IntelliJ IDEA 2017.3 Help

JavaScript

This feature is only supported in the Ultimate edition.

With IntelliJ IDEA, you can develop modern web, mobile, and desktop applications with JavaScript and Node.js. IntelliJ IDEA supports JavaScript and TypeScript programming languages, React and Angular frameworks and provides tight integration with various tools for web development.

On this page you will find a short Getting Started Guide that will walk you step by step from creating a web application to debugging and testing it.

Creating a new application

  1. Choose File | New | Project on the main menu or click the New Project button on the Welcome screen.
  2. In the Project Category and Options dialog, which is the first page of the New Project wizard, choose Static Web in the left-hand pane.
  3. In the right-hand pane, choose Static Web again and click Next.
  4. On the second page of the wizard, specify the project name and the path to the folder where the project-related files will be stored. Click Finish.

Starting with an existing JavaScript application

If you are going to continue developing an existing JavaScript application, open it in IntelliJ IDEA, choose the JavaScript version to use, and configure the libraries in it. Optionally download the required npm dependencies.

If the application sources are already on your machine
Click Open on the Welcome screen or choose File | Open on the main menu. In the dialog that opens, select the folder where your sources are stored.

If the application sources are under version control

  1. Click Check out from Version Control on the Welcome screen or choose VCS | Check out from Version Control on the main menu.
  2. Select your version control system from the list.
  3. In the VCS-specific dialog that opens, type your credentials and the repository to check out the application sources from.

Choosing the JavaScript language version

To get reliable and efficient coding assistance, you need to specify the language version that will be used in all JavaScript files of your application by default.

To choose the JavaScript language version

  1. In the Settings/Preferences dialog (Ctrl+Alt+S), choose JavaScript under Languages and Frameworks. The JavaScript page opens.
  2. From the drop-down list, choose one of the supported JavaScript language versions:

Using multiple JavaScript versions

If you are working on an application that uses both ECMAScript 5.1 and a newer version of ECMAScript, or JSX, or Flow, the easiest way is to choose the highest language version for the whole project from the drop-down list on the JavaScript page. For example, if you use ES5.1 and JSX, enable JSX (since it is a superset of ES5.1 and ES6).

To configure different JavaScript language versions for different folders

  1. On the JavaScript page, click browseButton next to the JavaScript language version drop-down list. The JavaScript Language Versions dialog opens.
  2. Click add and in the dialog that opens select the folder where you need a custom language version. IntelliJ IDEA brings you back to the JavaScript Language Versions dialog where the selected folder is shown in the Path field.
  3. From the Language drop-down list, choose the language version for the files in the selected folder. In all the other JavaScript files in the project IntelliJ IDEA will use the version chosen on the JavaScript page.
ws_js_choose_language_version.png

Configuring coding assistance for JavaScript library files

When working on a full-stack JavaScript application, it may be helpful to keep in mind that IntelliJ IDEA and the runtime treat JavaScript library .js file depending on their location:

  • When a library .js file is in your the project structure, next to the source files, it is available both for the runtime and for IntelliJ IDEA. IntelliJ IDEA includes its objects in the internal project index and uses them in code completion, syntax highlighting, and navigation. To make such library .js file more light-weight, configure it as an external library, then IntelliJ IDEA treats it as read-only and does not run any code inspections in it. And last but not the least, you can optionally specify a URL to retrieve library documentation from.
  • When a library .js file is referenced through a CDN link, it is available for the runtime but is invisible for IntelliJ IDEA. To add the objects from such library .js file to completion lists, download the file and configure it as an external library.
  • When a library .js file is on your machine elsewhere outside your project, it is invisible both for the runtime and for IntelliJ IDEA. To get coding assistance for its objects, you need to configure it as a library. However, even after that the browser will not load such library.
All the libraries configured for your project are listed on the JavaScript. Libraries page, see Configuring JavaScript Libraries for details.

Downloading npm dependencies

If your application uses some tools, libraries, or frameworks, download the required packages.

  1. Download, install, and configure Node.js as described in Configuring Node.js Interpreters.
  2. Install and enable the NodeJS plugin on the Plugins page as described in Installing, Updating and Uninstalling Repository Plugins and Enabling and Disabling Plugins.

To install a package in an empty project
Open the embedded Terminal (View | Tool Windows | Terminal) and type npm install <package name> at the command prompt.

If you already have a package.json file in your project
Right-click the package.json file in the editor or in the Project tool window and choose Run 'npm install' on the context menu.

Running JavaScript in browser

  1. In the editor, open the HTML file with the JavaScript reference. This HTML file does not necessarily have to be the one that implements the starting page of the application.
  2. Do one of the following:
    • Choose View | Open in Browser on the main menu or press Alt+F2. Then select the desired browser from the pop-up menu.
    • Hover your mouse pointer over the code to show the browser icons bar: browserIcons Click the icon that indicates the desired browser.

Debugging JavaScript

IntelliJ IDEA provides a built-in debugger for your client-side JavaScript code that works with Chrome.
You can also debug your client-side JavaScript in Firefox, version 36 and higher. However it is strongly recommended that you use Chrome or any other browser of the Chrome family. With IntelliJ IDEA, you can debug JavaScript applications running on the built-in server, on an external server, or on a remote server. For details, see Debugging JavaScript in Chrome and Debugging JavaScript in Firefox.

Last modified: 16 December 2017

See Also

Language and Framework-Specific Guidelines: