evaluate.
      mappingDescription - describes the mapping, follows String.format(String, Object...) syntax.
      args - for describing the mapping as in String.format(String, Object...) syntax.
      Returns:
      the created MappedCondition.
      Throws:
      NullPointerException - if the given condition is null.
      NullPointerException - if the given mapping is null.

    • mappedCondition

      public static <FROM, TO> MappedCondition<FROM,TO> mappedCondition(Function<FROM,TO> mapping, Condition<TO> condition)
      Creates a new MappedCondition
      Type Parameters:
      FROM - the type of object the given condition accept.
      TO - the type of object the nested condition accept.
      Parameters:
      mapping - the Function that maps the value to test to the a value for the nested condition.
      condition - the nested condition to evaluate.
      Returns:
      the created MappedCondition.
      Throws:
      NullPointerException - if the given condition is null.
      NullPointerException - if the given mapping is null.

    • matches

      public boolean matches(FROM value)
      Maps the value with the given function and verifies that it satisfies the nested Condition.
      Overrides:
      matches in class Condition<FROM>
      Parameters:
      value - the value to map
      Returns:
      true if the given mapped value satisfies the nested condition; false otherwise.

    • buildMappingDescription

      protected String buildMappingDescription(FROM from, TO to)
      Build the mapped condition description when applied with the FROM and TO values.
      Parameters:
      from - the value to map
      to - the mapped value
      Returns:
      the mapped condition description .

    • conditionDescriptionWithStatus

      public Description conditionDescriptionWithStatus(FROM actual)
      Description copied from class: Condition
      Returns the description of this condition with its status failed or success.
      Overrides:
      conditionDescriptionWithStatus in class Condition<FROM>
      Parameters:
      actual - the instance to evaluate the condition status against.
      Returns:
      the description of this condition with its status.