Assertion Testing is a Boolean expression at a specific point in a program which is considered as true unless there is a bug in the program. A test assertion is explained as an expression, which encapsulates some testable logic specified about a target under test.
How assertions block in testing?
If an assertion is failing due to one or the other reason, the consequence of the same which can be severe. An assertion cloud elevate to a stumbling block which might result in stopping testing for whole day.
The main benefits of assertions are identifying defects in a program. The uses of assertions are listed below
- It is used to detect errors which might get unnoticed
- It may be used for detecting errors quicker after they occur.
- Make statement about the effects of the code that is guaranteed to be true.
What is JUnit Asserts?
Assert is known as a method which is useful in evaluating pass/fail status of a test case, the assert methods are provided by the class org.junit.Assert which extends java.lang.object class.
The Assert methods that are provided by the class org.junit.Assert which extends java.lang.object class.
JUnit Assert methods
- Boolean
If we want to test the Boolean conditions you can use following assert methods.
- AssertTrue(condition)
- assertFalse(condition)
Here the condition is a Boolean value.
- Null object
If you want to check the initial value of any object/variable we have below methods
- assertNull(object)
- assertNotNull(object)
Object is java object e.g assertNull(actual)
- Identical
If we want to check whether objects are identical and also comparing two references to the same java object and may be different.
- AssertSame (expeted, actual), it will return true if expected == actual.
- assertNotSame(expected,actual)
- Assert Equals
If we want to test equality of two objects we have following methods
- assertEquals(expected,actual)
It always returns true if expected. equals (actual) returns true.
- Assert Array Equals
If you want to test equality of arrays we have following methods
- arrayArrayEquals(expected,actual)
here above method must be used if arrays have the same length for each valid value for ‘i’ we can check it is given
- assertEquals(expected[i],actual[i])
- assertArrayEquals(expected[i],actual[i])
- Fail Message
If we want to throw any assertion error, we have to use fail() that always results in a verdict.
- Fail(message);
We will have an assertion testing method with additional String parameter a the first parameter. This string will be appended in failure message if an assertion fails e.g fail(message) can also be written as
asserEquals(message, expected,actual)
JUnit Assert Example
Let us create a simple test class name JUnit4AssertionTest.java and also test runner class TestRunner.java
In this example we will execute our test class using TestRunner.java
Step 1: Consider creating a class covering all important assert statement methods of Junit
package JKUnit.junit;
import static org.junit.Assert.*;
import org.junit.Test;
public class JunitAssertionTest {
@Test
public void testAssert(){
//Variable declaration
String string1="Junit";
String string2="Junit";
String string3="test";
String string4="test";
String string5=null;
int variable1=1;
int variable2=2;
int[] airthematicArrary1 = { 1, 2, 3 };
int[] airthematicArrary2 = { 1, 2, 3 };
//Assert statements
assertEquals(string1,string2);
assertSame(string3, string4);
assertNotSame(string1, string3);
assertNotNull(string1);
assertNull(string5);
assertTrue(variable1<variable2);
assertArrayEquals(airthematicArrary1, airthematicArrary2);
}
}
Step 2: create a TestRunner.java class to execute the above code
package JKUnit.junit;
import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;
public class TestRunner {
public static void main(String[] args) {
Result result = JUnitCore.runClasses(JunitAssertionTest.class);
for (Failure failure : result.getFailures()) {
System.out.println(failure.toString());
}
System.out.println("Result=="+result.wasSuccessful());
}consider all assert statements test one by one see that if they returns true.
step 4: Right click on JunitAssertion.java and click runAs->Junit the output is obtained.
10 Responses
Assertion testing is Boolean Expression that is used to find the errors that go unnoticed otherwise. It also helps in detecting the errors sooner after occurring. The main benefits of assertions are identifying defects in a program that could get unnoticed and it detect errors quicker when they occur. The main issue with this technique is that If an assertion is failing due to one or the other reason, it might result in stopping testing for long period of time. Assert is known as a method which is useful in evaluating pass/fail status of a test case, the assert methods are provided by the class org.junit.Assert which extends java.lang.object class.
Assertion Testing
Assertion Testing is a Boolean expression at a specific point in a program that is considered as true unless there is a bug in the program. A test assertion is explained as an expression, which encapsulates some testable logic specified about a target under test. The main benefits of assertions are identifying defects in a program.
JUnit Asserts
Assert is known as a method which is useful in evaluating pass/fail status of a test case, the assert methods are provided by the class org.junit.Assert which extends java.lang.object class.
JUnit Assert methods
Boolean: If we want to test the Boolean conditions you can use assert methods.
Null object: If you want to check the initial value of any object/variable we can use assert methods
Identical: If we want to check whether objects are identical and also compare two references to the same java object and may be different.
Assert Equals: If we want to test the equality of two objects we can use assert methods
Assert Array Equals: If you want to test the equality of arrays we can use assert methods
Fail Message: If we want to throw an assertion error, we have to use fail() that always results in a verdict.
An assertion is a Boolean expression. It is used to test a logical expression. An assertion is true if the logical expression that is being tested is true and there is no bug in program.
The main benefits of assertions are identifying defects in a program
Assertion Testing is a Boolean expression at a specific point in a program which is considered as true unless there is a bug in the program. A test assertion is explained as an expression, which encapsulates some testable logic specified about a target under test.
Assertion testing is a boolean expression at some specific point in the programwhich is considered as true untill there is some bug found before delivery of project, it helps to find the bugs to meet the customers expectation.
Assertion testing is a Boolean expression or logical expression. Here the program testing result would be true only when Boolean expression tested is true and the program is bug-free. This form of testing can be beneficial to detect errors that go unnoticed and also helps in early detection of errors as and when they occur
Assertion testing is Boolean Expression that is used to find the errors that go unnoticed otherwise. It also helps in detecting the errors sooner after occurring. The main benefits of assertions are identifying defects in a program that could get unnoticed and it detect errors quicker when they occur. The main issue with this technique is that If an assertion is failing due to one or the other reason, it might result in stopping testing for long period of time. Assert is known as a method which is useful in evaluating pass/fail status of a test case, the assert methods are provided by the class org.junit.Assert which extends java.lang.object class.
Assertion testing is testing till you find a defect. Assertion is a method and has a boolean value and returns true till the system encounters an error.
Assertion Testing is a Boolean expression at a specific point in a program which is considered as true unless there is a bug in the program. A test assertion is explained as an expression, which encapsulates some testable logic specified about a target under test. The main benefits of assertions are identifying defects in a program. The uses of assertions are to detect errors which might get unnoticed, being used for detecting errors quicker after they occur, and making statements about the effects of the code that is guaranteed to be true.
Assertion Testing is a Boolean expression at a specific point in a program which is considered as true unless there is a bug in the program. A test assertion is explained as an expression, which encapsulates some testable logic specified about a target under test.
Benefits of assertions testing:
1. It is used to detect subtle errors which might go unnoticed.
2. It is used to detect the error sooner after they occur.