added another test for ecma option

package.json

@@ -11,7 +11,7 @@
   ],
   "scripts": {
     "start": "npm run build -- -w",
-    "build": "cross-env NODE_ENV=production babel src -d dist --ignore 'src/**/*.test.js",
+    "build": "cross-env NODE_ENV=production babel src -d dist --ignore 'src/**/*.test.js'",
     "test:all": "npm run test:coverage && npm run test:lint",
     "test": "jest",
     "test:coverage": "jest --collectCoverageFrom='src/**/*.js' --coverage",

src/index.js

@@ -7,9 +7,9 @@ import { SourceMapConsumer } from 'source-map';
 import { SourceMapSource, RawSource, ConcatSource } from 'webpack-sources';
 import RequestShortener from 'webpack/lib/RequestShortener';
 import ModuleFilenameHelpers from 'webpack/lib/ModuleFilenameHelpers';
-import Uglify from './uglify';
 import validateOptions from 'schema-utils';
 import schema from '../options.json';
+import Uglify from './uglify';
 
 /* eslint-disable
   no-param-reassign
@@ -21,7 +21,7 @@ class UglifyJsPlugin {
   constructor(options = {}) {
     validateOptions(schema, options, 'UglifyJs Plugin');
 
-    const = {
+    const {
       uglifyOptions = {},
       test = /\.js$/i,
       warningsFilter = () => true,

test/invalid-options.test.js

@@ -54,6 +54,10 @@ describe('when applied with invalid options', () => {
       new UglifyJsPlugin({ uglifyOptions: { emca: 8 } });
     }).not.toThrow();
 
+    expect(() => {
+      new UglifyJsPlugin({ uglifyOptions: { ecma: 7.5 } });
+    }).toThrow('should be integer');
+
     expect(() => {
       new UglifyJsPlugin({ uglifyOptions: { ecma: true } });
     }).toThrow('should be integer');