Disable forking network env

README.md

@@ -168,7 +168,7 @@ Note that in `eval()` mode, titanoboa uses slightly different optimization setti
 ### Forking
 Create a fork of mainnet given rpc.
 ```python
-In [1]: import boa; boa.env.fork(url="<rpc server address>")
+In [1]: import boa; boa.fork(url="<rpc server address>")
 
 In [2]: %load_ext boa.ipython
 
@@ -189,7 +189,7 @@ Out[5]: 'Curve DAO Token'
 
 Cast current deployed addresses to vyper contract
 ```python
->>> import boa; boa.env.fork(url="<rpc server address>")
+>>> import boa; boa.fork(url="<rpc server address>")
 >>> c = boa.load_partial("examples/ERC20.vy").at("0xD533a949740bb3306d119CC777fa900bA034cd52")
 >>> c.name()
     'Curve DAO Token'

boa/__init__.py

@@ -1,5 +1,6 @@
 import contextlib
 import sys
+from typing import Union
 
 from boa.contracts.base_evm_contract import BoaError
 from boa.contracts.vyper.vyper_contract import check_boa_error_matches
@@ -45,19 +46,49 @@ def set_env(new_env):
     Env._singleton = new_env
 
 
-def set_browser_env(address=None):
+def set_browser_env(address=None, chain_id: Union[None, str, int] = None):
     """Set the environment to use the browser's network in Jupyter/Colab"""
     # import locally because jupyter is generally not installed
-    from boa.integrations.jupyter import BrowserEnv
+    from boa.integrations.jupyter.browser import BrowserRPC, BrowserSigner
 
-    set_env(BrowserEnv(address))
+    rpc = BrowserRPC(chain_id)
+    e = NetworkEnv(rpc)
+    signer = BrowserSigner(address, rpc)
+    setattr(e, "signer", signer)
+    e.set_eoa(signer)
+    return set_env(e)
 
 
 def set_network_env(url):
     """Set the environment to use a custom network URL"""
     set_env(NetworkEnv.from_url(url))
 
 
+def fork(*args, try_prefetch_state=False, fast_mode_enabled=False, **kwargs):
+    """Fork the current environment to use a custom network URL"""
+    e = Env(try_prefetch_state, fast_mode_enabled)
+    e.fork(*args, **kwargs)
+    return set_env(e)
+
+
+def fork_browser(
+    url: str,
+    address=None,
+    *args,
+    chain_id: Union[None, str, int] = None,
+    try_prefetch_state=False,
+    fast_mode_enabled=False,
+    **kwargs,
+):
+    """Fork the current environment to use browser RPC"""
+    from boa.integrations.jupyter import BrowserRPC, BrowserSigner
+
+    rpc = BrowserRPC(url)
+    e = Env(try_prefetch_state, fast_mode_enabled)
+    e.fork_rpc(rpc, *args, **kwargs)
+    return set_env(e)
+
+
 def reset_env():
     set_env(Env())
 

boa/integrations/jupyter/__init__.py

@@ -1,4 +1,4 @@
-from boa.integrations.jupyter.browser import BrowserEnv, BrowserRPC, BrowserSigner
+from boa.integrations.jupyter.browser import BrowserRPC, BrowserSigner
 from boa.integrations.jupyter.constants import PLUGIN_NAME
 from boa.integrations.jupyter.handlers import setup_handlers
 
@@ -19,7 +19,6 @@ def load_jupyter_server_extension(server_app):
 __all__ = [  # type: ignore
     BrowserSigner,
     BrowserRPC,
-    BrowserEnv,
     load_jupyter_server_extension,
     _load_jupyter_server_extension,
 ]

boa/integrations/jupyter/browser.py

@@ -10,7 +10,7 @@
 from multiprocessing.shared_memory import SharedMemory
 from os import urandom
 from os.path import dirname, join, realpath
-from typing import Any
+from typing import Any, Union
 
 import nest_asyncio
 from IPython.display import Javascript, display
@@ -24,7 +24,6 @@
     SHARED_MEMORY_LENGTH,
     TRANSACTION_TIMEOUT_MESSAGE,
 )
-from boa.network import NetworkEnv
 from boa.rpc import RPC, RPCError
 from boa.util.abi import Address
 
@@ -57,7 +56,9 @@ class BrowserRPC(RPC):
 
     _debug_mode = False
 
-    def __init__(self):
+    def __init__(self, chain_id: Union[None, str, int] = None):
+        if chain_id is not None:
+            self.set_chain_id(chain_id)
         if not colab_eval_js:
             # colab creates a new iframe for every call, we need to re-inject it every time
             # for jupyterlab we only need to do it once
@@ -93,6 +94,12 @@ def wait_for_tx_receipt(self, tx_hash, timeout: float, poll_latency=1):
             timeout_message=RPC_TIMEOUT_MESSAGE,
         )
 
+    def set_chain_id(self, chain_id: int | str):
+        return self.fetch(
+            "wallet_switchEthereumChain",
+            [{"chainId": chain_id if isinstance(chain_id, str) else hex(chain_id)}],
+        )
+
 
 class BrowserSigner:
     """
@@ -144,26 +151,6 @@ def sign_typed_data(self, full_message: dict[str, Any]) -> str:
         )
 
 
-class BrowserEnv(NetworkEnv):
-    """
-    A NetworkEnv object that uses the BrowserSigner and BrowserRPC classes.
-    """
-
-    _rpc = BrowserRPC()  # Browser is always global anyway, we can make it static
-
-    def __init__(self, address=None, **kwargs):
-        super().__init__(self._rpc, **kwargs)
-        self.signer = BrowserSigner(address, self._rpc)
-        self.set_eoa(self.signer)
-
-    def set_chain_id(self, chain_id: int | str):
-        self._rpc.fetch(
-            "wallet_switchEthereumChain",
-            [{"chainId": chain_id if isinstance(chain_id, str) else hex(chain_id)}],
-        )
-        self._reset_fork()
-
-
 def _javascript_call(js_func: str, *args, timeout_message: str) -> Any:
     """
     This function attempts to call a Javascript function in the browser and then

boa/network.py

@@ -460,10 +460,13 @@ def _debug_tt(self, tx_hash):
     def _get_nonce(self, addr):
         return self._rpc.fetch("eth_getTransactionCount", [addr, "latest"])
 
+    def fork_rpc(self, rpc: RPC, reset_traces=True, block_identifier="safe", **kwargs):
+        raise TypeError("cannot fork a network env")
+
     def _reset_fork(self, block_identifier="latest"):
         # use "latest" to make sure we are forking with up-to-date state
         # but use reset_traces=False to help with storage dumps
-        self.fork_rpc(
+        super().fork_rpc(
             self._rpc,
             reset_traces=False,
             block_identifier=block_identifier,

docs/source/api.rst

@@ -162,7 +162,7 @@ High-Level Functionality
     .. code-block:: python
 
         >>> import boa, os
-        >>> boa.env.fork(os.environ["ALCHEMY_MAINNET_ENDPOINT"])
+        >>> boa.fork(os.environ["ALCHEMY_MAINNET_ENDPOINT"])
         >>> crvusd = boa.from_etherscan("0xf939E0A03FB07F59A73314E73794Be0E57ac1b4E", name="crvUSD")
         >>> crvusd
         <crvUSD interface at 0xf939E0A03FB07F59A73314E73794Be0E57ac1b4E>
@@ -467,7 +467,7 @@ Low-Level Functionality
             >>> import boa
             >>> boa.env.vm.state.block_number
             1
-            >>> boa.env.fork("https://rpc.ankr.com/eth")
+            >>> boa.fork("https://rpc.ankr.com/eth")
             >>> boa.env.vm.state.block_number
             16038471
 

tests/integration/fork/conftest.py

@@ -17,5 +17,5 @@ def rpc_url():
 def forked_env(rpc_url):
     with boa.swap_env(Env()):
         block_id = 18801970  # some block we know the state of
-        boa.env.fork(rpc_url, block_identifier=block_id)
+        boa.fork(rpc_url, block_identifier=block_id)
         yield

tests/unitary/jupyter/test_browser.py

@@ -226,8 +226,8 @@ def test_browser_chain_id(token, env, display_mock, mock_callback):
     mock_callback("eth_chainId", "0x1234")
     assert env.get_chain_id() == 4660
     mock_callback("wallet_switchEthereumChain")
-    env.set_chain_id(1)
-    assert display_mock.call_count == 4
+    env._rpc.set_chain_id(1)
+    assert display_mock.call_count == 2
     (js,), _ = display_mock.call_args_list[1]
     assert (
         f'rpc("{token}", "wallet_switchEthereumChain", [{{"chainId": "0x1"}}])'