Inheritance and ctors.

oop/code/oop/pom.xml

@@ -25,6 +25,12 @@
       <version>4.11</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.24</version>
+      <scope>provided</scope>
+    </dependency>
   </dependencies>
 
   <build>

oop/code/oop/src/main/java/com/scaler/lld/scaler/Student.java

@@ -0,0 +1,33 @@
+package com.scaler.lld.scaler;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Getter
+@Setter
+@NoArgsConstructor
+public class Student extends User {
+
+    private String batchName;
+    private Integer psp;
+    private StudentStatus status = StudentStatus.ACTIVE; // ACTIVE, PAUSED, COMPLETED
+
+    // Define parametrised constructor
+
+    public Student(String name, String email, String batchName, Integer psp) {
+        super(name, email);
+        this.batchName = batchName;
+
+        if (psp < 0 || psp > 100) {
+            throw new IllegalArgumentException("PSP should be between 0 and 100");
+        }
+        this.psp = psp;
+    }
+
+    public void changeBatch(String batchName) {
+        this.batchName = batchName;
+    }
+
+
+}

oop/code/oop/src/main/java/com/scaler/lld/scaler/StudentStatus.java

@@ -0,0 +1,5 @@
+package com.scaler.lld.scaler;
+
+public enum StudentStatus {
+    ACTIVE, PAUSED, COMPLETED, EDGE
+}

oop/code/oop/src/main/java/com/scaler/lld/scaler/User.java

@@ -0,0 +1,19 @@
+package com.scaler.lld.scaler;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+public class User {
+    private String name;
+    private String email;
+
+    public void changeEmail(String email) {
+        this.email = email;
+    }
+}

oop/code/oop/src/test/java/com/scaler/lld/scaler/StudentTest.java

@@ -0,0 +1,50 @@
+package com.scaler.lld.scaler;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import org.junit.Test;
+
+public class StudentTest {
+
+    @Test
+    public void testDefaultCtor() {
+        Student student = new Student();
+
+        assertNotNull("If the ctor is called, then object must be returned",
+                student);
+        assertNull("If default ctor is used, name should be null", student.getName());
+        assertEquals("If default ctor is used, status should be active", StudentStatus.ACTIVE, student.getStatus());
+    }
+
+    @Test
+    public void testParametrisedCtor() {
+        Student student = new Student("John Doe", "john@doe.in", "Batch 1", 100);
+
+        assertNotNull("If the ctor is called, then object must be returned",
+                student);
+        assertEquals("If name ctor is passed to ctor, name should be set in instance", "John Doe", student.getName());
+        assertEquals("If status is not passed to ctor, status should be active", StudentStatus.ACTIVE,
+                student.getStatus());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testParametrisedCtorWithInvalidPsp() {
+        new Student("John Doe", "john@doe.in", "Batch 1", 101);
+    }
+
+    @Test
+    public void testParentFields() {
+        Student student = new Student("John Doe", "john@doe.in", "Batch 1", 100);
+        assertEquals("If name ctor is passed to ctor, name should be set in instance", "John Doe", student.getName());
+        
+        String newEmail = "john@doe.com";
+        student.changeEmail(newEmail);
+        assertEquals("If email is changed, then email should be updated", newEmail, student.getEmail());
+    }
+
+}
+
+// Coverage - % of code your test cases cover - 80%
+// pytest > junit