Cum să utilizați Hamcrest assertThat() Matchers pentru a crea cazuri de testare JUnit în Java - Tutorial complet

Publicat: 2022-02-05
Cum să utilizați Hamcrest assertThat() Matchers pentru a crea cazuri de testare JUnit în Java

Cum se utilizează Hamcrest for testing ? Cu ceva timp în urmă am scris un articol Hello World JUnit cu toate detaliile. În acest tutorial vom trece peste pașii despre how to use Hamcrest to create JUnit pentru proiectul dvs. Java.

Hamcrest este un testing framework pentru Java cu potriviri incluse în cadrul JUnit pentru a crea teste unitare Java mai lizibile. L-am incercat azi si imi place absolut.

Documentația foarte simplă și completă îl face perfect.

Dacă aveți oricare dintre întrebările de mai jos, vă aflați la locul potrivit:

  • Scrierea cazurilor de testare JUnit în Java folosind Eclipse
  • Cum se scrie cazuri de testare junit în Java
  • Exemple de cazuri de testare JUnit în Java
  • Scrierea cazurilor de testare JUnit folosind Hamcrest Matchers
  • Beneficiile assertThat vs Assert în testele JUnit
  • tutorial hamcrest assertthat()
  • Testare cu Hamcrest

Să începem:

Creați clasa Java CrunchifyHemcrestJUnitTest.java în Eclipse. Vom crea 4 categorii diferite de teste.

  1. Creați cazuri de testare JUnit pentru Java List
  2. Creați cazuri de testare JUnit pentru Java Map
  3. Creați cazuri de testare JUnit pentru obiectul Java
  4. Creați cazuri de testare JUnit pentru Null Check

Iată cei mai buni jucători Hamcrest:

  • este()
  • areItems()
  • hasSize()
  • conține()
  • containsInAnyOrder()

Tutorialul de mai jos acoperă aproape toate cazurile de testare pentru potriviri, care vor trece tot timpul. Doar modificați pentru a crea fals pozitiv și așa mai departe.

Trebuie să adăugați mai jos dependența Maven în proiectul dvs.

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< dependency >
< groupId > org . hamcrest < / groupId >
< artifactId > hamcrest - all < / artifactId >
< version > 1.3 < / version >
< / dependency >

Doar adăugați acest lucru în fișierul pom.xml . Dacă nu vedeți pom.xml, urmați acest tutorial.

conţine în orice ordine-hamcrest-java-junit-test

Iată un cod Java complet

Doar faceți clic dreapta pe o clasă și Run As -> JUnit Test .

CrunchifyHamcrestJUnitTest.java

Java
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package crunchify . com . java . tutorials ;
 
import org . hamcrest . collection . IsEmptyCollection ;
import org . hamcrest . collection . IsMapContaining ;
import org . hamcrest . core . IsNull ;
import org . junit . Test ;
 
import java . util . * ;
 
import static org . hamcrest . CoreMatchers . * ;
import static org . hamcrest . MatcherAssert . assertThat ;
import static org . hamcrest . Matchers . hasProperty ;
import static org . hamcrest . collection . IsCollectionWithSize . hasSize ;
import static org . hamcrest . collection . IsIterableContainingInAnyOrder . containsInAnyOrder ;
import static org . hamcrest . collection . IsIterableContainingInOrder . contains ;
 
/**
* @author Crunchify.com
* <p>
* Hamcrest JUnit Tutorials by Crunchify.com
* 1. Create JUnit testcases for Java List
* 2. Create JUnit testcases for Java Map
* 3. Create JUnit testcases for Java Object
* 4. Create JUnit testcases for Null Check
*/
 
public class CrunchifyHamcrestJUnitTest {
// Testcase-1: JUnit for List
@Test
public void crunchifyListJUnitTests ( ) {
// List: An ordered collection (also known as a sequence). The user of this interface has precise control over where in the list each element is inserted.
// The user can access elements by their integer index (position in the list), and search for elements in the list.
List <String> company = Arrays . asList ( "Crunchify.com" , "Google.com" , "Facebook.com" ) ;
// asList(): Returns a fixed-size list backed by the specified array. Changes made to the array will be visible in the returned list,
// and changes made to the list will be visible in the array.
// The returned list is Serializable and implements RandomAccess.
List <String> crunchifyCompany = Arrays . asList ( "Crunchify.com" , "Google.com" , "Facebook.com" ) ;
crunchifyLog ( "\n~~~~~~~~~~~JUnit List Check Test~~~~~~~~~~~" ) ;
crunchifyLog ( "1) assertThat(company, is(crunchifyCompany)) check" ) ;
// A shortcut to the frequently used is(equalTo(x)).
assertThat ( company , is ( crunchifyCompany ) ) ;
crunchifyLog ( "2) .hasItems() check" ) ;
assertThat ( company , hasItems ( "Crunchify.com" ) ) ;
crunchifyLog ( "3) .hasSize() check" ) ;
assertThat ( company , hasSize ( 3 ) ) ;
assertThat ( company . size ( ) , is ( 3 ) ) ;
crunchifyLog ( "4) .contains() and .containsInAnyOrder() check" ) ;
assertThat ( company , contains ( "Crunchify.com" , "Google.com" , "Facebook.com" ) ) ;
assertThat ( company , containsInAnyOrder ( "Google.com" , "Crunchify.com" , "Facebook.com" ) ) ;
// FAIL
// assertThat(company, contains("Google.com", "Crunchify.com", "Facebook.com"));
crunchifyLog ( "5) .empty() check" ) ;
assertThat ( company , not ( IsEmptyCollection . empty ( ) ) ) ;
assertThat ( new ArrayList < > ( ) , IsEmptyCollection . empty ( ) ) ;
}
private void crunchifyLog ( String crunchifyText ) {
System . out . println ( crunchifyText ) ;
}
@Test
public void crunchifyMapJUnitTests ( ) {
Map < String , String > company = new HashMap < > ( ) ;
company . put ( "C" , "Crunchify.com" ) ;
company . put ( "G" , "Google.com" ) ;
company . put ( "F" , "Facebook.com" ) ;
// Map: An object that maps keys to values. A map cannot contain duplicate keys; each key can map to at most one value.
// This interface takes the place of the Dictionary class, which was a totally abstract class rather than an interface.
Map < String , String > crunchifyCompany = new HashMap < > ( ) ;
crunchifyCompany . put ( "C" , "Crunchify.com" ) ;
// put(): Associates the specified value with the specified key in this map (optional operation).
// If the map previously contained a mapping for the key, the old value is replaced by the specified value.
// (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)
crunchifyCompany . put ( "G" , "Google.com" ) ;
crunchifyCompany . put ( "F" , "Facebook.com" ) ;
crunchifyLog ( "\n~~~~~~~~~~~ JUnit Map Check Test - All tests will PASS in our example ~~~~~~~~~~~" ) ;
crunchifyLog ( "1) assertThat(company, is(crunchifyCompany) check" ) ;
assertThat ( company , is ( crunchifyCompany ) ) ;
crunchifyLog ( "2) assertThat(company.size(), is(3)) check" ) ;
assertThat ( company . size ( ) , is ( 3 ) ) ;
crunchifyLog ( "3) .hasEntry() check which creates a matcher for Maps matching at least one entry whose key equals the specified key & value." ) ;
assertThat ( company , IsMapContaining . hasEntry ( "C" , "Crunchify.com" ) ) ;
assertThat ( company , not ( IsMapContaining . hasEntry ( "G" , "Twitter.com" ) ) ) ;
crunchifyLog ( "4) .hasKey() creates a matcher for Maps matching at least one key that is equal to the specified key." ) ;
assertThat ( company , IsMapContaining . hasKey ( "F" ) ) ;
crunchifyLog ( "5) .hasValue() creates a matcher for Maps matching at least one key that is equal to the specified value." ) ;
assertThat ( company , IsMapContaining . hasValue ( "Crunchify.com" ) ) ;
}
@SuppressWarnings ( "unchecked" )
@Test
public void crunchifyObjectJUnitTests ( ) {
List <Company> list = Arrays . asList ( new Company ( "Crunchify" , 10 ) , new Company ( "Google" , 30000 ) ) ;
assertThat ( list , hasItems ( new Company ( "Crunchify" , 10 ) , new Company ( "Google" , 30000 ) ) ) ;
assertThat ( list , containsInAnyOrder ( new Company ( "Google" , 30000 ) , new Company ( "Crunchify" , 10 ) ) ) ;
assertThat ( list , containsInAnyOrder ( hasProperty ( "name" , is ( "Google" ) ) , hasProperty ( "name" , is ( "Crunchify" ) ) ) ) ;
crunchifyLog ( "\n~~~~~~~~~~~ JUnit Object Check Test Completed ~~~~~~~~~~~" ) ;
}
// Create Company Object
public static class Company {
public Company ( String name , int employeeCount ) {
this . name = name ;
this . employeeCount = employeeCount ;
}
private String name ;
private int employeeCount ;
public int getEmployeeCount ( ) {
return employeeCount ;
}
public void setEmployeeCount ( int employeeCount ) {
this . employeeCount = employeeCount ;
}
public String getName ( ) {
return name ;
}
public void setName ( String name ) {
this . name = name ;
}
// Test equal, override equals() and hashCode()
@Override
public boolean equals ( Object c ) {
if ( this == c )
return true ;
if ( c == null | | getClass ( ) ! = c . getClass ( ) )
return false ;
Company fruit = ( Company ) c ;
return employeeCount == fruit . employeeCount && Objects.equals(name, fruit.name);
}
@Override
public int hashCode ( ) {
return Objects . hash ( name , employeeCount ) ;
}
}
@Test
public void crunchifyNullCheckJUnitTest ( ) {
// Two ways to check isNull
assertThat ( null , is ( nullValue ( ) ) ) ;
assertThat ( null , is ( IsNull . nullValue ( ) ) ) ;
// Two ways to check isNotNull
assertThat ( "crunchify" , is ( notNullValue ( ) ) ) ;
assertThat ( "crunchify" , is ( IsNull . notNullValue ( ) ) ) ;
crunchifyLog ( "\n~~~~~~~~~~~ JUnit Null Check Test Completed ~~~~~~~~~~~" ) ;
}
}

Ieșirea consolei Eclipse:

Doar rulați programul de mai sus ca o aplicație Java și ar trebui să vedeți rezultatul ca mai jos.

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~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ JUnit Object Check Test Completed ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
 
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ JUnit Null Check Test Completed ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
 
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ JUnit List Check Test ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
1 ) assertThat ( company , is ( crunchifyCompany ) ) check
2 ) . hasItems ( ) check
3 ) . hasSize ( ) check
 
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ JUnit List Check Test ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
1 ) assertThat ( company , is ( crunchifyCompany ) ) check
2 ) . hasItems ( ) check
3 ) . hasSize ( ) check
4 ) . contains ( ) and . containsInAnyOrder ( ) check
5 ) . empty ( ) check
 
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ JUnit Map Check Test - All tests will PASS in our example ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
1 ) assertThat ( company , is ( crunchifyCompany ) check
2 ) assertThat ( company . size ( ) , is ( 3 ) ) check
3 ) . hasEntry ( ) check which creates a matcher for Maps matching at least one entry whose key equals the specified key & value .
4 ) . hasKey ( ) creates a matcher for Maps matching at least one key that is equal to the specified key .
5 ) . hasValue ( ) creates a matcher for Maps matching at least one key that is equal to the specified value .
 
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ JUnit Object Check Test Completed ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
 
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ JUnit Null Check Test Completed ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
 
Process finished with exit code 0
hamcrest-java-junit-test-rezultat

Anunțați-ne dacă vă confruntați cu vreo problemă la rularea programului de mai sus.