can anybody give the unit test for the method in java

Question

public class This {
    int a;

    void data() {
        int a = 10;
        this.a = 200;      // this keyword current object variable access
        System.out.println("a=" + a);
    }

    public static void main(String args[]) {

        This t = new This();

        t.data();
        System.out.println("a=" + t.a);

    }

}

//junit test for data() method

Answer 1

Here an simple test using junit and assertJ

import org.assertj.core.api.Assertions;

@Test
public void testIt(){
   This t = new This();
   t.data();
   Assertions.assertThat(t.a)
      .isEqualTo(200);
}

Please note, that your a field should have either public visibility or method accessor (like getA() method).

A few unit-testing best practices articles:

• https://www.partech.nl/nl/publicaties/2020/03/10-unit-testing-best-practices#
• https://www.simform.com/blog/unit-testing-best-practices/
• https://www.toptal.com/qa/how-to-write-testable-code-and-why-it-matters