Added some tests

src/main/java/nl/sander/beejava/TypeMapper.java

@@ -17,10 +17,10 @@ public class TypeMapper {
         MAP.put(short.class, "S");
         MAP.put(boolean.class, "Z");
     }
-
+//TODO something with arrays
     public static String map(Class<?> type) {
         return Optional.ofNullable(MAP.get(type))
-                .orElseThrow(() -> new RuntimeException("Type " + type.getName() + " not found")); // this MUST not happen -> TODO map all types
+                .orElseThrow(() -> new RuntimeException("Type " + type.getName() + " not found"));
     }
 
 

src/main/java/nl/sander/beejava/constantpool/entry/ConstantPoolEntry.java

@@ -25,7 +25,7 @@ public abstract class ConstantPoolEntry {
      *
      * @return a byte indicating the type of the constant
      */
-    byte getTag(){
+    byte getTag() {
         return getBytes()[0];
     }
 
@@ -58,10 +58,10 @@ public abstract class ConstantPoolEntry {
      * @return upper 8 bits as byte
      */
     protected byte upperByte(int u16) {
-        return (byte) (u16 << 8);
+        return (byte) (u16 >>> 8);
     }
 
     protected byte getByte(long bits, int positions) {
-        return (byte) ((bits >>> positions) & 0xFF);
+        return (byte) ((bits >>> (positions * 8)) & 0xFF);
     }
 }

src/main/java/nl/sander/beejava/constantpool/entry/DoubleEntry.java

@@ -13,8 +13,9 @@ public class DoubleEntry extends LeafEntry {
     @Override
     public byte[] getBytes() {
         long bits = Double.doubleToRawLongBits(doubleVal);
-        return new byte[]{TAG, getByte(bits, 56), getByte(bits, 48), getByte(bits, 40), getByte(bits, 32),
+        return new byte[]{TAG, getByte(bits, 7), getByte(bits, 6), getByte(bits, 5),
-                getByte(bits, 24), getByte(bits, 16), getByte(bits, 8), (byte) (bits & 0xFF)};
+                getByte(bits, 4),
+                getByte(bits, 3), getByte(bits, 2), getByte(bits, 1), (byte) (bits & 0xFF)};
     }
 
     @Override

src/main/java/nl/sander/beejava/constantpool/entry/LongEntry.java

@@ -18,8 +18,9 @@ public class LongEntry extends LeafEntry {
 
     @Override
     public byte[] getBytes() {
-        return new byte[]{TAG, getByte(longVal, 56), getByte(longVal, 48), getByte(longVal, 40), getByte(longVal, 32),
+        return new byte[]{TAG, getByte(longVal, 7), getByte(longVal, 6), getByte(longVal, 5),
-                getByte(longVal, 24), getByte(longVal, 16), getByte(longVal, 8), (byte) (longVal & 0xFF)};
+                getByte(longVal, 4), getByte(longVal, 3), getByte(longVal, 2),
+                getByte(longVal, 1), (byte) (longVal & 0xFF)};
     }
 
     @Override

src/test/java/nl/sander/beejava/constantpool/entry/ConstantPoolEntryTest.java

@@ -0,0 +1,32 @@
+package nl.sander.beejava.constantpool.entry;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ConstantPoolEntryTest {
+
+    private final ConstantPoolEntry entry = new ConstantPoolEntry() {
+        @Override
+        public byte[] getBytes() {
+            return new byte[]{};
+        }
+    };
+
+    @Test
+    public void getSetIndex() {
+        int value = 2;
+        entry.setIndex(value);
+        assertEquals(value, entry.getIndex());
+    }
+
+    @Test
+    public void lowerByte() {
+        assertEquals(1, entry.lowerByte(257));
+    }
+
+    @Test
+    public void upperByte() {
+        assertEquals(1, entry.upperByte(257));
+    }
+}

src/test/java/nl/sander/beejava/constantpool/entry/DoubleEntryTest.java

@@ -0,0 +1,13 @@
+package nl.sander.beejava.constantpool.entry;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+class DoubleEntryTest {
+
+    @Test
+    void getBytes() {
+        assertArrayEquals(new byte[]{6, 64, 40, 0, 0, 0, 0, 0, 0}, new DoubleEntry(12D).getBytes());
+    }
+}

src/test/java/nl/sander/beejava/constantpool/entry/FloatEntryTest.java

@@ -0,0 +1,13 @@
+package nl.sander.beejava.constantpool.entry;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+class FloatEntryTest {
+
+    @Test
+    void getBytes() {
+        assertArrayEquals(new byte[]{4, 0, 0, 0, 0}, new FloatEntry(0F).getBytes());
+    }
+}

src/test/java/nl/sander/beejava/constantpool/entry/IntegerEntryTest.java

@@ -0,0 +1,13 @@
+package nl.sander.beejava.constantpool.entry;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+class IntegerEntryTest {
+
+    @Test
+    void getBytes() {
+        assertArrayEquals(new byte[]{3, 18, 52, 86, 120}, new IntegerEntry(0x12345678).getBytes());
+    }
+}

src/test/java/nl/sander/beejava/constantpool/entry/LongEntryTest.java

@@ -0,0 +1,13 @@
+package nl.sander.beejava.constantpool.entry;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+class LongEntryTest {
+
+    @Test
+    void getBytes() {
+        assertArrayEquals(new byte[]{5, 18, 52, 86, 120, -102, -68, -34, -16}, new LongEntry(0x123456789ABCDEF0L).getBytes());
+    }
+}