Return bytes instead of str

Closes https://github.com/datpy/merkle-tree-stream/issues/2.

CHANGELOG.rst

@@ -1,3 +1,12 @@
+Merkle_Tree_Stream 0.0.1a2 (2019-10-06)
+=======================================
+
+Bug Fixes
+---------
+
+- MerkleTreeIterator leaf and parent functions now return bytes.
+
+
 Merkle_Tree_Stream 0.0.1a1 (2019-08-07)
 =======================================
 

merkle_tree_stream/node.py

@@ -23,7 +23,7 @@ class MerkleTreeNode:
     parent: int
     size: int
     data: bytes
-    hash: Optional[str] = attr.Factory(str)
+    hash: Optional[bytes] = attr.Factory(bytes)
 
     def __attrs_post_init__(self) -> Any:
         """Initialise the parent index."""

merkle_tree_stream/tree.py

@@ -7,8 +7,6 @@ from flat_tree import FlatTreeAccessor
 
 from merkle_tree_stream.node import MerkleTreeNode
 
-Hash = str
-
 EMPTY_DATA = b''
 EMPTY_HASH = None
 
@@ -26,8 +24,8 @@ class MerkleTreeIterator:
     :param roots: The tree roots
     """
 
-    leaf: Callable[[MerkleTreeNode], Hash]
-    parent: Callable[[MerkleTreeNode, MerkleTreeNode], Hash]
+    leaf: Callable[[MerkleTreeNode], bytes]
+    parent: Callable[[MerkleTreeNode, MerkleTreeNode], bytes]
     roots: List[MerkleTreeNode] = attr.Factory(list)
 
     _position: int = 0

test/conftest.py

@@ -6,7 +6,7 @@ import pytest
 @pytest.fixture
 def leaf():
     def _leaf(node, roots=None):
-        return hashlib.sha256(node.data).hexdigest()
+        return hashlib.sha256(node.data).digest()
 
     return _leaf
 
@@ -17,6 +17,6 @@ def parent():
         sha256 = hashlib.sha256()
         sha256.update(first.data)
         sha256.update(second.data)
-        return sha256.hexdigest()
+        return sha256.digest()
 
     return _parent

test/test_tree.py

@@ -17,26 +17,18 @@ def test_hashes(leaf, parent):
     assert len(merkle_iter) == expected_count
 
     assert next(merkle_iter) == MerkleTreeNode(
-        index=0,
-        parent=1,
-        hash=hashlib.sha256(b'a').hexdigest(),
-        size=1,
-        data=b'a',
+        index=0, parent=1, hash=hashlib.sha256(b'a').digest(), size=1, data=b'a'
     )
 
     assert next(merkle_iter) == MerkleTreeNode(
-        index=2,
-        parent=1,
-        hash=hashlib.sha256(b'b').hexdigest(),
-        size=1,
-        data=b'b',
+        index=2, parent=1, hash=hashlib.sha256(b'b').digest(), size=1, data=b'b'
     )
 
     hashed = hashlib.sha256(b'a')
     hashed.update(b'b')
 
     assert next(merkle_iter) == MerkleTreeNode(
-        index=1, parent=3, hash=hashed.hexdigest(), size=2, data=b''
+        index=1, parent=3, hash=hashed.digest(), size=2, data=b''
     )
 
     with pytest.raises(StopIteration):