The assertion and abnormal processing of the junit interface framework

Junit is an open source test frame for Java programming language for writing unit testing.When using Junit for unit testing, assertion and abnormal treatment are very important. Consecration is a mechanism for judging the test results. It determines whether the test is passed by comparing the actual results and expectations.Junit provides a wealth of assertions that can be used to compare data of various data types.Here are some commonly used assertions: -ASSERTEQULS (Object Expected, Object Actual): Eclabers whether the actual results and expectations are equal. -ASSERTTRUE (BOOLEAN CONDITION): Is the assertion that the condition is true. -ASSERTFALSE (BOOLEAN CONDITION): Is the assertion whether the condition is fake? -ASSERTNULL (Object Object): The assertion is empty. -ASSERTNOTNULL (Object Object): The assertive object is not empty. By using an assertion, we can verify the running results of the code to ensure the correctness of the code. In unit testing, we often need to test whether the code can be processed correctly.Junit provides a set of methods for testing abnormalities. For test cases that are expected to throw abnormal abnormalities, we can use @TEST's extens attributes to specify the expected abnormal type.If the code is thrown out of the specified type of exception during the execution process, the test will be considered to be passed.If there is no abnormality or other types of abnormalities, the test will fail. In addition to using annotations to verify whether the code is thrown out of the expected exception, Junit also provides some methods to deal with exceptions.Here are some commonly used abnormal treatment methods: -ASSERTTHROWS (CLASS ExpectedType, Executable Executable): Is the specified type of exception throwing the specified type when the execution of Executable. -ASSERTDOESNOThrow (Executable Executable): There is no abnormality when asserting executing Executable. The following is a sample code that uses Junit to assert and abnormal processing: import org.junit.jupiter.api.Test; import static org.junit.jupiter.api.Assertions.*; public class ExampleTest { @Test public void testAdd() { int result = add(2, 3); assertEquals(5, result); } @Test public void testDivideByZero() { assertThrows(ArithmeticException.class, () -> divide(6, 0)); } private int add(int a, int b) { return a + b; } private double divide(int dividend, int divisor) { if (divisor == 0) { throw new ArithmeticException("Divisor cannot be zero"); } return dividend / divisor; } } In the above example, the `Testadd` method tests whether the return value of the` ADD` method is correct, and the `testdividebyzero` method tests whether the` DIVIDE` method can properly handle the situation of zero.If the test passes, the console will output the test results.If the test fails, Junit will provide detailed error information to help us locate the problem. In short, Junit's assertion and abnormal processing mechanism provides us with a simple and powerful tool to ensure the correctness and stability of the code.Through reasonable use of assertions and abnormal processing, we can write high -quality unit test code.