Package org.assertj.core.api

Class IterableAssert<ELEMENT>

    • Constructor Detail

      • IterableAssert

        public IterableAssert​(Iterable<? extends ELEMENT> actual)

    • Method Detail

      • containsOnlyOnce

        @SafeVarargs
public final IterableAssert<ELEMENT> containsOnlyOnce​(ELEMENT... values)
        Description copied from class: AbstractIterableAssert
        Verifies that the actual group contains the given values only once.

        Examples : 

         // lists are used in the examples but it would also work with arrays

 // assertions will pass
 assertThat(newArrayList("winter", "is", "coming")).containsOnlyOnce("winter");
 assertThat(newArrayList("winter", "is", "coming")).containsOnlyOnce("coming", "winter");

 // assertions will fail
 assertThat(newArrayList("winter", "is", "coming")).containsOnlyOnce("Lannister");
 assertThat(newArrayList("Arya", "Stark", "daughter", "of", "Ned", "Stark")).containsOnlyOnce("Stark");
 assertThat(newArrayList("Arya", "Stark", "daughter", "of", "Ned", "Stark")).containsOnlyOnce("Stark", "Lannister", "Arya");
        Specified by:
        containsOnlyOnce in interface ObjectEnumerableAssert<IterableAssert<ELEMENT>,​ELEMENT>
        Overrides:
        containsOnlyOnce in class AbstractIterableAssert<IterableAssert<ELEMENT>,​Iterable<? extends ELEMENT>,​ELEMENT,​ObjectAssert<ELEMENT>>
        Parameters:
        values - the given values.
        Returns:
        this assertion object.

      • flatExtracting

        @SafeVarargs
public final <EXCEPTION extends Exception> AbstractListAssert<?,​List<?>,​Object,​ObjectAssert<Object>> flatExtracting​(ThrowingExtractor<? super ELEMENT,​?,​EXCEPTION>... extractors)
        Description copied from class: AbstractIterableAssert
        Extracts multiple values from each Iterable's element according to the given ThrowingExtractors and concatenates/flattens them in a list that becomes the object under test.

        If extracted values were not flattened, instead of a simple list like (given 2 extractors): 

          element1.value1, element1.value2, element2.value1, element2.value2, ...
        we would get a list of list like: 
          list(element1.value1, element1.value2), list(element2.value1, element2.value2), ...

        Example: 

         // fellowshipOfTheRing is a List<TolkienCharacter>

 // values are extracted in order and flattened: age1, name1, age2, name2, age3 ...
 assertThat(fellowshipOfTheRing).flatExtracting(input -> {
   if (input.getAge() < 20) {
     throw new Exception("age < 20");
   }
   return input.getName();
 }, input2 -> {
   if (input2.getAge() < 20) {
     throw new Exception("age < 20");
   }
   return input2.getAge();
 }).contains(33 ,"Frodo",
     1000, "Legolas",
     87, "Aragorn");
        The resulting extracted values list is ordered by Iterable's element first and then extracted values, this is why is in the example age values come before names.
        Overrides:
        flatExtracting in class AbstractIterableAssert<IterableAssert<ELEMENT>,​Iterable<? extends ELEMENT>,​ELEMENT,​ObjectAssert<ELEMENT>>
        Type Parameters:
        EXCEPTION - the exception type of ThrowingExtractor
        Parameters:
        extractors - all the extractors to apply on each actual Iterable's elements
        Returns:
        a new assertion object whose object under test is a flattened list of all extracted values.

      • flatMap

        @SafeVarargs
public final <EXCEPTION extends Exception> AbstractListAssert<?,​List<? extends Object>,​Object,​ObjectAssert<Object>> flatMap​(ThrowingExtractor<? super ELEMENT,​?,​EXCEPTION>... mappers)
        Description copied from class: AbstractIterableAssert
        Maps multiple values from each Iterable's element according to the given ThrowingExtractors and concatenates/flattens them in a list that becomes the object under test.

        If mapped values were not flattened, instead of a simple list like (given 2 mappers): 

          element1.value1, element1.value2, element2.value1, element2.value2, ...
        we would get a list of list like: 
          list(element1.value1, element1.value2), list(element2.value1, element2.value2), ...

        Example: 

         // fellowshipOfTheRing is a List<TolkienCharacter>

 // values are extracted in order and flattened: age1, name1, age2, name2, age3 ...
 assertThat(fellowshipOfTheRing).flatMap(input -> {
   if (input.getAge() < 20) {
     throw new Exception("age < 20");
   }
   return input.getName();
 }, input2 -> {
   if (input2.getAge() < 20) {
     throw new Exception("age < 20");
   }
   return input2.getAge();
 }).contains(33 ,"Frodo",
     1000, "Legolas",
     87, "Aragorn");
        The resulting mapped values list is ordered by Iterable's element first and then mapped values, this is why is in the example age values come before names.
        Overrides:
        flatMap in class AbstractIterableAssert<IterableAssert<ELEMENT>,​Iterable<? extends ELEMENT>,​ELEMENT,​ObjectAssert<ELEMENT>>
        Type Parameters:
        EXCEPTION - the exception type of ThrowingExtractor
        Parameters:
        mappers - all the mappers to apply on each actual Iterable's elements
        Returns:
        a new assertion object whose object under test is a flattened list of all extracted values.

      • flatExtracting

        @SafeVarargs
public final AbstractListAssert<?,​List<?>,​Object,​ObjectAssert<Object>> flatExtracting​(Function<? super ELEMENT,​?>... extractors)
        Description copied from class: AbstractIterableAssert
        Extracts multiple values from each Iterable's element according to the given Functions and concatenates/flattens them in a list that becomes the instance under test.

        If extracted values were not flattened, instead of a simple list like (given 2 extractors): 

          element1.value1, element1.value2, element2.value1, element2.value2, ...
        we would get a list of list like: 
          list(element1.value1, element1.value2), list(element2.value1, element2.value2), ...

        Example: 

         // fellowshipOfTheRing is a List<TolkienCharacter>

 // values are extracted in order and flattened: age1, name1, age2, name2, age3 ...
 assertThat(fellowshipOfTheRing).flatExtracting(TolkienCharacter::getAge,
                                                TolkienCharacter::getName)
                                .contains(33 ,"Frodo",
                                          1000, "Legolas",
                                          87, "Aragorn");
        The resulting extracted values list is ordered by Iterable's element first and then extracted values, this is why is in the example age values come before names.
        Overrides:
        flatExtracting in class AbstractIterableAssert<IterableAssert<ELEMENT>,​Iterable<? extends ELEMENT>,​ELEMENT,​ObjectAssert<ELEMENT>>
        Parameters:
        extractors - all the extractors to apply on each actual Iterable's elements
        Returns:
        a new assertion object whose object under test is a flattened list of all extracted values.

      • flatMap

        @SafeVarargs
public final AbstractListAssert<?,​List<? extends Object>,​Object,​ObjectAssert<Object>> flatMap​(Function<? super ELEMENT,​?>... mappers)
        Description copied from class: AbstractIterableAssert
        Maps multiple values from each Iterable's element according to the given Functions and concatenates/flattens them in a list that becomes the instance under test.

        If mapped values were not flattened, instead of a simple list like (given 2 extractors): 

          element1.value1, element1.value2, element2.value1, element2.value2, ...
        we would get a list of list like: 
          list(element1.value1, element1.value2), list(element2.value1, element2.value2), ...

        Example: 

         // fellowshipOfTheRing is a List<TolkienCharacter>

 // values are extracted in order and flattened: age1, name1, age2, name2, age3 ...
 assertThat(fellowshipOfTheRing).flatMap(TolkienCharacter::getAge,
                                         TolkienCharacter::getName)
                                .contains(33 ,"Frodo",
                                          1000, "Legolas",
                                          87, "Aragorn");
        The resulting mapped values list is ordered by Iterable's element first and then mapped values, this is why is in the example age values come before names.
        Overrides:
        flatMap in class AbstractIterableAssert<IterableAssert<ELEMENT>,​Iterable<? extends ELEMENT>,​ELEMENT,​ObjectAssert<ELEMENT>>
        Parameters:
        mappers - all the mappers to apply on each actual Iterable's elements
        Returns:
        a new assertion object whose object under test is a flattened list of all mapped values.

      • extracting

        @SafeVarargs
public final AbstractListAssert<?,​List<? extends Tuple>,​Tuple,​ObjectAssert<Tuple>> extracting​(Function<? super ELEMENT,​?>... extractors)
        Description copied from class: AbstractIterableAssert
        Use the given Functions to extract the values from the Iterable's elements into a new Iterable composed of Tuples (a simple data structure containing the extracted values), this new Iterable becoming the object under test.

        It allows you to test values from the Iterable's elements instead of testing the elements themselves, which sometimes can be much less work!

        The Tuple data correspond to the extracted values from the Iterable's elements, for instance if you pass functions extracting "id", "name" and "email" values then each Tuple data will be composed of an id, a name and an email extracted from the element of the initial Iterable (the Tuple's data order is the same as the given functions order).

        Let's take a look at an example to make things clearer: 

         // Build a list of TolkienCharacter, a TolkienCharacter has a name, and age and a Race (a specific class)
 // they can be public field or properties, both can be extracted.
 List<TolkienCharacter> fellowshipOfTheRing = new ArrayList<TolkienCharacter>();

 fellowshipOfTheRing.add(new TolkienCharacter("Frodo", 33, HOBBIT));
 fellowshipOfTheRing.add(new TolkienCharacter("Sam", 38, HOBBIT));
 fellowshipOfTheRing.add(new TolkienCharacter("Gandalf", 2020, MAIA));
 fellowshipOfTheRing.add(new TolkienCharacter("Legolas", 1000, ELF));
 fellowshipOfTheRing.add(new TolkienCharacter("Pippin", 28, HOBBIT));
 fellowshipOfTheRing.add(new TolkienCharacter("Gimli", 139, DWARF));
 fellowshipOfTheRing.add(new TolkienCharacter("Aragorn", 87, MAN);
 fellowshipOfTheRing.add(new TolkienCharacter("Boromir", 37, MAN));

 // let's verify 'name', 'age' and Race of some TolkienCharacter in fellowshipOfTheRing:
 assertThat(fellowshipOfTheRing).extracting(TolkienCharacter::getName,
                                            character -> character.getAge(),
                                            TolkienCharacter::getRace)
                                .containsOnly(tuple("Frodo", 33, HOBBIT),
                                              tuple("Sam", 38, HOBBIT),
                                              tuple("Gandalf", 2020, MAIA),
                                              tuple("Legolas", 1000, ELF),
                                              tuple("Pippin", 28, HOBBIT),
                                              tuple("Gimli", 139, DWARF),
                                              tuple("Aragorn", 87, MAN),
                                              tuple("Boromir", 37, MAN));
        You can use lambda expression or a method reference to extract the expected values.

        Use Tuple.tuple(Object...) to initialize the expected values.

        Note that the order of the extracted tuples list is consistent with the iteration order of the Iterable under test, for example if it's a HashSet, you won't be able to make any assumptions on the extracted tuples order.

        Overrides:
        extracting in class AbstractIterableAssert<IterableAssert<ELEMENT>,​Iterable<? extends ELEMENT>,​ELEMENT,​ObjectAssert<ELEMENT>>
        Parameters:
        extractors - the extractor functions to extract a value from an element of the Iterable under test.
        Returns:
        a new assertion object whose object under test is the list of Tuples containing the extracted values.

      • map

        @SafeVarargs
public final AbstractListAssert<?,​List<? extends Tuple>,​Tuple,​ObjectAssert<Tuple>> map​(Function<? super ELEMENT,​?>... mappers)
        Description copied from class: AbstractIterableAssert
        Use the given Functions to map the Iterable's elements into a List of Tuples (a simple data structure containing the mapped values), this new list becoming the object under test.

        This allows you to test values from the Iterable's elements instead of testing the elements themselves, which sometimes can be much less work!

        The Tuple data correspond to the extracted values from the Iterable's elements, for instance if you pass functions mapping "id", "name" and "email" values then each Tuple data will be composed of an id, a name and an email mapped from the element of the initial Iterable (the Tuple's data order is the same as the given functions order).

        Let's take a look at an example to make things clearer: 

         // Build a list of TolkienCharacter, a TolkienCharacter has a name, and age and a Race (a specific class)
 // they can be public field or properties, both can be extracted.
 List<TolkienCharacter> fellowshipOfTheRing = new ArrayList<TolkienCharacter>();

 fellowshipOfTheRing.add(new TolkienCharacter("Frodo", 33, HOBBIT));
 fellowshipOfTheRing.add(new TolkienCharacter("Sam", 38, HOBBIT));
 fellowshipOfTheRing.add(new TolkienCharacter("Gandalf", 2020, MAIA));
 fellowshipOfTheRing.add(new TolkienCharacter("Legolas", 1000, ELF));
 fellowshipOfTheRing.add(new TolkienCharacter("Pippin", 28, HOBBIT));
 fellowshipOfTheRing.add(new TolkienCharacter("Gimli", 139, DWARF));
 fellowshipOfTheRing.add(new TolkienCharacter("Aragorn", 87, MAN);
 fellowshipOfTheRing.add(new TolkienCharacter("Boromir", 37, MAN));

 // let's verify 'name', 'age' and Race of some TolkienCharacter in fellowshipOfTheRing:
 assertThat(fellowshipOfTheRing).map(TolkienCharacter::getName,
                                     character -> character.getAge(),
                                     TolkienCharacter::getRace)
                                .containsOnly(tuple("Frodo", 33, HOBBIT),
                                              tuple("Sam", 38, HOBBIT),
                                              tuple("Gandalf", 2020, MAIA),
                                              tuple("Legolas", 1000, ELF),
                                              tuple("Pippin", 28, HOBBIT),
                                              tuple("Gimli", 139, DWARF),
                                              tuple("Aragorn", 87, MAN),
                                              tuple("Boromir", 37, MAN));
        You can use lambda expression or a method reference to extract the expected values.

        Use Tuple.tuple(Object...) to initialize the expected values.

        Note that the order of the extracted tuples list is consistent with the iteration order of the Iterable under test, for example if it's a HashSet, you won't be able to make any assumptions on the extracted tuples order.

        Overrides:
        map in class AbstractIterableAssert<IterableAssert<ELEMENT>,​Iterable<? extends ELEMENT>,​ELEMENT,​ObjectAssert<ELEMENT>>
        Parameters:
        mappers - the mapper functions to extract a value from an element of the Iterable under test.
        Returns:
        a new assertion object whose object under test is the list of Tuples containing the extracted values.