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Я пытаюсь обернуть голову вокруг тестирования Junit и прочитать примеры, а что нет, но все же трудно понять, как и что тестировать. Ниже приведен класс с методами, из которых я создаю свои тестовые примеры (а также мой класс тестов).Направление с JUnit Testing
import java.util.Iterator;
/**
* The Probability class understands the likelihood that something will happen.
* <p>
* (c) Copyright Fred George 2008. All right reserved. Adapted and used for
* educational purposes with permission from Fred George.
* </p>
*
* @author Fred George
*/
public class Probability {
/** Value of receiver. */
private final double value;
/** Cannot happen. */
private static final double IMPOSSIBLE_VALUE = 0.0;
/** Will happen. */
private static final double CERTAIN_VALUE = 1.0;
/** Instance that represents outcome that will happen. */
public static final Probability CERTAIN = new Probability(CERTAIN_VALUE);
/**
* Answer a new instance of the receiver with the specified value as the
* likelihood that it occurs.
*
* @param valueAsFraction
* value between 0.0 and 1.0
* @throws
*/
public Probability(final double valueAsFraction) {
if (valueAsFraction < IMPOSSIBLE_VALUE || valueAsFraction > CERTAIN_VALUE) {
throw new IllegalArgumentException("Specified value of "
+ valueAsFraction + " is not between 0.0 and 1.0");
}
value = valueAsFraction;
}
/**
* Answer the liklihood that the receiver will occur and the specified other
* Probability will occur.
*
* @return "and" of receiver and other Probability
* @param other
* Probability being and'ed to receiver
*/
public final Probability and(final Probability other) {
return new Probability(this.value * other.value);
}
/**
* Answer the value of the receiver as a scaled double between 0.0
* (impossible) to 1.0 (certain).
* <p>
* This method is modeled after those in Double, Integer, and the rest of
* the wrapper classes.
*
* @return value of receiver as double between 0.0 and 1.0
*/
public final double doubleValue() {
return value;
}
/**
* Answer true if the receiver has the same value as the other (assuming
* other is a Probability).
*
* @return true if receiver's value equals other's value
* @param other
* Object (assumed to be Probability) to compare
*/
public final boolean equals(final Object other) {
if (!(other instanceof Probability)) {
return false;
}
return this.value == ((Probability) other).value;
}
/**
* Answers with a hashcode for the receiver.
* @return the hash
*/
public final int hashCode() {
return (new Double(this.value)).hashCode();
}
/**
* Answer true if the combined likelihoods of the specified Collection of
* Probabilities sums to certain (100%).
*
* @return true if combined likelihoods is 100%
* @param probabilities
* Collection of likelihoods to sum
*/
public static final boolean isTotalCertain(final java.util.Collection probabilities) {
double sum = 0;
for (Iterator i = probabilities.iterator(); i.hasNext();) {
sum += ((Probability) i.next()).value;
}
return sum == CERTAIN_VALUE;
}
/**
* Answer the liklihood that the receiver will not occur.
*
* @return "not" of receiver
*/
public final Probability not() {
return new Probability(CERTAIN_VALUE - value);
}
/**
* Answer the liklihood that the receiver will occur or the specified other
* Probability will occur, or both.
*
* @return "or" of receiver and other Probability
* @param other
* Probability being or'ed to receiver
*/
public final Probability or(final Probability other) {
return this.not().and(other.not()).not(); // DeMorgan's Law
}
/** Multiplier from double to percentage. */
private static final int PERCENTAGE_MULTIPLIER = 100;
/**
* Answers a String representation of the receiver suitable for debugging.
*
* @return String representation of the receiver
*/
public final String toString() {
int percentage = (int) (value * PERCENTAGE_MULTIPLIER);
return percentage + "%";
}
}
И вот что я предпринял для некоторых тестовых случаев. Я не пробовал их всех, но я придерживался метода «равно».
package edu.psu.ist.probability;
import edu.psu.ist.decision.Decision;
import junit.framework.TestCase;
import junit.framework.*;
public class ProbabilityTest extends TestCase {
private Probability p1;
private Probability p2;
private Probability p3;
private Decision d1;
protected void setUp() {
p1 = new Probability(.6);
p2 = new Probability(.7);
p3 = new Probability(.6);
d1 = new Decision("No decision made");
}
public void testHashCode() {
fail("Not yet implemented");
}
public void testProbability() {
assertEquals(p1.doubleValue(), .6);
try{
p1 = p3;
//get here, bad
fail("Should raise an IllegalArgumentException");
}catch (IllegalArgumentException e){
//good!
}
}
public void testAnd() {
assertEquals((p1.and(p2)).doubleValue(), .42);
}
public void testDoubleValue() {
assertEquals(p1.doubleValue(), .6);
}
public void testEqualsObject() {
assertEquals(p1, p3);
//assertEquals(p1, p2);
assertTrue(!p1.equals(p2));
assertTrue(p1.equals(p3));
/*Probability p1 = new Probability (.7);
Probability p2 = new Probability (.6);
Decision d1 = new Decision();
boolean TRUE = p1.equals(p2);
boolean FALSE = p1.equals(d1);
try {
p1.equals(p2);
p1.equals(d1);
p1.equals(null);
} catch (NullPointerException ex){
// exception should be thrown
}
// assertEquals("Return true if theses values are the same",p1.doubleValue(), p2.doubleValue());
// assertEquals("Return false if not equal", p1.doubleValue(), d1.equals(p1.doubleValue()));
// assertNotSame("Objects are not the same", p1, d1);
*/
}
public void testIsTotalCertain() {
fail("Not yet implemented");
}
public void testNot() {
fail("Not yet implemented");
}
public void testOr() {
fail("Not yet implemented");
}
public void testToString() {
fail("Not yet implemented");
}
}
Возможно, кто-то может пролить свет, который поможет мне понять этот процесс более четко.