refactoring : primitive obsession - replace type code with subclasses

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/direct_inheritance/Employee.java

@@ -0,0 +1,29 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.direct_inheritance;
+
+public abstract class Employee {
+
+    private String name;
+
+    protected Employee(String name) {
+        this.name = name;
+    }
+
+    public static Employee createEmployee(String name, String type) {
+        return switch (type) {
+            case "engineer" -> new Engineer(name);
+            case "manager" -> new Manager(name);
+            case "salesman" -> new Salesman(name);
+            default -> throw new IllegalArgumentException(type);
+        };
+    }
+
+    protected abstract String getType();
+
+    @Override
+    public String toString() {
+        return "Employee{" +
+                "name='" + name + '\'' +
+                ", type='" + getType() + '\'' +
+                '}';
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/direct_inheritance/Engineer.java

@@ -0,0 +1,13 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.direct_inheritance;
+
+public class Engineer extends Employee {
+
+    public Engineer(String name) {
+        super(name);
+    }
+
+    @Override
+    public String getType() {
+        return "engineer";
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/direct_inheritance/Manager.java

@@ -0,0 +1,13 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.direct_inheritance;
+
+public class Manager extends Employee {
+
+    public Manager(String name) {
+        super(name);
+    }
+
+    @Override
+    public String getType() {
+        return "manager";
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/direct_inheritance/Salesman.java

@@ -0,0 +1,13 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.direct_inheritance;
+
+public class Salesman extends Employee {
+
+    public Salesman(String name) {
+        super(name);
+    }
+
+    @Override
+    public String getType() {
+        return "salesman";
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/direct_inheritance/_before/Employee.java

@@ -0,0 +1,35 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.direct_inheritance._before;
+
+import java.util.List;
+
+public class Employee {
+
+    private String name;
+
+    private String type;
+
+    public Employee(String name, String type) {
+        this.validate(type);
+        this.name = name;
+        this.type = type;
+    }
+
+    private void validate(String type) {
+        List<String> legalTypes = List.of("engineer", "manager", "salesman");
+        if (!legalTypes.contains(type)) {
+            throw new IllegalArgumentException(type);
+        }
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    @Override
+    public String toString() {
+        return "Employee{" +
+                "name='" + name + '\'' +
+                ", type='" + type + '\'' +
+                '}';
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/Employee.java

@@ -0,0 +1,34 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+public class Employee {
+
+    private String name;
+
+    private EmployeeType type;
+
+    public Employee(String name, String type) {
+        this.name = name;
+        this.type = this.employeeType(type);
+    }
+
+    private EmployeeType employeeType(String type) {
+        return switch (type) {
+            case "engineer" -> new Engineer();
+            case "manager" -> new Manager();
+            case "salesman" -> new Salesman();
+            default -> throw new IllegalArgumentException(type);
+        };
+    }
+
+    public String capitalizedType() {
+        return this.type.capitalizedType();
+    }
+
+    @Override
+    public String toString() {
+        return "Employee{" +
+                "name='" + name + '\'' +
+                ", type='" + type.toString() + '\'' +
+                '}';
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/EmployeeType.java

@@ -0,0 +1,7 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+public class EmployeeType {
+    public String capitalizedType() {
+        return this.toString().substring(0, 1).toUpperCase() + this.toString().substring(1).toLowerCase();
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/Engineer.java

@@ -0,0 +1,9 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+public class Engineer extends EmployeeType {
+
+    @Override
+    public String toString() {
+        return "engineer";
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/FullTimeEmployee.java

@@ -0,0 +1,7 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+public class FullTimeEmployee extends Employee {
+    public FullTimeEmployee(String name, String type) {
+        super(name, type);
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/Manager.java

@@ -0,0 +1,9 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+public class Manager extends EmployeeType {
+
+    @Override
+    public String toString() {
+        return "manager";
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/PartTimeEmployee.java

@@ -0,0 +1,7 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+public class PartTimeEmployee extends Employee {
+    public PartTimeEmployee(String name, String type) {
+        super(name, type);
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/Salesman.java

@@ -0,0 +1,9 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+public class Salesman extends EmployeeType {
+
+    @Override
+    public String toString() {
+        return "salesman";
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/_before/Employee.java

@@ -0,0 +1,35 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance._before;
+
+import java.util.List;
+
+public class Employee {
+
+    private String name;
+
+    private String type;
+
+    public Employee(String name, String type) {
+        this.validate(type);
+        this.name = name;
+        this.type = type;
+    }
+
+    private void validate(String type) {
+        List<String> legalTypes = List.of("engineer", "manager", "salesman");
+        if (!legalTypes.contains(type)) {
+            throw new IllegalArgumentException(type);
+        }
+    }
+
+    public String capitalizedType() {
+        return this.type.substring(0, 1).toUpperCase() + this.type.substring(1).toLowerCase();
+    }
+
+    @Override
+    public String toString() {
+        return "Employee{" +
+                "name='" + name + '\'' +
+                ", type='" + type + '\'' +
+                '}';
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/_before/FullTimeEmployee.java

@@ -0,0 +1,7 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance._before;
+
+public class FullTimeEmployee extends Employee {
+    public FullTimeEmployee(String name, String type) {
+        super(name, type);
+    }
+}

refactoring/src/main/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/_before/PartTimeEmployee.java

@@ -0,0 +1,7 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance._before;
+
+public class PartTimeEmployee extends Employee {
+    public PartTimeEmployee(String name, String type) {
+        super(name, type);
+    }
+}

refactoring/src/test/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/direct_inheritance/EmployeeTest.java

@@ -0,0 +1,16 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.direct_inheritance;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class EmployeeTest {
+
+    @Test
+    void employeeType() {
+        assertEquals("engineer", Employee.createEmployee("kim", "engineer").getType());
+        assertEquals("manager", Employee.createEmployee("lee", "manager").getType());
+        assertThrows(IllegalArgumentException.class, () -> Employee.createEmployee("park", "wrong type"));
+    }
+
+}

refactoring/src/test/java/com/example/refactoring/_11_primitive_obsession/_31_replace_type_code_with_subclasses/indirect_inheritance/EmployeeTest.java

@@ -0,0 +1,16 @@
+package com.example.refactoring._11_primitive_obsession._31_replace_type_code_with_subclasses.indirect_inheritance;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class EmployeeTest {
+
+    @Test
+    void capitalizedType() {
+        assertEquals("Manager", new FullTimeEmployee("kim", "manager").capitalizedType());
+        assertEquals("Engineer", new PartTimeEmployee("lee", "engineer").capitalizedType());
+        assertThrows(IllegalArgumentException.class, () -> new Employee("park", "wrong type"));
+    }
+
+}