JUnit 4 Unit Test

individual Project

　　　　　　--junit 4 Unit Test

Learning to JUnit unit tests, I tested a calculator I wrote before (two dependent classes: Calc.java Calcfunction.java). The code has been placed in GitHub.

Post part of the code:

1  Public classCalcextendsjavax.swing.jframe{2 3          PublicCalc () {4 initcomponents ();5         }6 7         Private voidinitcomponents () {8 java.awt.GridBagConstraints gridbagconstraints;9 Ten setdefaultcloseoperation (Javax.swing.WindowConstants.EXIT_ON_CLOSE); OneSettitle ("\u8ba1\u7b97\u5668"); ASetBounds (NewJava.awt.Rectangle (500, 50, 0, 0)); -Setresizable (false); -  the···//Interface Layout -  -                 } -                 //Main monitoring +ActionListener listenerequals =NewActionListener () { -              Public voidactionperformed (ActionEvent e) { +Formulastand.settext (edit + "="); AHaspoint =false; at String result; -                 Try { -result = Calcfunction.evaluate (edit+ "="); -}Catch(Exception E1) { -result = "Syntax error"; -                 } in                 if(double.parsedouble (result)%1 = = 0) { -Editstand.settext (String.valueof (int) (double.parsedouble (Result) )); to}Else{ +Editstand.settext (String.valueof (float) (double.parsedouble (Result) )); -                 } theEdit = "0"; *             } $         }; Panax Notoginseng}

Calc.java

Classes used for testing

Calcfunction.java

Unit tests are below

The first thing to do is to import it under this project JUnit Library Specific practices: Build path--Config build path ..... Add Libraries ... Select JUnit next-> Select junit 4 finished

Add complete

Creating test Cases

New--Java test Case Name:calcfunctiontest Next-> Select the method to test

Automatically generate a test class calcfunctiontest, which contains some empty test cases, @Test annotations. You only need to make these test cases slightly modified to use. The complete Calcfunctiontest code is as follows:

1  Packagecom.school.indivodial;2 3 Import Staticorg.junit.assert.*;4 5 ImportOrg.junit.Before;6 Importorg.junit.Test;7 8 /**9  * Ten  * @authorLendoon One The *calcfunction class is a function class of the Calc class, A *calc UI input infix expression called Calcfunction static Evaluate method evaluates the returned result -  */ -  Public classCalcfunctiontest { the      - @Test -      Public voidTestevaluate_basic ()throwsException { -Double expectedanswer = double.valueof ("90"); +Double actualanswer = double.valueof (Calcfunction.evaluate ("100-(22+6x3) ÷4=")); - assertequals (Expectedanswer, actualanswer); +     } A  at @Test -      Public voidTestevaluate_pow ()throwsexception{ -Double expectedanswer = double.valueof ("1024"); -Double actualanswer = double.valueof (Calcfunction.evaluate ("2^10=")); - assertequals (Expectedanswer, actualanswer); -     } in      - @Test to      Public voidTESTEVALUATE_SQRT ()throwsexception{ +Double expectedanswer = double.valueof ("8"); -Double actualanswer = double.valueof (Calcfunction.evaluate ("√64=")); the assertequals (Expectedanswer, actualanswer); *     } $     Panax Notoginseng @Test -      Public voidTestevaluate_cos ()throwsexception{ theDouble expectedanswer = double.valueof ("1"); +Double actualanswer = double.valueof (Calcfunction.evaluate ("COS (0) =")); A assertequals (Expectedanswer, actualanswer); the     } +}

Calcfunctiontest.java

JUnit Test, Run as, results

The test shows that the green check mark is passed, showing the Blue Cross, indicating that the failure was not passed. The Testevaluate_cos test method in the.

Fails, the progress bar becomes reddish-brown, and there are two cases of failure:

When processing results with expected deviations (failure) and processing results, an exception is thrown directly-Test error (Error)

Two scenarios in which the test failed

When all tests are successful, the progress bar is green:

JUnit Best practices test for any possible errors. Unit tests are not meant to prove that you are right, but to prove that you are not wrong.

JUnit 4 Unit Test