Hamcrest - Comment affirmer que vérifier la valeur nulle?
Essayez de vérifier la valeur nulle avec l'assertionHamcrestassertThat, mais vous ne savez pas comment?
@Test
public void testApp()
{
//ambiguous method call?
assertThat(null, is(null));
}
1. Solution
1.1 To check null value, try is(nullValue), remember static import org.hamcrest.CoreMatchers.*
//hello static import, nullValue here
import static org.hamcrest.CoreMatchers.*;
import org.junit.Test;
//...
@Test
public void testApp()
{
//true, check null
assertThat(null, is(nullValue()));
//true, check not null
assertThat("a", is(notNullValue()));
}
1.2 Or this equivalent
import static org.hamcrest.CoreMatchers.*;
import org.hamcrest.core.IsNull;
import org.junit.Test;
//...
@Test
public void testApp()
{
//true, check null
assertThat(null, is(IsNull.nullValue()));
//true, check not null
assertThat("a", is(IsNull.notNullValue()));
}
LeCoreMatchers.nullValue() ci-dessus (1.1), est un raccourci pourIsNull.nullValue, consultez le code source suivant:
org.hamcrest.CoreMatchers.java
public static org.hamcrest.MatchernullValue() { return org.hamcrest.core.IsNull.nullValue(); }
P.S Same to `notNullValue()`
Note
Si vous préférez l'assertion JUnit, essayezassertNull(null)