prime-factors: convert to use instance methods

exercises/prime-factors/src/example/java/PrimeFactors.java → exercises/prime-factors/src/example/java/PrimeFactorsCalculator.java

@@ -1,9 +1,9 @@
 import java.util.ArrayList;
 import java.util.List;
 
-public class PrimeFactors {
+public class PrimeFactorsCalculator {
 
-    public static List<Long> getForNumber(long number) {
+    public List<Long> calculatePrimeFactorsOf(long number) {
         List<Long> primes = new ArrayList<>();
         long divisor = 2;
 

exercises/prime-factors/src/test/java/PrimeFactorsTest.java → exercises/prime-factors/src/test/java/PrimeFactorsCalculatorTest.java

@@ -1,17 +1,17 @@
 import org.junit.Test;
-import org.junit.Ignore;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
 import org.junit.runners.Parameterized.Parameters;
 
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import static org.junit.Assert.assertEquals;
 
 @RunWith(Parameterized.class)
-public class PrimeFactorsTest {
+public class PrimeFactorsCalculatorTest {
 
     private long input;
     private List<Long> expectedOutput;
@@ -19,9 +19,9 @@ public class PrimeFactorsTest {
     @Parameters(name="Prime factors of {0} = {1}")
     public static Collection<Object[]> data() {
         return Arrays.asList(new Object[][]{
-                {1L, Arrays.asList()},
-                {2L, Arrays.asList(2L)},
-                {3L, Arrays.asList(3L)},
+                {1L, Collections.emptyList()},
+                {2L, Collections.singletonList(2L)},
+                {3L, Collections.singletonList(3L)},
                 {4L, Arrays.asList(2L, 2L)},
                 {6L, Arrays.asList(2L, 3L)},
                 {8L, Arrays.asList(2L, 2L, 2L)},
@@ -33,14 +33,14 @@ public class PrimeFactorsTest {
         });
     }
 
-    public PrimeFactorsTest(long input, List<Long> expectedOutput) {
+    public PrimeFactorsCalculatorTest(long input, List<Long> expectedOutput) {
         this.input = input;
         this.expectedOutput = expectedOutput;
     }
 
-
     @Test
     public void test() {
-        assertEquals(expectedOutput, PrimeFactors.getForNumber(input));
+        assertEquals(expectedOutput, new PrimeFactorsCalculator().calculatePrimeFactorsOf(input));
     }
+
 }