From 07ab54c36d08ea8333cc304eab954ac99cf47735 Mon Sep 17 00:00:00 2001
From: kemalghifari <mkemalgr@gmail.com>
Date: Thu, 29 Oct 2020 15:31:17 +0100
Subject: [PATCH 1/5] first green test

---
 src/test/java/tdd/setup/CalculatorTest.java | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/test/java/tdd/setup/CalculatorTest.java b/src/test/java/tdd/setup/CalculatorTest.java
index 3bf16e9..15e335b 100644
--- a/src/test/java/tdd/setup/CalculatorTest.java
+++ b/src/test/java/tdd/setup/CalculatorTest.java
@@ -16,4 +16,16 @@ void calculatorCanDoTwoPlusTwo() {
         calc.pressEquals();
         assertEquals("4", calc.readScreen());
     }
+
+    @Test
+    @DisplayName("should display result after pressing clear key")
+    void calculatorCanDisplayZeroResult() {
+        Calculator calc = new Calculator();
+        calc.pressDigitKey(1);
+        calc.pressOperationKey("+");
+        calc.pressDigitKey(2);
+        calc.pressEquals();
+        calc.pressClearKey();
+        assertEquals("0", calc.readScreen());
+    }
 }

From 1d4cc193ed90c8634faea348404f1870835fdf23 Mon Sep 17 00:00:00 2001
From: kemalghifari <mkemalgr@gmail.com>
Date: Thu, 29 Oct 2020 15:35:07 +0100
Subject: [PATCH 2/5] first red test

---
 src/test/java/tdd/setup/CalculatorTest.java | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/test/java/tdd/setup/CalculatorTest.java b/src/test/java/tdd/setup/CalculatorTest.java
index 15e335b..1e89190 100644
--- a/src/test/java/tdd/setup/CalculatorTest.java
+++ b/src/test/java/tdd/setup/CalculatorTest.java
@@ -28,4 +28,18 @@ void calculatorCanDisplayZeroResult() {
         calc.pressClearKey();
         assertEquals("0", calc.readScreen());
     }
+
+    @Test
+    @DisplayName("should display result after multiplying two decimal numbers")
+    void calculatorCanDoZeroCommaTwoTimesZeroCommaThree() {
+        Calculator calc = new Calculator();
+        calc.pressDotKey();
+        calc.pressDigitKey(2);
+        calc.pressOperationKey("x");
+        calc.pressDotKey();
+        calc.pressDigitKey(3);
+        calc.pressEquals();
+        assertEquals("0.06", calc.readScreen());
+    }
 }
+

From fc6466985f3f1e0b95264bcfb36fa4b8e66d61f4 Mon Sep 17 00:00:00 2001
From: kemalghifari <mkemalgr@gmail.com>
Date: Thu, 29 Oct 2020 15:49:10 +0100
Subject: [PATCH 3/5] fixed bug in the first red test

---
 src/main/java/tdd/setup/Calculator.java | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/main/java/tdd/setup/Calculator.java b/src/main/java/tdd/setup/Calculator.java
index 171f6d6..7565061 100644
--- a/src/main/java/tdd/setup/Calculator.java
+++ b/src/main/java/tdd/setup/Calculator.java
@@ -19,7 +19,11 @@ public void pressDigitKey(int digit) {
             screen = screen + digit;
         } else {
             latestValue = Double.parseDouble(screen);
-            screen = Integer.toString(digit);
+            if(!screen.contains(".")){
+                screen = Integer.toString(digit);
+            } else {
+                screen = "0" + "." + digit;
+            }
         }
     }
 
@@ -34,7 +38,7 @@ public void pressOperationKey(String operation)  {
     }
 
     public void pressDotKey() {
-        if(!screen.endsWith(".")) screen = screen + ".";
+        if(!screen.contains(".")) screen = screen + ".";
     }
 
     public void pressNegative() {

From 5ae56326e015dbdd65952fadda14c309292a70e6 Mon Sep 17 00:00:00 2001
From: kemalghifari <mkemalgr@gmail.com>
Date: Thu, 29 Oct 2020 16:49:02 +0100
Subject: [PATCH 4/5] second red test

---
 src/test/java/tdd/setup/CalculatorTest.java | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/test/java/tdd/setup/CalculatorTest.java b/src/test/java/tdd/setup/CalculatorTest.java
index 1e89190..2133080 100644
--- a/src/test/java/tdd/setup/CalculatorTest.java
+++ b/src/test/java/tdd/setup/CalculatorTest.java
@@ -41,5 +41,17 @@ void calculatorCanDoZeroCommaTwoTimesZeroCommaThree() {
         calc.pressEquals();
         assertEquals("0.06", calc.readScreen());
     }
+
+    @Test
+    @DisplayName("should display result after multiplying a negative button with a positive number")
+    void calculatorCanDoNegativeButtonTimesThree() {
+        Calculator calc = new Calculator();
+        calc.pressNegative();
+        calc.pressOperationKey("x");
+        calc.pressDigitKey(3);
+        calc.pressEquals();
+        assertEquals("0", calc.readScreen());
+    }
 }
 
+

From 6be4afb78f3fdef2fddab5abdcce2ea01922a446 Mon Sep 17 00:00:00 2001
From: kemalghifari <mkemalgr@gmail.com>
Date: Thu, 29 Oct 2020 16:52:02 +0100
Subject: [PATCH 5/5] fixed bug of the second red test

---
 src/main/java/tdd/setup/Calculator.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/main/java/tdd/setup/Calculator.java b/src/main/java/tdd/setup/Calculator.java
index 7565061..e3cc4b9 100644
--- a/src/main/java/tdd/setup/Calculator.java
+++ b/src/main/java/tdd/setup/Calculator.java
@@ -43,6 +43,9 @@ public void pressDotKey() {
 
     public void pressNegative() {
         screen = screen.startsWith("-") ? screen.substring(1) : "-" + screen;
+        if (screen.equals("-" + "0")) {
+            screen = "0";
+        }
     }
 
     public void pressEquals() {