Add tests for ByteUtil, flesh out other half of the split/join API.

arcadeutils/binary.py

@@ -303,7 +303,22 @@ class ByteUtil:
         ]
         return b''.join(chunks)
 
+    @staticmethod
+    def split16bithalves(data: bytes) -> Tuple[bytes, bytes]:
+        length = len(data)
+        return(
+            b''.join(data[x:(x + 2)] for x in range(0, length, 4)),
+            b''.join(data[(x + 2):(x + 4)] for x in range(0, length, 4)),
+        )
+
     @staticmethod
     def combine8bithalves(upper: bytes, lower: bytes) -> bytes:
         chunks = [bytes([upper[i], lower[i]]) for i in range(len(upper))]
         return b''.join(chunks)
+
+    @staticmethod
+    def split8bithalves(data: bytes) -> Tuple[bytes, bytes]:
+        return (
+            bytes([d for d in data[::2]]),
+            bytes([d for d in data[1::2]]),
+        )

tests/test_ByteUtil.py

@@ -0,0 +1,41 @@
+from arcadeutils import ByteUtil
+import unittest
+
+
+class TestBinaryDiff(unittest.TestCase):
+
+    def test_byteswap(self) -> None:
+        self.assertEqual(
+            ByteUtil.byteswap(b"abcd1234"),
+            b'badc2143',
+        )
+
+    def test_wordswap(self) -> None:
+        self.assertEqual(
+            ByteUtil.wordswap(b"abcd1234"),
+            b'dcba4321',
+        )
+
+    def test_combine8bithalves(self) -> None:
+        self.assertEqual(
+            ByteUtil.combine8bithalves(b"1234", b"abcd"),
+            b"1a2b3c4d",
+        )
+
+    def test_split8bithalves(self) -> None:
+        self.assertEqual(
+            ByteUtil.split8bithalves(b"1a2b3c4d"),
+            (b"1234", b"abcd"),
+        )
+
+    def test_combine16bithalves(self) -> None:
+        self.assertEqual(
+            ByteUtil.combine16bithalves(b"1234", b"abcd"),
+            b"12ab34cd",
+        )
+
+    def test_split16bithalves(self) -> None:
+        self.assertEqual(
+            ByteUtil.split16bithalves(b"1a2b3c4d"),
+            (b"1a3c", b"2b4d"),
+        )