From c7ad27ec06384934a3e8089dfcc765c3f158b64c Mon Sep 17 00:00:00 2001
From: David Murdoch <david@davidmurdoch.com>
Date: Fri, 11 Sep 2020 12:51:14 -0400
Subject: [PATCH 1/3] add test for customized `eth_chainId` RPC value via
 `_chainIdRpc` option

---
 test/contracts/chainId/ChainId.sol | 11 +++++++
 test/local/chainId.js              | 52 ++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 test/contracts/chainId/ChainId.sol
 create mode 100644 test/local/chainId.js

diff --git a/test/contracts/chainId/ChainId.sol b/test/contracts/chainId/ChainId.sol
new file mode 100644
index 0000000000..195b87c3c6
--- /dev/null
+++ b/test/contracts/chainId/ChainId.sol
@@ -0,0 +1,11 @@
+pragma solidity ^0.6.0;
+
+contract ChainId {
+  function getChainId() pure external returns (uint256) {
+    uint256 id;
+    assembly {
+      id := chainid()
+    }
+    return id;
+  }
+}
diff --git a/test/local/chainId.js b/test/local/chainId.js
new file mode 100644
index 0000000000..e49f43507b
--- /dev/null
+++ b/test/local/chainId.js
@@ -0,0 +1,52 @@
+const assert = require("assert");
+const initializeTestProvider = require("../helpers/web3/initializeTestProvider");
+const { compile } = require("../helpers/contract/compileAndDeploy");
+
+describe.only("Chain Id option", function() {
+  const contract = {};
+
+  before("compile contract", async function() {
+    this.timeout(10000);
+    const contractSubdirectory = "chainId";
+    const contractFilename = "ChainId";
+    const subcontractFiles = [];
+    const { abi, bytecode } = await compile(contractFilename, subcontractFiles, contractSubdirectory, "istanbul");
+    contract.abi = abi;
+    contract.bytecode = bytecode;
+  });
+
+  describe("Allow Unlimited Contract Size", function() {
+    let context;
+
+    before("Setup provider to allow unlimited contract size", async function() {
+      const ganacheOptions = {
+        _chainId: 1,
+        _chainIdRpc: 1
+      };
+
+      context = await initializeTestProvider(ganacheOptions);
+    });
+
+    before("deploy contract", async function() {
+      const chainIdContract = new context.web3.eth.Contract(contract.abi);
+      contract.deployed = await chainIdContract
+        .deploy({
+          data: contract.bytecode
+        })
+        .send({
+          from: context.accounts[0],
+          gas: 3141592
+        });
+    });
+
+    it("chainid opcode should match options", async function() {
+      const chainId = await contract.deployed.methods.getChainId().call();
+      assert.strictEqual(chainId, "1");
+    });
+
+    it("chain id rpc should match options", async function() {
+      const chainId = await context.web3.eth.getChainId();
+      assert.strictEqual(chainId, 1);
+    });
+  });
+});

From afb14b17757e349d8c20503db1c558e5c37e9905 Mon Sep 17 00:00:00 2001
From: David Murdoch <david@davidmurdoch.com>
Date: Fri, 11 Sep 2020 12:51:51 -0400
Subject: [PATCH 2/3] add temp option to customize `eth_chainId` RPC value

---
 lib/provider.js                     | 1 +
 lib/subproviders/geth_api_double.js | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/provider.js b/lib/provider.js
index 66423e18e3..05882b9302 100644
--- a/lib/provider.js
+++ b/lib/provider.js
@@ -54,6 +54,7 @@ function Provider(options) {
 
 const defaultOptions = {
   _chainId: 1,
+  _chainIdRpc: 1337,
   vmErrorsOnRPCResponse: true,
   verbose: false,
   asyncRequestProcessing: false,
diff --git a/lib/subproviders/geth_api_double.js b/lib/subproviders/geth_api_double.js
index 1e4dfb3f3e..936cd8ba36 100644
--- a/lib/subproviders/geth_api_double.js
+++ b/lib/subproviders/geth_api_double.js
@@ -149,7 +149,7 @@ GethApiDouble.prototype.eth_blockNumber = function(callback) {
 };
 
 GethApiDouble.prototype.eth_chainId = function(callback) {
-  callback(null, to.hex(1337));
+  callback(null, to.hex(this.options._chainIdRpc));
 };
 
 GethApiDouble.prototype.eth_coinbase = function(callback) {

From e9c100cb723b496fb49abd47917a9368a1f65d00 Mon Sep 17 00:00:00 2001
From: David Murdoch <david@davidmurdoch.com>
Date: Fri, 11 Sep 2020 12:56:29 -0400
Subject: [PATCH 3/3] add `_chainId` and `_chainIdRpc` options to README

---
 README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/README.md b/README.md
index 18455bc5fd..44c0fadaac 100644
--- a/README.md
+++ b/README.md
@@ -84,6 +84,8 @@ Both `.provider()` and `.server()` take a single object which allows you to spec
 * `"fork_block_number"`: `string` or `number` - Block number the provider should fork from, when the `fork` option is specified. If the `fork` option is specified as a string including the `@` sign and a block number, the block number in the `fork` parameter takes precedence.
 - `"forkCacheSize"`: `number` - The maximum size, in bytes, of the in-memory cache for queries on a chain fork. Defaults to `1_073_741_824` bytes (1 gigabyte). You can set this to `0` to disable caching (not recommended), or to `-1` for unlimited (will be limited by your node/browser process).
 * `"network_id"`: Specify the network id ganache-core will use to identify itself (defaults to the current time or the network id of the forked blockchain if configured)
+* `"_chainId"`: **(temporary option until v3)** Specify the chain's chainId. For legacy reasons, this does NOT affect the `eth_chainId` RPC response! Defaults to `1`
+* `"_chainIdRpc"`: **(temporary option until v3)** Specify the `eth_chainId` RPC response value. For legacy reasons, this does NOT affect the chain's `chainid`! Defaults to `1337`
 * `"time"`: `Date` - Date that the first block should start. Use this feature, along with the `evm_increaseTime` method to test time-dependent code.
 * `"locked"`: `boolean` - whether or not accounts are locked by default.
 * `"unlocked_accounts"`: `Array` - array of addresses or address indexes specifying which accounts should be unlocked.