Cannot generate routes with classic decorator

I am trying to generate a route `ember g route location/account/add` and I am getting errors and only the template and template.js gets generated.

```
ERROR Summary:
- stack: Error: Line 5: Unexpected token ILLEGAL
at ErrorHandler.constructError (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:3396:22)
at ErrorHandler.createError (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:3414:27)
at ErrorHandler.throwError (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:3422:21)
at Scanner.throwUnexpectedToken (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:3505:28)
at Scanner.scanPunctuator (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:4026:19)
at Scanner.lex (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:4628:22)
at JSXParser.Parser.nextToken (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:634:30)
at JSXParser.Parser.consumeSemicolon (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:841:19)
at JSXParser.Parser.parseImportDeclaration (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:3180:15)
at JSXParser.Parser.parseStatementListItem (/Users/john/Development/my-app/node_modules/ember-router-generator/node_modules/esprima/dist/esprima.js:1803:39)
```


```js
import classic from 'ember-classic-decorator';
import EmberRouter from '@ember/routing/router';
import config from './config/environment';

@classic
class Router extends EmberRouter {
location = config.locationType;
rootURL = config.rootURL;

didTransition() {
super.didTransition(...arguments);

if (window.ga && typeof window.ga === 'function') {
// my code
}
}
}

Router.map(function() {});

export default Router
```

---

Output from `ember version --verbose && npm --version && yarn --version`:
```
Browserslist: caniuse-lite is outdated. Please run next command `yarn upgrade`
ember-cli: 3.12.0
http_parser: 2.9.3
node: 10.20.1
v8: 6.8.275.32-node.56
uv: 1.34.2
zlib: 1.2.11
brotli: 1.0.7
ares: 1.15.0
modules: 64
nghttp2: 1.39.2
napi: 6
openssl: 1.1.1e
icu: 64.2
unicode: 12.1
cldr: 35.1
tz: 2019c
os: darwin x64
6.14.4
1.22.4
```

Ember version is 3.12 as well