Is there a Hamcrest "for each" Matcher that asserts all elements of a Collection or Iterable match a single specific Matcher?

Question

Given a Collection or Iterable of items, is there any Matcher (or combination of matchers) that will assert every item matches a single Matcher?

For example, given this item type:

public interface Person {     public String getGender(); } 

I'd like to write an assertion that all items in a collection of Persons have a specific gender value. I'm thinking something like this:

Iterable<Person> people = ...; assertThat(people, each(hasProperty("gender", "Male"))); 

Is there any way to do this without writing the each matcher myself?

Answer 1

Use the Every matcher.

import org.hamcrest.beans.HasPropertyWithValue; import org.hamcrest.core.Every; import org.hamcrest.core.Is; import org.junit.Assert;  Assert.assertThat(people, (Every.everyItem(HasPropertyWithValue.hasProperty("gender", Is.is("male"))))); 

Hamcrest also provides Matchers#everyItem as a shortcut to that Matcher.

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Full example

@org.junit.Test public void method() throws Exception {     Iterable<Person> people = Arrays.asList(new Person(), new Person());     Assert.assertThat(people, (Every.everyItem(HasPropertyWithValue.hasProperty("gender", Is.is("male"))))); }  public static class Person {     String gender = "male";      public String getGender() {         return gender;     }      public void setGender(String gender) {         this.gender = gender;     } }