How to assert that Set has item with exact property with hamcrest

Question

i've been trying assert that my Set has collection with given property with hamcrest, using this solution, but i have :

java.lang.NoSuchMethodError: org.hamcrest.Matcher.describeMismatch(Ljava/lang/Object;Lorg/hamcrest/Description;)V at org.hamcrest.Condition$Matched.matching(Condition.java:52)

imports:

import static org.hamcrest.Matchers.contains;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasProperty;
import static org.junit.Assert.assertThat;

code:

assertThat(mySet, contains(hasProperty("id", equalTo("expectedId"))));

have You any ideas how to assert it well ?

Answer 1

Well, you should try to let assertThat do the work for you.

Set<WhateverPropertyTypeYouAreUsing> expectedSet = Collections.singleton( ... create a property object with that id/value);

assertThat(mySet, is(expectedSet))

The restriction here: that assumes that your set contains only that one property value.

Otherwise, you can go for:

assertThat(mySet.contains(someProperty), is(true))

(probably with an additional message to better describe a failing assert).

Prereq: your property class should be implementing equals() in a reasonable manner.