From e37112ddb4e140b621d41fb2208eb6f698aafa83 Mon Sep 17 00:00:00 2001
From: realphilip <pajach@pm.me>
Date: Thu, 29 Oct 2020 07:29:11 +0100
Subject: [PATCH 1/5] add green test for clear key

---
 src/test/java/tdd/setup/CalculatorTest.java | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/test/java/tdd/setup/CalculatorTest.java b/src/test/java/tdd/setup/CalculatorTest.java
index 3bf16e9..fd64a07 100644
--- a/src/test/java/tdd/setup/CalculatorTest.java
+++ b/src/test/java/tdd/setup/CalculatorTest.java
@@ -6,14 +6,26 @@
 
 @DisplayName("Retro calculator")
 class CalculatorTest {
+
+    private Calculator calc = new Calculator();
     @Test
     @DisplayName("should display result after adding two positive numbers")
     void calculatorCanDoTwoPlusTwo() {
-        Calculator calc = new Calculator();
         calc.pressDigitKey(2);
         calc.pressOperationKey("+");
         calc.pressDigitKey(2);
         calc.pressEquals();
         assertEquals("4", calc.readScreen());
     }
+
+    @Test
+    @DisplayName("should revert screen to 0")
+    void calculatorCanClearScreen(){
+        calc.pressDigitKey(2);
+        calc.pressOperationKey("+");
+        calc.pressDigitKey(2);
+        calc.pressEquals();
+        calc.pressClearKey();
+        assertEquals("0", calc.readScreen());
+    }
 }

From f0ecf305e7fcaf03dd04b1f68527edfd8c5afd4c Mon Sep 17 00:00:00 2001
From: realphilip <pajach@pm.me>
Date: Thu, 29 Oct 2020 07:30:45 +0100
Subject: [PATCH 2/5] add red test for ppercentage operator

---
 src/test/java/tdd/setup/CalculatorTest.java | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/test/java/tdd/setup/CalculatorTest.java b/src/test/java/tdd/setup/CalculatorTest.java
index fd64a07..eaccde2 100644
--- a/src/test/java/tdd/setup/CalculatorTest.java
+++ b/src/test/java/tdd/setup/CalculatorTest.java
@@ -28,4 +28,14 @@ void calculatorCanClearScreen(){
         calc.pressClearKey();
         assertEquals("0", calc.readScreen());
     }
+
+    @Test
+    @DisplayName("should move decimal point two spaces forward")
+    void calculatorCanDecimalizePercentages(){
+        calc.pressDigitKey(8);
+        calc.pressDigitKey(9);
+        calc.pressDigitKey(8);
+        calc.pressOperationKey("%");
+        assertEquals("8.98", calc.readScreen());
+    }
 }

From b0b00bc445e7a0ce79c6c919ecf8836259f2d459 Mon Sep 17 00:00:00 2001
From: realphilip <pajach@pm.me>
Date: Thu, 29 Oct 2020 07:34:36 +0100
Subject: [PATCH 3/5] fix for percentage operator, test now green

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

diff --git a/src/main/java/tdd/setup/Calculator.java b/src/main/java/tdd/setup/Calculator.java
index 171f6d6..ff29f04 100644
--- a/src/main/java/tdd/setup/Calculator.java
+++ b/src/main/java/tdd/setup/Calculator.java
@@ -43,6 +43,7 @@ public void pressNegative() {
 
     public void pressEquals() {
         var result = switch(latestOperation) {
+            case "%" -> latestValue / 100;
             case "+" -> latestValue + Double.parseDouble(screen);
             case "-" -> latestValue - Double.parseDouble(screen);
             case "x" -> latestValue * Double.parseDouble(screen);

From 6e066bf2166237882ed828b14ba2253c315147a6 Mon Sep 17 00:00:00 2001
From: realphilip <pajach@pm.me>
Date: Thu, 29 Oct 2020 07:45:27 +0100
Subject: [PATCH 4/5] add red test for negative number functionality

---
 src/test/java/tdd/setup/CalculatorTest.java | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/test/java/tdd/setup/CalculatorTest.java b/src/test/java/tdd/setup/CalculatorTest.java
index eaccde2..eda6eb6 100644
--- a/src/test/java/tdd/setup/CalculatorTest.java
+++ b/src/test/java/tdd/setup/CalculatorTest.java
@@ -38,4 +38,14 @@ void calculatorCanDecimalizePercentages(){
         calc.pressOperationKey("%");
         assertEquals("8.98", calc.readScreen());
     }
+
+    @Test
+    @DisplayName ("if the negative key is pressed before the input of a number, the number should turn negative")
+    void calculatorCanDisplayNegativeNumbers () {
+        calc.pressClearKey();
+        calc.pressNegative();
+        calc.pressDigitKey(8);
+        calc.pressDigitKey(8);
+        assertEquals("-88", calc.readScreen());
+    }
 }

From 97bab6047c47775637560eaed2547063e96c7448 Mon Sep 17 00:00:00 2001
From: realphilip <pajach@pm.me>
Date: Thu, 29 Oct 2020 07:49:57 +0100
Subject: [PATCH 5/5] fix for displaying negative numbers

---
 src/main/java/tdd/setup/Calculator.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/main/java/tdd/setup/Calculator.java b/src/main/java/tdd/setup/Calculator.java
index ff29f04..286e509 100644
--- a/src/main/java/tdd/setup/Calculator.java
+++ b/src/main/java/tdd/setup/Calculator.java
@@ -38,7 +38,9 @@ public void pressDotKey() {
     }
 
     public void pressNegative() {
-        screen = screen.startsWith("-") ? screen.substring(1) : "-" + screen;
+        screen = screen.startsWith("-") ? screen.substring(1) : "-";
+
+
     }
 
     public void pressEquals() {