Triangle Checker

src/TriangleChecker.java

 import java.util.Scanner;
 
 public class TriangleChecker {
-  
+
   public enum TriangleType {
-    NONE, 
+    NONE,
     NORMAL,
     ISOSCELES,  // Gleichschenklig
     EQUILATERAL // Gleichseitig
     switch (type) {
       case NONE:
         System.out.println("Kein Dreieck");
-        break;        
+        break;
       case NORMAL:
         System.out.println("Dreieck");
-        break;        
+        break;
       case ISOSCELES:
         System.out.println("Gleichschenkliges Dreieck");
-        break;        
+        break;
       case EQUILATERAL:
         System.out.println("Gleichseitiges Dreieck");
-        break;        
+        break;
     }
   }
 
   // Analyse der Dreiecksart
   public static TriangleType checkTriangle(float a, float b, float c) {
+    if (a <= 0 || b <= 0 || c <= 0)
+      return TriangleType.NONE;
+
+    if (a + b > c && b + c > a && a + c > b) {
+      if (a == b && b == c) {
+        return TriangleType.EQUILATERAL;
+      }
+      if (a == b || a == c || b == c) {
+        return TriangleType.ISOSCELES;
+      }
+
+      return TriangleType.NORMAL;
+    }
+
     return TriangleType.NONE;
+
   }
 
+}
+
+
 
-}

test/TriangleCheckerTest.java

 import static org.junit.Assert.*;
 
 public class TriangleCheckerTest {
-    
+
     @Test
     public void testValidTriangle() {
 
 
     }
 
+    @Test
+    public void testUnvalidTriangle() {
+
+        // Arrange
+        float a = 1;
+        float b = 1;
+        float c = 100;
+
+        // Act
+        TriangleChecker.TriangleType type = TriangleChecker.checkTriangle(a, b, c);
+
+        // Assert
+        assertEquals(TriangleChecker.TriangleType.NONE, type);
+
+    }
+
+    @Test
+    public void testNegativeTriangle() {
+
+        // Arrange
+        float a = -2;
+        float b = 2;
+        float c = 3;
+
+        // Act
+        TriangleChecker.TriangleType type = TriangleChecker.checkTriangle(a, b, c);
+
+        // Assert
+        assertEquals(TriangleChecker.TriangleType.NONE, type);
+
+    }
+
+    @Test
+    public void testEquilateralTriangle() {
+
+        // Arrange
+        float a = 2;
+        float b = 2;
+        float c = 2;
+
+        // Act
+        TriangleChecker.TriangleType type = TriangleChecker.checkTriangle(a, b, c);
+
+        // Assert
+        assertEquals(TriangleChecker.TriangleType.EQUILATERAL, type);
+
+    }
+
+    @Test
+    public void testIsoscelesTriangle() {
+
+        // Arrange
+        float a = 3;
+        float b = 3;
+        float c = 4;
+
+        // Act
+        TriangleChecker.TriangleType type = TriangleChecker.checkTriangle(a, b, c);
+
+        // Assert
+        assertEquals(TriangleChecker.TriangleType.ISOSCELES, type);
+
+    }
+
+
+
+
 }