From bb3c21cab2208eddd9bcc56339e07b7e89b5f7ed Mon Sep 17 00:00:00 2001
From: Samuel Furter <sam@tokenate.io>
Date: Mon, 18 Feb 2019 17:40:08 +0100
Subject: [PATCH] eth_chainId method implemented

---
 .../src/methods/network/ChainIdMethod.js      | 48 +++++++++++++++++++
 .../src/methods/network/ChainIdMethodTest.js  | 37 ++++++++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 packages/web3-core-method/src/methods/network/ChainIdMethod.js
 create mode 100644 packages/web3-core-method/tests/src/methods/network/ChainIdMethodTest.js

diff --git a/packages/web3-core-method/src/methods/network/ChainIdMethod.js b/packages/web3-core-method/src/methods/network/ChainIdMethod.js
new file mode 100644
index 00000000000..d2a972defbe
--- /dev/null
+++ b/packages/web3-core-method/src/methods/network/ChainIdMethod.js
@@ -0,0 +1,48 @@
+/*
+    This file is part of web3.js.
+
+    web3.js is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    web3.js is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with web3.js.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @file ListeningMethod.js
+ * @author Samuel Furter <samuel@ethereum.org>
+ * @date 2018
+ */
+
+import AbstractCallMethod from '../../../lib/methods/AbstractCallMethod';
+
+export default class ChainIdMethod extends AbstractCallMethod {
+    /**
+     * @param {Utils} utils
+     * @param {Object} formatters
+     *
+     * @constructor
+     */
+    constructor(utils, formatters) {
+        super('eth_chainId', 0, utils, formatters);
+    }
+
+    /**
+     * This method will be executed after the RPC request.
+     *
+     * @method afterExecution
+     *
+     * @param {Object} response
+     *
+     * @returns {Number}
+     */
+    afterExecution(response) {
+        return this.utils.hexToNumber(response);
+    }
+}
diff --git a/packages/web3-core-method/tests/src/methods/network/ChainIdMethodTest.js b/packages/web3-core-method/tests/src/methods/network/ChainIdMethodTest.js
new file mode 100644
index 00000000000..8787b47c36b
--- /dev/null
+++ b/packages/web3-core-method/tests/src/methods/network/ChainIdMethodTest.js
@@ -0,0 +1,37 @@
+import * as Utils from 'web3-utils';
+import AbstractCallMethod from '../../../../lib/methods/AbstractCallMethod';
+import ChainIdMethod from '../../../../src/methods/network/ChainIdMethod';
+
+// Mocks
+jest.mock('Utils');
+
+/**
+ * PeerCountMethod test
+ */
+describe('PeerCountMethodTest', () => {
+    let method;
+
+    beforeEach(() => {
+        method = new ChainIdMethod(Utils, null);
+    });
+
+    it('constructor check', () => {
+        expect(method).toBeInstanceOf(AbstractCallMethod);
+
+        expect(method.rpcMethod).toEqual('eth_chainId');
+
+        expect(method.parametersAmount).toEqual(0);
+
+        expect(method.utils).toEqual(Utils);
+
+        expect(method.formatters).toEqual(null);
+    });
+
+    it('afterExecution should map the response', () => {
+        Utils.hexToNumber.mockReturnValueOnce(61);
+
+        expect(method.afterExecution('0x0')).toEqual(61);
+
+        expect(Utils.hexToNumber).toHaveBeenCalledWith('0x0');
+    });
+});