From 9738221070d57cdf751045c14b93da3772e643cf Mon Sep 17 00:00:00 2001
From: haerong22 <haerong22@naver.com>
Date: Sun, 13 Mar 2022 17:05:34 +0900
Subject: [PATCH] refactoring : mutable data - combine functions into transform

---
 .../Client1.java                              | 14 ++++++++
 .../Client2.java                              | 21 +++++++++++
 .../Client3.java                              | 14 ++++++++
 .../EnrichReading.java                        |  4 +++
 .../Reading.java                              |  7 ++++
 .../ReadingClient.java                        | 27 ++++++++++++++
 .../before/Client1.java                       | 21 +++++++++++
 .../before/Client2.java                       | 31 ++++++++++++++++
 .../before/Client3.java                       | 25 +++++++++++++
 .../before/Reading.java                       |  7 ++++
 .../ReadingClientTest.java                    | 36 +++++++++++++++++++
 11 files changed, 207 insertions(+)
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client1.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client2.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client3.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/EnrichReading.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Reading.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClient.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client1.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client2.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client3.java
 create mode 100644 refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Reading.java
 create mode 100644 refactoring/src/test/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClientTest.java

diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client1.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client1.java
new file mode 100644
index 00000000..bc994705
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client1.java
@@ -0,0 +1,14 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform;
+
+public class Client1 extends ReadingClient {
+
+    double baseCharge;
+
+    public Client1(Reading reading) {
+        this.baseCharge = enrichReading(reading).baseCharge();
+    }
+
+    public double getBaseCharge() {
+        return baseCharge;
+    }
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client2.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client2.java
new file mode 100644
index 00000000..6927dae7
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client2.java
@@ -0,0 +1,21 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform;
+
+public class Client2 extends ReadingClient {
+
+    private double base;
+    private double taxableCharge;
+
+    public Client2(Reading reading) {
+        EnrichReading enrichReading = enrichReading(reading);
+        this.base = enrichReading.baseCharge();
+        this.taxableCharge = enrichReading.taxableCharge();
+    }
+
+    public double getBase() {
+        return base;
+    }
+
+    public double getTaxableCharge() {
+        return taxableCharge;
+    }
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client3.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client3.java
new file mode 100644
index 00000000..4d11c321
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Client3.java
@@ -0,0 +1,14 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform;
+
+public class Client3 extends ReadingClient{
+
+    private double basicChargeAmount;
+
+    public Client3(Reading reading) {
+        this.basicChargeAmount = enrichReading(reading).baseCharge();
+    }
+
+    public double getBasicChargeAmount() {
+        return basicChargeAmount;
+    }
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/EnrichReading.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/EnrichReading.java
new file mode 100644
index 00000000..0f0a43d8
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/EnrichReading.java
@@ -0,0 +1,4 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform;
+
+public record EnrichReading(Reading reading, double baseCharge, double taxableCharge) {
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Reading.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Reading.java
new file mode 100644
index 00000000..4fdaef93
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/Reading.java
@@ -0,0 +1,7 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform;
+
+import java.time.Month;
+import java.time.Year;
+
+public record Reading(String customer, double quantity, Month month, Year year) {
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClient.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClient.java
new file mode 100644
index 00000000..e3d76495
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClient.java
@@ -0,0 +1,27 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform;
+
+import java.time.Month;
+import java.time.Year;
+
+public class ReadingClient {
+
+    protected double taxThreshold(Year year) {
+        return 5;
+    }
+
+    protected double baseRate(Month month, Year year) {
+        return 10;
+    }
+
+    protected EnrichReading enrichReading(Reading reading) {
+        return new EnrichReading(reading, baseCharge(reading), taxableCharge(reading));
+    }
+
+    private double taxableCharge(Reading reading) {
+        return Math.max(0, baseCharge(reading) - taxThreshold(reading.year()));
+    }
+
+    private double baseCharge(Reading reading) {
+        return baseRate(reading.month(), reading.year()) * reading.quantity();
+    }
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client1.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client1.java
new file mode 100644
index 00000000..91ec1985
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client1.java
@@ -0,0 +1,21 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform.before;
+
+import java.time.Month;
+import java.time.Year;
+
+public class Client1 {
+
+    double baseCharge;
+
+    public Client1(Reading reading) {
+        this.baseCharge = baseRate(reading.month(), reading.year()) * reading.quantity();
+    }
+
+    private double baseRate(Month month, Year year) {
+        return 10;
+    }
+
+    public double getBaseCharge() {
+        return baseCharge;
+    }
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client2.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client2.java
new file mode 100644
index 00000000..64b23fa7
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client2.java
@@ -0,0 +1,31 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform.before;
+
+import java.time.Month;
+import java.time.Year;
+
+public class Client2 {
+
+    private double base;
+    private double taxableCharge;
+
+    public Client2(Reading reading) {
+        this.base = baseRate(reading.month(), reading.year()) * reading.quantity();
+        this.taxableCharge = Math.max(0, this.base - taxThreshold(reading.year()));
+    }
+
+    private double taxThreshold(Year year) {
+        return 5;
+    }
+
+    private double baseRate(Month month, Year year) {
+        return 10;
+    }
+
+    public double getBase() {
+        return base;
+    }
+
+    public double getTaxableCharge() {
+        return taxableCharge;
+    }
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client3.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client3.java
new file mode 100644
index 00000000..36aa009b
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Client3.java
@@ -0,0 +1,25 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform.before;
+
+import java.time.Month;
+import java.time.Year;
+
+public class Client3 {
+
+    private double basicChargeAmount;
+
+    public Client3(Reading reading) {
+        this.basicChargeAmount = calculateBaseCharge(reading);
+    }
+
+    private double calculateBaseCharge(Reading reading) {
+        return baseRate(reading.month(), reading.year()) * reading.quantity();
+    }
+
+    private double baseRate(Month month, Year year) {
+        return 10;
+    }
+
+    public double getBasicChargeAmount() {
+        return basicChargeAmount;
+    }
+}
diff --git a/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Reading.java b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Reading.java
new file mode 100644
index 00000000..fbf6bf55
--- /dev/null
+++ b/refactoring/src/main/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/before/Reading.java
@@ -0,0 +1,7 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform.before;
+
+import java.time.Month;
+import java.time.Year;
+
+public record Reading(String customer, double quantity, Month month, Year year) {
+}
diff --git a/refactoring/src/test/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClientTest.java b/refactoring/src/test/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClientTest.java
new file mode 100644
index 00000000..5111f17b
--- /dev/null
+++ b/refactoring/src/test/java/com/example/refactoring/_06_mutable_data/_22_combine_functions_into_transform/ReadingClientTest.java
@@ -0,0 +1,36 @@
+package com.example.refactoring._06_mutable_data._22_combine_functions_into_transform;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Month;
+import java.time.Year;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ReadingClientTest {
+
+    @Test
+    void client1() {
+        Client1 client1 = new Client1(acquireReading());
+        assertEquals(100d, client1.getBaseCharge());
+    }
+
+    @Test
+    void client2() {
+        Client2 client2 = new Client2(acquireReading());
+        assertEquals(100d, client2.getBase());
+        assertEquals(95d, client2.getTaxableCharge());
+    }
+
+    @Test
+    void client3() {
+        Client3 client3 = new Client3(acquireReading());
+        assertEquals(100d, client3.getBasicChargeAmount());
+    }
+
+
+    private Reading acquireReading() {
+        return new Reading("kim", 10, Month.MARCH, Year.of(2022));
+    }
+
+}
\ No newline at end of file