Package org.djutils.test

Class UnitTest

java.lang.Object

org.djutils.test.UnitTest

public final class UnitTest
extends Object

UnitTest has the methods to do a testFail(..) method for a unit test.

Copyright (c) 2024-2025 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See for project information https://djutils.org. The DJUTILS project is distributed under a three-clause BSD-style license, which can be found at https://djutils.org/docs/license.html.

Author:

Alexander Verbraeck, Peter Knoppers, Wouter Schakel

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	UnitTest.Assignment<V>	Functional interface for calls to Try.assign(...).
static interface	UnitTest.Execution	Functional interface for calls to Try.execute(...).

Method Summary

Modifier and Type	Method	Description
static <V> V	testFail(UnitTest.Assignment<V> assignment)	Method for unit tests to test if an expected exception is thrown on an assignment.
static <V, T extends Throwable> V	testFail(UnitTest.Assignment<V> assignment, Class<T> expectedThrowableClass)	Method for unit tests to test if an expected exception is thrown on an assignment.
static <V> V	testFail(UnitTest.Assignment<V> assignment, String message)	Method for unit tests to test if an expected exception is thrown on an assignment.
static <V, T extends Throwable> V	testFail(UnitTest.Assignment<V> assignment, String message, Class<T> expectedThrowableClass)	Method for unit tests to test if an expected exception is thrown on an assignment.
static void	testFail(UnitTest.Execution execution)	Method for unit tests to test if an expected exception is thrown on code execution.
static <T extends Throwable> void	testFail(UnitTest.Execution execution, Class<T> expectedThrowableClass)	Method for unit tests to test if an expected exception is thrown on code execution.
static void	testFail(UnitTest.Execution execution, String message)	Method for unit tests to test if an expected exception is thrown on code execution.
static <T extends Throwable> void	testFail(UnitTest.Execution execution, String message, Class<T> expectedThrowableClass)	Method for unit tests to test if an expected exception is thrown on code execution.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

testFail

public static <V> V testFail(UnitTest.Assignment<V> assignment)

Method for unit tests to test if an expected exception is thrown on an assignment. This method does not provide an explanation, and it is not checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the assignment does not throw any exception. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null));
 
 

or

   UnitTest.testFail(new Try.Assignment<Double>()
   {
       @Override
       public Double assign() throws Throwable
       {
           return methodFailsOnNull(null);
       }
   });
 

Type Parameters:

V - value type, which is the return type of the assignment

Parameters:

assignment - functional interface to assign value

Returns:

assigned value

Throws:

AssertionError - when the assignment fails to throw an exception

testFail

public static <V> V testFail(UnitTest.Assignment<V> assignment,
 String message)

Method for unit tests to test if an expected exception is thrown on an assignment. This method provides an explanation message, but it is not checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the assignment does not throw an exception. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null), "call should have thrown an NPE");
 
 

or

   UnitTest.testFail(new Try.Assignment<Double>()
   {
       @Override
       public Double assign() throws Throwable
       {
           return methodFailsOnNull(null);
       }
   }, "call should have thrown an NPE");
 

Type Parameters:

V - value type, which is the return type of the assignment

Parameters:

assignment - functional interface to assign value

message - message to use in the AssertionError when the assignment succeeds

Returns:

assigned value

Throws:

AssertionError - when the assignment fails to throw an exception

testFail

public static <V,
T extends Throwable> V testFail(UnitTest.Assignment<V> assignment,
 Class<T> expectedThrowableClass)

Method for unit tests to test if an expected exception is thrown on an assignment. This method does not provide an explanation, but it is checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the assignment does not throw an exception, or when it throws a different exception than expectedThrowableClass. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null), NullPointerException.class);
 
 

or

   UnitTest.testFail(new Try.Assignment<Double>()
   {
       @Override
       public Double assign() throws Throwable
       {
           return methodFailsOnNull(null);
       }
   }, NullPointerException.class);
 

Type Parameters:

V - value type, which is the return type of the assignment

T - throwable type, which ensures that we provide a throwable class as the argument

Parameters:

assignment - functional interface to assign value

expectedThrowableClass - the class of the exception we expect the assignment to throw

Returns:

assigned value

Throws:

AssertionError - when the assignment fails to throw an exception or the correct exception

testFail

public static <V,
T extends Throwable> V testFail(UnitTest.Assignment<V> assignment,
 String message,
 Class<T> expectedThrowableClass)

Method for unit tests to test if an expected exception is thrown on an assignment. This method provides an explanation message, and it is checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the assignment does not throw an exception, or when it throws a different exception than expectedThrowableClass. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null), "call should have thrown an NPE", NullPointerException.class);
 
 

or

   UnitTest.testFail(new Try.Assignment<Double>()
   {
       @Override
       public Double assign() throws Throwable
       {
           return methodFailsOnNull(null);
       }
   }, "call should have thrown an NPE", NullPointerException.class);
 

Type Parameters:

V - value type, which is the return type of the assignment

T - throwable type, which ensures that we provide a throwable class as the argument

Parameters:

assignment - functional interface to assign value

message - message to use in the AssertionError when the test fails

expectedThrowableClass - the class of the exception we expect the assignment to throw

Returns:

assigned value

testFail

public static void testFail(UnitTest.Execution execution)

Method for unit tests to test if an expected exception is thrown on code execution. This method does not provide an explanation message, nor is it checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the execution does not throw an exception. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null));
 
 

or

   UnitTest.testFail(new Try.Execution()
   {
       @Override
       public void execute() throws Throwable
       {
           methodFailsOnNull(null);
       }
   });
 

Parameters:

execution - functional interface to execute a method that does not need to return a value

testFail

public static void testFail(UnitTest.Execution execution,
 String message)

Method for unit tests to test if an expected exception is thrown on code execution. This method provides an explanation message, but it is not checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the execution does not throw an exception, or when it throws a different exception than expectedThrowableClass. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null), "call should have thrown an NPE");
 
 

or

   UnitTest.testFail(new Try.Execution()
   {
       @Override
       public void execute() throws Throwable
       {
           methodFailsOnNull(null);
       }
   }, "call should have thrown an NPE");
 

Parameters:

execution - functional interface to execute a method that does not need to return a value

message - message to use in the AssertionError when the test fails

testFail

public static <T extends Throwable> void testFail(UnitTest.Execution execution,
 Class<T> expectedThrowableClass)

Method for unit tests to test if an expected exception is thrown on code execution. This method does not provide an explanation message, but it is checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the execution does not throw an exception, or when it throws a different exception than expectedThrowableClass. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null), NullPointerException.class);
 
 

or

   UnitTest.testFail(new Try.Execution()
   {
       @Override
       public void execute() throws Throwable
       {
           methodFailsOnNull(null);
       }
   }, NullPointerException.class);
 

Type Parameters:

T - throwable type, which ensures that we provide a throwable class as the argument

Parameters:

execution - functional interface to execute a method that does not need to return a value

expectedThrowableClass - the class of the exception we expect the execution to throw

testFail

public static <T extends Throwable> void testFail(UnitTest.Execution execution,
 String message,
 Class<T> expectedThrowableClass)

Method for unit tests to test if an expected exception is thrown on code execution. This method provides an explanation message, and it is checking for a specific type of exception to be thrown. The testFail() method throws an AssertionError when the execution does not throw an exception, or when it throws a different exception than expectedThrowableClass. A way to use the method is, for instance:

 
   UnitTest.testFail(() -> methodFailsOnNull(null), "call should have thrown an NPE", NullPointerException.class);
 
 

or

   UnitTest.testFail(new Try.Execution()
   {
       @Override
       public void execute() throws Throwable
       {
           methodFailsOnNull(null);
       }
   }, "call should have thrown an NPE", NullPointerException.class);
 

Type Parameters:

T - throwable type, which ensures that we provide a throwable class as the argument

Parameters:

execution - functional interface to execute a method that does not need to return a value

message - message to use in the AssertionError when the test fails

expectedThrowableClass - the class of the exception we expect the execution to throw