Section 2 - Comparable

src/main/java/com/zipcoder/payment/Check.java

@@ -62,8 +62,12 @@ public class Check implements Payment {
     public void setId(long id) {
         this.id = id;
     }
+
     public String getAccountNumber(){
         return this.accountNumber;
     }
 
+    public int compareTo(Payment o) {
+        return 0;
+    }
 }

src/main/java/com/zipcoder/payment/CreditCard.java

@@ -81,5 +81,17 @@ public class CreditCard implements Payment {
         return Integer.parseInt(lastFourString);
     }
 
+    public int compareTo(Payment o) {
 
+        int result = this.getShortDescription().compareTo(o.getShortDescription());
+
+        if(result > 0){
+            return 1;
+        } else if(result < 0){
+            return -1;
+        } else {
+            return 0;
+        }
+
+    }
 }

src/main/java/com/zipcoder/payment/Payment.java

@@ -1,6 +1,6 @@
 package com.zipcoder.payment;
 
-public interface Payment {
+public interface Payment extends Comparable<Payment> {
 
     long getId();
 
@@ -8,5 +8,4 @@ public interface Payment {
 
     String getShortDescription();
 
-
 }

src/main/java/com/zipcoder/payment/Paypal.java

@@ -47,5 +47,7 @@ public class Paypal implements Payment {
         return sb.toString();
     }
 
-
+    public int compareTo(Payment o) {
+        return 0;
+    }
 }

src/test/java/com/zipcoder/payment/CheckTest.java

@@ -141,4 +141,8 @@ class CheckTest {
         String actual = ck.getShortDescription();
         assertEquals(expected, actual);
     }
+
+    @Test
+    void compareTo() {
+    }
 }

src/test/java/com/zipcoder/payment/CreditCardTest.java

@@ -154,4 +154,19 @@ public class CreditCardTest {
 
     }
 
+    @Test
+    public void compareToTest() {
+        //Given
+        Payment cc = new CreditCard(12, 4111131,"Nicholas Maidanos", 4, 11);
+        Payment pp = new Paypal(23, "Nicholas Maidanos", "nmaidanos@gmail.com");
+
+        //Expect
+        int expected = -1;
+
+        //Actual
+        int actual = cc.compareTo(pp);
+
+        assertEquals(expected, actual);
+
+    }
 }

src/test/java/com/zipcoder/payment/PaypalTest.java

@@ -104,4 +104,8 @@ class PaypalTest {
 
         assertEquals(expect,actual);
     }
+
+    @Test
+    void compareTo() {
+    }
 }