Chain ID

tests/parser/syntax/test_chainid.py

@@ -0,0 +1,99 @@
+import pytest
+from pytest import (
+    raises,
+)
+
+from vyper import (
+    compiler,
+)
+from vyper.exceptions import (
+    TypeMismatchException,
+)
+
+fail_list = [
+    """
+@public
+def foo() -> int128[2]:
+    return [3,chain.id]
+    """,
+    """
+@public
+def foo() -> decimal(wei / sec):
+    x: int128(wei) = as_wei_value(5, "finney")
+    y: int128 = chain.id + 50
+    return x / y
+    """,
+    """
+@public
+def foo():
+    x: bytes[10] = slice("cow", start=0, len=chain.id)
+    """,
+    """
+@public
+def foo():
+    x: int128 = 7
+    y: int128 = min(x, chain.id)
+    """,
+    """
+a: map(timestamp, int128)
+
+@public
+def add_record():
+    self.a[chain.id] = chain.id + 20
+    """,
+    """
+a: map(int128, timestamp)
+
+@public
+def add_record():
+    self.a[chain.id] = chain.id + 20
+    """,
+    """
+@public
+def foo(inp: bytes[10]) -> bytes[3]:
+    return slice(inp, start=chain.id, len=3)
+    """,
+]
+
+
+@pytest.mark.parametrize('bad_code', fail_list)
+def test_chain_fail(bad_code):
+
+    if isinstance(bad_code, tuple):
+        with raises(bad_code[1]):
+            compiler.compile_code(bad_code[0])
+    else:
+        with raises(TypeMismatchException):
+            compiler.compile_code(bad_code)
+
+
+valid_list = [
+    """
+@public
+@constant
+def get_chain_id() -> uint256:
+    return chain.id
+    """,
+    """
+@public
+@constant
+def check_chain_id(c: uint256) -> bool:
+    return chain.id == c
+    """,
+]
+
+
+@pytest.mark.parametrize('good_code', valid_list)
+def test_chain_success(good_code):
+    assert compiler.compile_code(good_code) is not None
+
+
+def test_chainid_operation(get_contract_with_gas_estimation):
+    code = """
+@public
+@constant
+def get_chain_id() -> uint256:
+    return chain.id
+    """
+    c = get_contract_with_gas_estimation(code)
+    assert c.get_chain_id() == 0  # Default value of py-evm

vyper/opcodes.py

@@ -48,6 +48,7 @@
     'NUMBER': [0x43, 0, 1, 2],
     'DIFFICULTY': [0x44, 0, 1, 2],
     'GASLIMIT': [0x45, 0, 1, 2],
+    'CHAINID': [0x46, 0, 1, 2],
     'POP': [0x50, 1, 0, 2],
     'MLOAD': [0x51, 1, 1, 3],
     'MSTORE': [0x52, 2, 0, 3],

vyper/parser/expr.py

@@ -69,6 +69,7 @@
     "block",
     "msg",
     "tx",
+    "chain",
 }
 
 
@@ -380,6 +381,8 @@ def attribute(self):
                 )
             elif key == "tx.origin":
                 return LLLnode.from_list(['origin'], typ='address', pos=getpos(self.expr))
+            elif key == "chain.id":
+                return LLLnode.from_list(['chainid'], typ='uint256', pos=getpos(self.expr))
             else:
                 raise ParserException("Unsupported keyword: " + key, self.expr)
         # Other variables

vyper/utils.py

@@ -172,7 +172,7 @@ def in_bounds(cls, type_str, value):
     '_init_', '___init___', '____init____',
     '_default_', '___default___', '____default____',
     # environment variables
-    'block', 'msg', 'tx',
+    'block', 'msg', 'tx', 'chain', 'chainid',
     'blockhash', 'timestamp', 'timedelta',
     # boolean literals
     'true', 'false',