Added test snapshot and updated coverage

jest.config.js

@@ -1,8 +1,12 @@
 module.exports = {
+    rootDir: './src',
     collectCoverage: true,
     testURL: 'http://localhost',
 
     modulePathIgnorePatterns: [
         'node_modules',
     ],
+    collectCoverageFrom: [
+        'js/utils/**.js',
+    ],
 };

src/js/utils/__tests__/__snapshots__/ethUtils.test.js.snap

@@ -1,3 +1,11 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`sds decimalToHex 1`] = `2`;
+exports[`eth utils decimalToHex 1`] = `"0"`;
+
+exports[`eth utils decimalToHex 2`] = `"1"`;
+
+exports[`eth utils decimalToHex 3`] = `"2"`;
+
+exports[`eth utils decimalToHex 4`] = `"64"`;
+
+exports[`eth utils decimalToHex 5`] = `"3e7"`;

src/js/utils/__tests__/ethUtils.test.js

@@ -1,5 +1,11 @@
-describe('sds', () => {
+import * as ethUtils from '../ethUtils';
+
+describe('eth utils', () => {
     it('decimalToHex', () => {
-        expect(2).toMatchSnapshot();
+        const input = [0, 1, 2, 100, 999];
+
+        input.forEach((entry) => {
+            expect(ethUtils.decimalToHex(entry)).toMatchSnapshot();
+        });
     });
 });