style: remove asserts from bytes_utils.int_to_bytes (#72)

* style: remove `assert`s from `bytes_utils.int_to_bytes` 

* style: tidy-up things

* chore: bump version to `0.11.0`

---------

Co-authored-by: Piotr Idzik <[email protected]>

puzzle_generator/bytes_utils.py

@@ -4,15 +4,19 @@
 BYTEORDER: typing.Literal["little", "big"] = "little"
 
 
-def int_to_bytes(in_value: int) -> bytes:
-    assert in_value >= 0  # nosec B101
+def byte_length(in_value: int) -> int:
+    if in_value < 0:
+        raise ValueError("in_value must be non-negative")
     number_of_bytes = in_value.bit_length() // 8
     if 8 * number_of_bytes < in_value.bit_length():
         number_of_bytes += 1
-    assert number_of_bytes <= 256  # nosec B101
-    assert (
-        number_of_bytes - 1 <= in_value.bit_length() // 8 <= number_of_bytes
-    )  # nosec B101
+    return number_of_bytes
+
+
+def int_to_bytes(in_value: int) -> bytes:
+    number_of_bytes = byte_length(in_value)
+    if number_of_bytes > 255:
+        raise ValueError("in_value must be 255 bytes or less")
     return number_of_bytes.to_bytes(length=1, byteorder=BYTEORDER) + in_value.to_bytes(
         length=number_of_bytes, byteorder=BYTEORDER
     )

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "puzzle-generator"
-version = "0.10.2"
+version = "0.11.0"
 description = "Generates python code representing a puzzle"
 authors = ["piotr.idzik <[email protected]>"]
 readme = "./puzzle_generator/README.md"

tests/test_bytes_utils.py

@@ -7,12 +7,40 @@
 
 
 @pytest.mark.parametrize(
-    "in_value", [0, 1, 2, 3, 255, 256, 257, 3239949409384, 10**570]
+    ("in_value", "expected"),
+    [
+        (0, 0),
+        (1, 1),
+        (2, 1),
+        (3, 1),
+        (255, 1),
+        (256, 2),
+        (257, 2),
+        (2 ** (8 * 255) - 1, 255),
+        (2 ** (8 * 255), 256),
+    ],
+)
+def test_byte_length(in_value, expected):
+    assert bu.byte_length(in_value) == expected
+
+
+def test_byte_length_raises_for_negative_input():
+    with pytest.raises(ValueError, match="in_value must be non-negative"):
+        bu.byte_length(-1)
+
+
+@pytest.mark.parametrize(
+    "in_value", [0, 1, 2, 3, 255, 256, 257, 3239949409384, 10**570, 2 ** (8 * 255) - 1]
 )
 def test_int_to_bytes(in_value):
     assert bu.bytes_to_int(bu.int_to_bytes(in_value)) == in_value
 
 
+def test_int_to_bytes_raises_when_input_is_too_big():
+    with pytest.raises(ValueError, match="in_value must be 255 bytes or less"):
+        bu.int_to_bytes(2 ** (8 * 255))
+
+
 @pytest.mark.parametrize(
     ("in_str", "in_bytes"), itertools.product(utils.STRS, utils.BYTES_LIST)
 )