najlaa

src/main/java/htw/berlin/prog2/ha1/Calculator.java

@@ -81,6 +81,7 @@ public void pressUnaryOperationKey(String operation) {
             default -> throw new IllegalArgumentException();
         };
         screen = Double.toString(result);
+        if (screen.endsWith(".0")) screen = screen.substring(0, screen.length()-2);
         if(screen.equals("NaN")) screen = "Error";
         if(screen.contains(".") && screen.length() > 11) screen = screen.substring(0, 10);
 
@@ -105,6 +106,16 @@ public void pressDotKey() {
      * entfernt und der Inhalt fortan als positiv interpretiert.
      */
     public void pressNegativeKey() {
+        if ("Error".equals(screen)) return;
+        try {
+            double v = Double.parseDouble(screen);
+            if (v == 0.0) {
+                screen = "0";
+                return;
+            }
+        } catch (NumberFormatException e) {
+            return;
+        }
         screen = screen.startsWith("-") ? screen.substring(1) : "-" + screen;
     }
 
@@ -130,4 +141,4 @@ public void pressEqualsKey() {
         if(screen.endsWith(".0")) screen = screen.substring(0,screen.length()-2);
         if(screen.contains(".") && screen.length() > 11) screen = screen.substring(0, 10);
     }
-}
+}

src/test/java/htw/berlin/prog2/ha1/CalculatorTest.java

@@ -88,7 +88,50 @@ void testMultipleDecimalDots() {
         assertEquals(expected, actual);
     }
 
+    //grüner Test
+    @Test
+    @DisplayName("should convert integer to percent value")
+    void testConvertToPercentValue() {
+        Calculator calc = new Calculator();
+
+        calc.pressDigitKey(5);
+        calc.pressDigitKey(0);
+        calc.pressUnaryOperationKey("%");
+
+        String expected = "0.5";
+        String actual = calc.readScreen();
+
+        assertEquals(expected, actual);
+    }
+
+    //roter Test-01
+    @Test
+    @DisplayName("should not display negative zero")
+    void testNegativeZero() {
+        Calculator calc = new Calculator();
+
+        calc.pressDigitKey(0);
+        calc.pressNegativeKey();
 
-    //TODO hier weitere Tests erstellen
-}
+        String expected = "0";
+        String actual = calc.readScreen();
+
+        assertEquals(expected, actual);
+    }
+
+    //roter Test-02
+    @Test
+    @DisplayName("should trim .0 for unary results like sqrt")
+    void testTrimDotZeroForUnaryResults() {
+        Calculator calc = new Calculator();
+
+        calc.pressDigitKey(4);
+        calc.pressUnaryOperationKey("√");
+
+        String expected = "2";
+        String actual = calc.readScreen();
+
+        assertEquals(expected, actual);
+    }
 
+}