angular2 failing lodash import

3
votes

I started simple Angular 2 app, all working. But when I add import of lodash and try to use it, I get errors and the app stops working, and can't figure out what is the problem.

I am getting these 2 errors in console:

Uncaught SyntaxError: Unexpected token <__exec @ system.src.js:1374entry.execute @ system.src.js:3300linkDynamicModule @ system.src.js:2921link @ system.src.js:2764execute @ system.src.js:3096doDynamicExecute @ system.src.js:715link @ system.src.js:908doLink @ system.src.js:569updateLinkSetOnLoad @ system.src.js:617(anonymous function) @ system.src.js:430run @ angular2-polyfills.js:138zoneBoundFn @ angular2-polyfills.js:111lib$es6$promise$$internal$$tryCatch @ angular2-polyfills.js:1511lib$es6$promise$$internal$$invokeCallback @ angular2-polyfills.js:1523lib$es6$promise$$internal$$publish @ angular2-polyfills.js:1494(anonymous function) @ angular2-polyfills.js:243run @ angular2-polyfills.js:138zoneBoundFn @ angular2-polyfills.js:111lib$es6$promise$asap$$flush @ angular2-polyfills.js:1305 angular2-polyfills.js:138

Uncaught SyntaxError: Unexpected token < Evaluating http://localhost:3000/lodash Error loading http://localhost:3000/app/app.jsrun @ angular2-polyfills.js:138zoneBoundFn @ angular2-polyfills.js:111lib$es6$promise$$internal$$tryCatch @ angular2-polyfills.js:1511lib$es6$promise$$internal$$invokeCallback @ angular2-polyfills.js:1523lib$es6$promise$$internal$$publish @ angular2-polyfills.js:1494lib$es6$promise$$internal$$publishRejection @ angular2-polyfills.js:1444(anonymous function) @ angular2-polyfills.js:243run @ angular2-polyfills.js:138zoneBoundFn @ angular2-polyfills.js:111lib$es6$promise$asap$$flush @ angular2-polyfills.js:1305

FILES

index.html

<html>

  <head>
    <title>Angular 2 QuickStart</title>

    <!-- 1. Load libraries -->
    <!-- IE required polyfills, in this exact order -->
    <script src="node_modules/es6-shim/es6-shim.min.js"></script>
    <script src="node_modules/systemjs/dist/system-polyfills.js"></script>

    <script src="node_modules/angular2/bundles/angular2-polyfills.js"></script>
    <script src="node_modules/systemjs/dist/system.src.js"></script>
    <script src="node_modules/rxjs/bundles/Rx.js"></script>
    <script src="node_modules/angular2/bundles/angular2.dev.js"></script>

    <!-- 2. Configure SystemJS -->
    <script>
      System.config({
        packages: {
          app: {
            format: 'register',
            defaultExtension: 'js'
          }
        }
      });
      System.import('app/app')
            .then(null, console.error.bind(console));
    </script>

  </head>

  <!-- 3. Display the application -->
  <body>
    <my-app>Loading...</my-app>
  </body>

</html>

tsconfig.json

{
  "compilerOptions": {
    "target": "es5",
    "module": "system",
    "moduleResolution": "node",
    "sourceMap": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "removeComments": false,
    "noImplicitAny": false
  },
  "exclude": [
    "node_modules"
  ]
}

package.json

{
  "name": "angular2-quickstart",
  "version": "1.0.0",
  "scripts": {
    "tsc": "tsc",
    "tsc:w": "tsc -w",
    "lite": "lite-server",
    "start": "concurrent \"npm run tsc:w\" \"npm run lite\" "
  },
  "license": "ISC",
  "dependencies": {
    "angular2": "2.0.0-beta.2",
    "es6-promise": "^3.0.2",
    "es6-shim": "^0.33.3",
    "lodash": "^4.1.0",
    "reflect-metadata": "0.1.2",
    "rxjs": "5.0.0-beta.0",
    "systemjs": "0.19.6",
    "zone.js": "0.5.10"
  },
  "devDependencies": {
    "concurrently": "^1.0.0",
    "lite-server": "^1.3.4",
    "typescript": "^1.7.5"
  }
}

import {bootstrap}    from 'angular2/platform/browser'
import {Component} from 'angular2/core';
import * as _ from 'lodash';

@Component({
    selector: 'my-app',
    template: '<h1>My First Angular 2 App with lodash</h1>'
})
export class AppComponent {

    constructor(){
      console.log(_.last([1, 2, 3]));
  	  console.log('hello');
    }

}

bootstrap(AppComponent);
3
javascriptecmascript-6angular
check if you have lodash npm package installed. – Jai
milan@milan-desktop:~/Desktop/newapp$ npm install -S lodash npm WARN package.json [email protected] No description npm WARN package.json [email protected] No repository field. npm WARN package.json [email protected] No README data [email protected] node_modules/lodash – Milan Milanovic
I see lodash in node_modules and in package.json as well, all seems ok there... – Milan Milanovic
try with 'lodash/lodash' – Jai
here are installed modules (ls from terminal): angular2 concurrently es6-promise es6-shim lite-server lodash reflect-metadata rxjs systemjs twitter typescript zone.js – Milan Milanovic

3 Answers

14
votes

Perhaps you could try this configuration at SystemJS level:

System.config({
  (...)
  map: {
    lodash: 'node_modules/lodash/lodash.js'
  },
  meta: {
    lodash: { format: 'amd' }
  }
}

In a TS file, you can then use it as described below:

import _ from 'lodash';
_.forEach([1,2,3], function(e) {
  console.log(e);
});

This issue could help you: https://github.com/systemjs/systemjs/issues/951.

Thierry

2
votes

Fully working:

Install all thru terminal:

npm install lodash --save
tsd install lodash --save

Add paths in index.html

<script>
    System.config({
        packages: {
            app: {
                format: 'register',
                defaultExtension: 'js'
            }
        },
        paths: {
            lodash: './node_modules/lodash/lodash.js'
        }
    });
    System.import('app/init').then(null, console.error.bind(console));
</script>

Import lodash at the top of the .ts file

import * as _ from 'lodash'
0
votes

I solved importing lodash in the following way:

import * as _ from 'lodash';

and in systemjs.config.js i defined this:

map: { 'lodash' : 'node_modules/lodash/lodash.js' }