Hausaufgabe 2

src/main/java/tdd/setup/Calculator.java

@@ -1,5 +1,6 @@
 package tdd.setup;
 
+
 // behaviour inspired by https://www.online-calculator.com/
 public class Calculator {
 
@@ -18,8 +19,12 @@ public void pressDigitKey(int digit) {
         if(latestOperation.isEmpty()) {
             screen = screen + digit;
         } else {
-            latestValue = Double.parseDouble(screen);
-            screen = Integer.toString(digit);
+             if (latestValue == 0) {
+                 latestValue = Double.parseDouble(screen);
+                 screen = "0";
+             }
+           screen = screen + digit;
+
         }
     }
 
@@ -47,6 +52,7 @@ public void pressEquals() {
             case "-" -> latestValue - Double.parseDouble(screen);
             case "x" -> latestValue * Double.parseDouble(screen);
             case "/" -> latestValue / Double.parseDouble(screen);
+            case "" -> latestValue = Double.parseDouble(screen);
             default -> throw new IllegalArgumentException();
         };
         screen = Double.toString(result);

src/main/main.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/java" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

src/test/java/tdd/setup/CalculatorTest.java

@@ -16,4 +16,35 @@ void calculatorCanDoTwoPlusTwo() {
         calc.pressEquals();
         assertEquals("4", calc.readScreen());
     }
+    @Test
+    @DisplayName("mein test")
+    void calculatorCanDoTwoMinusTwo() {
+        Calculator calc = new Calculator();
+        calc.pressDigitKey(2);
+        calc.pressOperationKey("-");
+        calc.pressDigitKey(2);
+        calc.pressEquals();
+        assertEquals("0", calc.readScreen());
+    }
+    @Test
+    @DisplayName("mein test")
+    void calculatorCanDoEightyPlusTwenty() {
+        Calculator calc = new Calculator();
+        calc.pressDigitKey(8);
+        calc.pressDigitKey(0);
+        calc.pressOperationKey("+");
+        calc.pressDigitKey(2);
+        calc.pressDigitKey(0);
+        calc.pressEquals();
+        assertEquals("100", calc.readScreen());
+    }
+    @Test
+    @DisplayName("mein test")
+    void calculatorCanDoJustTwo() {
+        Calculator calc = new Calculator();
+        calc.pressDigitKey(2);
+        calc.pressEquals();
+        assertEquals("2", calc.readScreen());
+    }
+
 }

src/test/test.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/java" isTestSource="true" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>