Add new CompanyEmployee class and update tests for code clarity and…

… accuracy

Introduced a new class, `CompanyEmployee`, which implements both `Company` and `Employee` interfaces for a more structured and object-oriented approach. Updated `LazyErrorMessageTest` and `CompanyEmployeeTest` to reflect these changes. Moreover, the `getErrorMessage` method in `LazyErrorMessageTest` now accepts a parameter to provide a more accurate error message, thus improving debugging and readability.

src/main/java/interfaces/CompanyEmployee.java

@@ -0,0 +1,60 @@
+package interfaces;
+
+import java.util.Objects;
+
+// Java records became GA in Java 16
+// - immutable data holders
+// - autogenerate equals, hashCode, toString
+// - primary constructor that appears before the braces, as in
+//   record CompanyEmployee(String first, String last) implements Company, Employee {}
+// - can have other methods, but not modify the properties
+// - property "getters" match the property names, as in first() and last()
+public class CompanyEmployee implements Company, Employee {
+    private final String first;
+    private final String last;
+
+    public CompanyEmployee(String first, String last) {
+        this.first = first;
+        this.last = last;
+    }
+
+    public String getFirst() {
+        return first;
+    }
+
+    public String getLast() {
+        return last;
+    }
+
+    public String getName() {
+        return Employee.super.getName() + " works for " +
+               Company.super.getName();
+    }
+
+    public void doWork() {
+        System.out.println("Converting caffeine into code for $$$");
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) return true;
+        if (obj == null || obj.getClass() != this.getClass()) return false;
+        var that = (CompanyEmployee) obj;
+        return Objects.equals(this.first, that.first) &&
+               Objects.equals(this.last, that.last);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(first, last);
+    }
+
+    @Override
+    public String toString() {
+        return "CompanyEmployee[" +
+               "first=" + first + ", " +
+               "last=" + last + ']';
+    }
+
+
+}

src/test/java/interfaces/CompanyEmployeeTest.java

@@ -2,6 +2,8 @@
 
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 // Create a class called CompanyEmployee that implements both
 //   the Company and Employee interfaces
 // Implement the necessary methods
@@ -11,7 +13,7 @@ public class CompanyEmployeeTest {
 
     @Test
     public void getName() {
-//        CompanyEmployee emp = new CompanyEmployee("Peter", "Gibbons");
-//        assertEquals("Peter Gibbons works for Initech", emp.getName());
+        CompanyEmployee emp = new CompanyEmployee("Peter", "Gibbons");
+        assertEquals("Peter Gibbons works for Initech", emp.getName());
     }
 }

src/test/java/lambdas/LazyErrorMessageTest.java

@@ -6,20 +6,20 @@
 
 public class LazyErrorMessageTest {
 
-    private String getErrorMessage() {
+    private String getErrorMessage(boolean value) {
         System.out.println("Generating error message...");
-        return "x should be true";
+        return value + " should be true";
     }
 
     @Test
     void assertArgIsTrue() {
         boolean x = true;
-        assertTrue(x, getErrorMessage()); // 2nd arg is a String
+        assertTrue(x, getErrorMessage(x)); // 2nd arg is a String
     }
 
     @Test
     void assertArgIsTrue_lazyErrorMessage() {
         boolean x = true;
-        assertTrue(x, () -> getErrorMessage());  // 2nd arg is a Supplier<String>
+        assertTrue(x, () -> getErrorMessage(x));  // 2nd arg is a Supplier<String>
     }
 }