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student:junit:v4 [2018/08/10 14:25] – bernstdhstudent:junit:v4 [2018/08/14 11:00] (current) – bernstdh
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-===== JUnit Basics =====+===== JUnit v4 Basics =====
  
  
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-JUnit is an open-source testing framework. It provides a way to write,   organize, and run repeatable test.+JUnit is an open-source testing framework. It provides a way to write,   organize, and run repeatable test. This page provides a brief introduction to v4. Information is also available about  
 +[[student:junit:v5 | version 5 (Jupiter) ]].
  
  
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-For each class you want to test, you must create a file named   //ClassName//Test.java where //ClassName// denotes the name   of the class being tested. So, for example, if you want to test the   class named   ''%%Atom%%'' you must create a file named ''%%AtomTest.java%%''.+For each class you want to test, you must create a file. It is common to use naming system //ClassName//Test.java where //ClassName// denotes the name   of the class being tested. So, for example, if you want to test the   class named   ''%%Atom%%'' you would create a file named ''%%AtomTest.java%%''.
  
  
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 import static org.junit.Assert.*; import static org.junit.Assert.*;
  
-import org.junit.Before; 
 import org.junit.Test; import org.junit.Test;
  
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 (Note: The ''%%import static%%'' allows you to refer to   static members in the ''%%org.junit.Assert%%'' package without having   to include the class name.) (Note: The ''%%import static%%'' allows you to refer to   static members in the ''%%org.junit.Assert%%'' package without having   to include the class name.)
    
-The file //ClassName//Test.java contains methods that can be   used to test the class defined in //ClassName//.java.  Each such   method is preceeded by an ''%%@Test%%'' annotation.  (Note: An   annotation provides information about a program but is not part of   the program. Annotations have no effect on the operation of the   program.  Instead, they are used to provide information to tools   that might use the program as input.)+The file //ClassName//Test.java contains methods that can be   used to test the class defined in //ClassName//.java.  Each such   method is preceded by an ''%%@Test%%'' annotation.  (Note: An   annotation provides information about a program but is not part of   the program. Annotations have no effect on the operation of the   program.  Instead, they are used to provide information to tools   that might use the program as input.)
  
 So, still continuing with the example   above, if the ''%%Atom%%'' class contains a ''%%public int   getAtomicNumber()%%'' method, then ''%%AtomTest.java%%''   might include the following method:  So, still continuing with the example   above, if the ''%%Atom%%'' class contains a ''%%public int   getAtomicNumber()%%'' method, then ''%%AtomTest.java%%''   might include the following method: 
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     }     }
 </code> </code>
 +
 +Note that the name of this method is completely arbitrary, but, as always, descriptive names are always a good
 +idea. Some people simply use the name of the method being tested (as above), while others add a prefix or suffix that includes some form of the word "test" (e.g., ''%%testGetAtomicNumber()%%'', ''%%getAtomicNumber_Test()%%'',
 +etc...).
  
 The body of the methods in the //ClassName//Test.java must contain   the test cases for the corresponding methods in the //ClassName//   class.  These test cases often involve some "setup" code and a call to   the ''%%Assert.assertEquals()%%'' method. So, for example, the   ''%%getAtomicNumber%%'' method in the ''%%Atom%%'' class is   supposed to return the atomic number of the calling ''%%Atom%%''   object. To partially test this method one might implement the   ''%%testGetAtomicNumber()%%'' method in the   ''%%AtomTest%%'' class as follows: The body of the methods in the //ClassName//Test.java must contain   the test cases for the corresponding methods in the //ClassName//   class.  These test cases often involve some "setup" code and a call to   the ''%%Assert.assertEquals()%%'' method. So, for example, the   ''%%getAtomicNumber%%'' method in the ''%%Atom%%'' class is   supposed to return the atomic number of the calling ''%%Atom%%''   object. To partially test this method one might implement the   ''%%testGetAtomicNumber()%%'' method in the   ''%%AtomTest%%'' class as follows:
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 </code> </code>
    
-In the "setup" portion, this method creates an ''%%Atom%%''   objects (for oxygen). It then calls the   ''%%Assert.assertEquals()%%'' method to tell jUnit to do some testing.   This particular version of the ''%%Assert.assertEquals()%%'' method is   passed three parameters and has the following syntax:+In the "setup" portion, this method creates an ''%%Atom%%''   objects (for oxygen). It then calls the   ''%%Assert.assertEquals()%%'' method to tell JUnit to do some testing.   This particular version of the ''%%Assert.assertEquals()%%'' method is   passed three parameters and has the following syntax:
  
 ''Assert.assertEquals(//Description//, //ExpectedValue//, //ActualValue//);'' ''Assert.assertEquals(//Description//, //ExpectedValue//, //ActualValue//);''
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     public void testEquals()     public void testEquals()
     {     {
-        Atom    h, o;+        Atom    h, hh, o;
      
         h  = new Atom("H", 1, 1);         h  = new Atom("H", 1, 1);
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 When using ''%%Assert.assertEquals()%%'' to compare floating   point numbers (e.g., ''%%double%%'' values), one must remember   that the ''%%==%%'' operator must be used with care   because of the less-than-perfect precision of operations   on ''%%double%%'' values.  In JUnit, the implication of this is   that one should check to see if ''%%double%%'' values are   within a tolerance value of each other.  Hence, when   comparing ''%%double%%'' values one should use the following: When using ''%%Assert.assertEquals()%%'' to compare floating   point numbers (e.g., ''%%double%%'' values), one must remember   that the ''%%==%%'' operator must be used with care   because of the less-than-perfect precision of operations   on ''%%double%%'' values.  In JUnit, the implication of this is   that one should check to see if ''%%double%%'' values are   within a tolerance value of each other.  Hence, when   comparing ''%%double%%'' values one should use the following:
  
-Assert.assertEquals(//Description//, //ExpectedValue//, //ActualValue//, //tolerance//);+''Assert.assertEquals(//Description//, //ExpectedValue//, //ActualValue//, //tolerance//);''
  
  
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 <code> <code>
-javac -cp .;junit.jar;hamcrest-core.jar AtomTest.java+javac -cp .;junit.jar AtomTest.java
 java -cp .;junit.jar;hamcrest-core.jarorg.junit.runner.JUnitCore AtomTest java -cp .;junit.jar;hamcrest-core.jarorg.junit.runner.JUnitCore AtomTest
 </code> </code>