Enforce valid resource location names

litemapy/minecraft.py

@@ -32,7 +32,7 @@ def __init__(self, block_id: str, **properties: str) -> None:
         :param block_id:    the identifier of the block (e.g. *minecraft:stone*)
         :param properties:  the properties of the block state as keyword parameters (e.g. *facing="north"*)
         """
-        self.__block_id = block_id
+        self.__block_id = assert_valid_identifier(block_id)
         self.__properties = DiscriminatingDictionary(self.__validate, properties)
         self.__identifier_cache = None
 
@@ -53,7 +53,7 @@ def from_nbt(nbt: Compound) -> 'BlockState':
         """
         Reads a :class:`BlockState` from an nbt tag.
         """
-        block_id = str(nbt["Name"])
+        block_id = assert_valid_identifier(str(nbt["Name"]))
         if "Properties" in nbt:
             properties: dict[str, str] = {str(k): str(v) for k, v in nbt["Properties"].items()}
         else:
@@ -80,6 +80,7 @@ def with_id(self, block_id: str) -> 'BlockState':
 
         :param block_id:  the block id for the new :class:`BlockState`
         """
+        assert_valid_identifier(block_id)
         return BlockState(block_id, **self.__properties)
 
     def with_properties(self, **properties: Optional[str]) -> 'BlockState':
@@ -163,6 +164,7 @@ class Entity:
     (e.g. a sheep has a tag for its color and one indicating whether it has been sheared).
     """
 
+    _id: str
     _data: Compound
     _position: EntityPosition
     _rotation: EntityRotation
@@ -192,7 +194,7 @@ def __init__(self, str_or_nbt: Union[str, Compound]) -> None:
         if 'Motion' not in keys:
             self._data['Motion'] = List[Double]([Double(0.), Double(0.), Double(0.)])
 
-        self._id = self._data['id']
+        self._id = assert_valid_identifier(self._data['id'])
         position = [float(coord) for coord in self._data['Pos']]
         self._position = (position[0], position[1], position[2])
         rotation = [float(coord) for coord in self._data['Rotation']]
@@ -389,6 +391,45 @@ def position(self, position: BlockPosition):
             self._data[coord] = Int(self._position[index])
 
 
+def is_valid_identifier(identifier: str) -> bool:
+    """
+    Checks if a string is a valid identifier (aka. ResourceLocation in Mojmap).
+    """
+    # Check taken from Minecraft 1.20.1 ResourceLocation
+    allowed_chars = "_-abcdefghijklmnopqrstuvwxyz0123456789.:"
+    separator = False
+    for char in identifier:
+        if char not in allowed_chars:
+            return False
+        if char == ":":
+            # Now parsing the path part
+            separator = True
+            allowed_chars = "_-abcdefghijklmnopqrstuvwxyz0123456789./"
+    return separator
+
+
+class InvalidIdentifier(ValueError):
+    identifier: str
+
+    def __init__(self, identifier: str) -> None:
+        super().__init__(f'Invalid identifier "{identifier}"')
+
+
+def assert_valid_identifier(identifier: str) -> str:
+    """
+    Checks whether a string is a valid identifier (aka  ResourceLocation in Mojmap),
+    and raises InvalidIdentifierError if it is not.
+    The name "identifier" is from Yarn mappings but makes more sens in this context.
+
+    :returns: the identifier
+    :raises CorruptedSchematicError: if provided string is not a valid identifier
+    """
+
+    if not is_valid_identifier(identifier):
+        raise InvalidIdentifier(identifier)
+    return identifier
+
+
 class RequiredKeyMissingException(Exception):
 
     def __init__(self, key: str, message: str = 'The required key is missing in the (Tile)Entity\'s NBT Compound'):

tests/test_minecraft.py

@@ -1,15 +1,33 @@
+import pytest
+
 from litemapy import BlockState
+from litemapy.minecraft import is_valid_identifier
+from litemapy.minecraft import InvalidIdentifier
+from litemapy.schematic import AIR
 
 
 def test_blockstate_initialization():
-    # TODO Split into multiple smaller tests
     prop = {"test1": "testval", "test2": "testval2"}
     b = BlockState("minecraft:stone", **prop)
     assert len(prop) == len(b)
     for k, v in prop.items():
         assert b[k] == v
 
 
+def test_cannot_create_blockstate_with_invalid_id():
+    ids = (
+        "",
+        "minecraft stone",
+        "stone",
+        "minecraft:stone[property=value]",
+    )
+    for id_ in ids:
+        with pytest.raises(InvalidIdentifier):
+            BlockState(id_, prop="val")
+        with pytest.raises(InvalidIdentifier):
+            AIR.with_id(id_)
+
+
 def test_blockstate_nbt_is_identity():
     prop = {"test1": "testval", "test2": "testval2"}
     blockstate_1 = BlockState("minecraft:stone", **prop)
@@ -34,3 +52,16 @@ def test_blockstate_is_hashable():
     assert state1 == state2
     assert hash(state1) == hash(state2)
     assert hash(state1) == hash(state1)
+
+
+def test_is_valid_identifier():
+    assert is_valid_identifier("minecraft:air")
+    assert is_valid_identifier("minecraft:stone_cutter")
+    assert is_valid_identifier("terramap:path/is/allowed_slashes.png")
+    assert is_valid_identifier("weird.mod-id:both_are_allowed-dashes-and_underscores.and.dots")
+
+    assert not is_valid_identifier("")
+    assert not is_valid_identifier(" ")
+    assert not is_valid_identifier("minecraft:minecraft:stone")
+    assert not is_valid_identifier("minecraft:oak_stairs[facing=north]")
+    assert not is_valid_identifier("minecraft")