feat: add selector to constructor ABI (#54)

ethpm_types/abi.py

@@ -143,6 +143,14 @@ def signature(self) -> str:
         input_args = ", ".join(i.signature for i in self.inputs)
         return f"constructor({input_args})"
 
+    def selector(self) -> str:
+        """
+        String representing the constructor selector.
+        """
+
+        input_names = ",".join(i.canonical_type for i in self.inputs)
+        return f"constructor({input_names})"
+
 
 class FallbackABI(BaseModel):
     """

tests/test_abi.py

@@ -0,0 +1,9 @@
+from ethpm_types.abi import ABIType, ConstructorABI
+
+
+def test_constructor_selector():
+    constructor = ConstructorABI(
+        type="constructor",
+        inputs=[ABIType(name="contract_address", type="address", internalType="address")],
+    )
+    assert constructor.selector() == "constructor(address)"