From a1e9efe849a3cb22912b8912de75f0f6a81b7568 Mon Sep 17 00:00:00 2001
From: Vinay Pulim <v@pulim.com>
Date: Wed, 22 Aug 2018 00:29:21 -0400
Subject: [PATCH] Added support for private network parameters

---
 docs/index.md      |  3 ++-
 index.js           | 13 ++++++++--
 tests/chains.js    | 21 ++++++++++++++++
 tests/testnet.json | 63 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 97 insertions(+), 3 deletions(-)
 create mode 100644 tests/testnet.json

diff --git a/docs/index.md b/docs/index.md
index ff3a823..f8385bc 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -45,7 +45,8 @@ Sets the chain
 
 **Parameters**
 
--   `chain` **([String][27] \| [Number][28])** String ('mainnet') or Number (1) chain representation
+-   `chain` **([String][27] \| [Number][28] | Dictionary)** String ('mainnet') or Number (1) chain
+        representation. Or, a Dictionary of chain parameters for a private network.
 
 ### setHardfork
 
diff --git a/index.js b/index.js
index c5b7509..4bc8282 100644
--- a/index.js
+++ b/index.js
@@ -22,7 +22,8 @@ class Common {
 
   /**
    * Sets the chain
-   * @param {String|Number} chain String ('mainnet') or Number (1) chain representation
+   * @param {String|Number|Dictionary} chain String ('mainnet') or Number (1) chain
+   *     representation. Or, a Dictionary of chain parameters for a private network.
    */
   setChain (chain) {
     if (typeof (chain) === 'number') {
@@ -37,6 +38,14 @@ class Common {
       } else {
         throw new Error(`Chain with name ${chain} not supported`)
       }
+    } else if (typeof (chain) === 'object') {
+      const required = ['networkId', 'genesis', 'hardforks', 'bootstrapNodes']
+      for (let param of required) {
+        if (chain[param] === undefined) {
+          throw new Error(`Missing required chain parameter: ${param}`)
+        }
+      }
+      this._chainParams = chain
     } else {
       throw new Error('Wrong input format')
     }
@@ -362,7 +371,7 @@ class Common {
    * @returns {String} chain name (lower case)
    */
   chainName () {
-    return chainParams['names'][this.chainId()]
+    return chainParams['names'][this.chainId()] || this._chainParams['name']
   }
 
   /**
diff --git a/tests/chains.js b/tests/chains.js
index d35ffc6..59bc9e7 100644
--- a/tests/chains.js
+++ b/tests/chains.js
@@ -60,4 +60,25 @@ tape('[Common]: Initialization / Chain params', function (t) {
 
     st.end()
   })
+
+  t.test('Should provide correct access to private network chain parameters', function (st) {
+    let chainParams = require('./testnet.json')
+    let c = new Common(chainParams, 'byzantium')
+    st.equal(c.chainName(), 'testnet', 'should initialize with chain name')
+    st.equal(c.chainId(), 12345, 'should return correct chain Id')
+    st.equal(c.networkId(), 12345, 'should return correct network Id')
+    st.equal(c.genesis().hash, '0xaa00000000000000000000000000000000000000000000000000000000000000', 'should return correct genesis hash')
+    st.equal(c.hardforks()[3]['block'], 3, 'should return correct hardfork data')
+    st.equal(c.bootstrapNodes()[1].ip, '10.0.0.2', 'should return a bootstrap node array')
+
+    st.end()
+  })
+
+  t.test('Should handle custom chain parameters with missing field', function (st) {
+    let chainParams = require('./testnet.json')
+    delete chainParams['hardforks']
+    st.throws(function () { new Common(chainParams) }, /Missing required/, 'should throw an exception on missing parameter') // eslint-disable-line no-new
+
+    st.end()
+  })
 })
diff --git a/tests/testnet.json b/tests/testnet.json
new file mode 100644
index 0000000..84b8f99
--- /dev/null
+++ b/tests/testnet.json
@@ -0,0 +1,63 @@
+{
+  "name": "testnet",
+  "chainId": 12345,
+  "networkId": 12345,
+  "comment": "Private test network",
+  "genesis": {
+    "hash": "0xaa00000000000000000000000000000000000000000000000000000000000000",
+    "timestamp": null,
+    "gasLimit": 1000000,
+    "difficulty": 1,
+    "nonce": "0xbb00000000000000",
+    "extraData": "0xcc000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    "stateRoot": "0xdd00000000000000000000000000000000000000000000000000000000000000"
+  },
+  "hardforks": [
+    {
+      "name": "chainstart",
+      "block": 0,
+      "consensus": "poa",
+      "finality": null
+    },
+    {
+      "name": "homestead",
+      "block": 1,
+      "consensus": "poa",
+      "finality": null
+    },
+    {
+      "name": "tangerineWhistle",
+      "block": 2,
+      "consensus": "poa",
+      "finality": null
+    },
+    {
+      "name": "spuriousDragon",
+      "block": 3,
+      "consensus": "poa",
+      "finality": null
+    },
+    {
+      "name": "byzantium",
+      "block": 4,
+      "consensus": "poa",
+      "finality": null
+    }
+  ],
+  "bootstrapNodes": [
+    {
+      "ip": "10.0.0.1",
+      "port": 30303,
+      "id": "11000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+      "location": "",
+      "comment": ""
+    },
+    {
+      "ip": "10.0.0.2",
+      "port": 30303,
+      "id": "22000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+      "location": "",
+      "comment": ""
+    }
+  ]
+}