From da086952a10d30c7fbc46b3d1a6878fb6df7719e Mon Sep 17 00:00:00 2001
From: kclowes <kclowes@users.noreply.github.com>
Date: Wed, 13 Apr 2022 10:26:18 -0600
Subject: [PATCH 1/4] Add caching for sync chain_id

---
 web3/eth.py              | 19 ++-----------------
 web3/middleware/cache.py |  1 +
 2 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/web3/eth.py b/web3/eth.py
index 81cc271c6f..d3b23b5f04 100644
--- a/web3/eth.py
+++ b/web3/eth.py
@@ -114,7 +114,6 @@
 class BaseEth(Module):
     _default_account: Union[ChecksumAddress, Empty] = empty
     _default_block: BlockIdentifier = "latest"
-    _default_chain_id: Optional[int] = None
     gasPriceStrategy = None
 
     _gas_price: Method[Callable[[], Wei]] = Method(
@@ -358,14 +357,7 @@ async def block_number(self) -> BlockNumber:
 
     @property
     async def chain_id(self) -> int:
-        if self._default_chain_id is None:
-            return await self._chain_id()  # type: ignore
-        else:
-            return self._default_chain_id
-
-    @chain_id.setter
-    def chain_id(self, value: int) -> None:
-        self._default_chain_id = value
+        return await self._chain_id()  # type: ignore
 
     @property
     async def coinbase(self) -> ChecksumAddress:
@@ -637,14 +629,7 @@ def blockNumber(self) -> BlockNumber:
 
     @property
     def chain_id(self) -> int:
-        if self._default_chain_id is None:
-            return self._chain_id()
-        else:
-            return self._default_chain_id
-
-    @chain_id.setter
-    def chain_id(self, value: int) -> None:
-        self._default_chain_id = value
+        return self._chain_id()
 
     @property
     def chainId(self) -> int:
diff --git a/web3/middleware/cache.py b/web3/middleware/cache.py
index e81761b0a3..a47f4eb585 100644
--- a/web3/middleware/cache.py
+++ b/web3/middleware/cache.py
@@ -82,6 +82,7 @@
     # 'eth_getWork',
     # 'eth_submitWork',
     # 'eth_submitHashrate',
+    'eth_chainId',
 })
 
 

From 70ece1c67efcaa48e547a5ded49f1e1508af9966 Mon Sep 17 00:00:00 2001
From: kclowes <kclowes@users.noreply.github.com>
Date: Wed, 13 Apr 2022 11:48:06 -0600
Subject: [PATCH 2/4] Remove async chainId setter

Will add async chainId to the cache once the simple_cache_middleware is available on async
---
 tests/core/eth-module/test_eth_properties.py | 39 --------------------
 1 file changed, 39 deletions(-)

diff --git a/tests/core/eth-module/test_eth_properties.py b/tests/core/eth-module/test_eth_properties.py
index 813af404e8..f782061f65 100644
--- a/tests/core/eth-module/test_eth_properties.py
+++ b/tests/core/eth-module/test_eth_properties.py
@@ -1,23 +1,5 @@
 import pytest
 
-from web3 import Web3
-from web3.eth import (
-    AsyncEth,
-)
-from web3.providers.eth_tester.main import (
-    AsyncEthereumTesterProvider,
-)
-
-
-@pytest.fixture
-def async_w3():
-    return Web3(
-        AsyncEthereumTesterProvider(),
-        middlewares=[],
-        modules={
-            'eth': (AsyncEth,),
-        })
-
 
 def test_eth_protocol_version(web3):
     with pytest.warns(DeprecationWarning):
@@ -36,24 +18,3 @@ def test_eth_chain_id(web3):
 def test_eth_chainId(web3):
     with pytest.warns(DeprecationWarning):
         assert web3.eth.chainId == 61
-
-
-def test_set_chain_id(web3):
-    assert web3.eth.chain_id == 61
-
-    web3.eth.chain_id = 72
-    assert web3.eth.chain_id == 72
-
-    web3.eth.chain_id = None
-    assert web3.eth.chain_id == 61
-
-
-@pytest.mark.asyncio
-async def test_async_set_chain_id(async_w3):
-    assert await async_w3.eth.chain_id == 61
-
-    async_w3.eth.chain_id = 72
-    assert await async_w3.eth.chain_id == 72
-
-    async_w3.eth.chain_id = None
-    assert await async_w3.eth.chain_id == 61

From e1f41981193cd8feb3f3a75ee14fc5e117b751a4 Mon Sep 17 00:00:00 2001
From: kclowes <kclowes@users.noreply.github.com>
Date: Wed, 13 Apr 2022 12:05:48 -0600
Subject: [PATCH 3/4] Add docs

---
 docs/web3.eth.rst | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/docs/web3.eth.rst b/docs/web3.eth.rst
index eaa1653782..7d5a473772 100644
--- a/docs/web3.eth.rst
+++ b/docs/web3.eth.rst
@@ -216,6 +216,18 @@ The following properties are available on the ``web3.eth`` namespace.
        >>> web3.eth.chain_id
        61
 
+   .. note::
+
+      This property gets called frequently in validation middleware,
+      but `chain_id` is added to the ``simple_cache_middleware`` by default.
+      Add the :meth:`simple_cache_middleware<web3.middleware.construct_simple_cache_middleware>`
+      to the ``middleware_onion`` to increase performance:
+
+       .. code-block:: python
+
+          >>> from web3.middleware import simple_cache_middleware
+          >>> w3.middleware_onion.add(simple_cache_middleare)
+
 
 .. py:attribute:: Eth.chainId
 

From dc22af8cde3e8edf1974b669dfd66f24a899d191 Mon Sep 17 00:00:00 2001
From: kclowes <kclowes@users.noreply.github.com>
Date: Wed, 13 Apr 2022 12:15:25 -0600
Subject: [PATCH 4/4] Add newsfragment for simple_cache_middleware, take out
 old, confusing newsfragment

---
 newsfragments/2207.feature.rst | 1 -
 newsfragments/2425.feature.rst | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)
 delete mode 100644 newsfragments/2207.feature.rst
 create mode 100644 newsfragments/2425.feature.rst

diff --git a/newsfragments/2207.feature.rst b/newsfragments/2207.feature.rst
deleted file mode 100644
index 78a6f8bbd5..0000000000
--- a/newsfragments/2207.feature.rst
+++ /dev/null
@@ -1 +0,0 @@
-Add setter for the Eth.chain_id property
diff --git a/newsfragments/2425.feature.rst b/newsfragments/2425.feature.rst
new file mode 100644
index 0000000000..fc01c0dcdc
--- /dev/null
+++ b/newsfragments/2425.feature.rst
@@ -0,0 +1 @@
+Add sync chain_id to ``simple_middleware_cache``