A Tern plugin adding Closure support.

pushedAt 6 years ago



tern-closure is a plugin which adds support for Closure Compiler annotations and the Closure type system to the JavaSript code intelligence system Tern.

To use tern-closure, you need to install it and then configure Tern to load it.


tern-closure adds the following features to your Tern installation:

  1. Understanding of types in JSDoc type annotations (similar to the doc_comment plugin included with Tern).
  2. Understanding of inheritance and interfaces with @extends and @implements.
  3. Completion and go-to-definition support for type names in JSDoc comments and in strings (e.g. @type annotations and goog.require arguments).
  4. Automatic loading of the definitions for types, so that you get completion and type information from other files and can jump to definitions in those files. This requires enabling a finder. We consider access modifiers and how types are used in order to load only the types relevant the files you are editing, keeping this feature feasible even for large projects.


Currently, tern-closure only works with the NodeJS Tern Server, and not within a browser.

Short version

After installing Tern according the setup instructions of your desired editor plugin, go to the place where the Tern package was installed (or the Tern repo was cloned) and run

$ npm install tern-closure

Or, if you're not sure where Tern was installed, you can try

$ npm install -g tern-closure

Long version

See INSTALL.md for instructions tailored to each editor.


In order for Tern to load the tern-closure plugin once it is installed, you must include closure in the plugins section of your Tern configuration file. The configuration file can be either a file named .tern-project in your project's root directory, or .tern-config in your home directory.

You must also explicitly disable the default doc_comment plugin, which will interfere with tern-closure.

Here is a minimal example .tern-project configuration file:

  "plugins": {
    "doc_comment": false,
    "closure": {}

"Project directory" and .tern-project vs .tern-config

Tern looks for .tern-project first, walking up the directory tree, and uses its location as the "project directory". If no .tern-project is found, your .tern-config is loaded instead, and the working directory of the Tern server process is used as the "project directory".

Since Tern and tern-closure (including finders like grep) use the "project directory" as the base for all relative paths, you should either use .tern-project or be careful about where you start your Tern server (or, where your editor plugin starts your Tern server).


You can set the following options in the closure section of your Tern configuration file:

  • finder Object. Configuration for finding the files that provide types. See Finders below. Optional. Default: None.
  • debug boolean. Whether tern-closure should print debug output. Optional. Default: Match Tern debug option.
  • noMinimalLoad boolean. When a finder is active, this disables attempts to limit loaded files according to visibility. This is mostly for debugging - if setting this fixes an issue, file a bug. Optional. Default: false.


tern-closure uses "finders" to find the files providing Closure names via goog.provide. Finders allow tern-closure to load and interpret the files providing names required via goog.require or referenced in JSDoc type strings so it better understands the context of a given file.

The finder section of the options object for closure in your .tern-project file specifies what finder implementation you want to use, and what options you want to pass to the finder. By default, no finder is used, and files are not automatically loaded. Currently, only one finder implementation is included with tern-closure, grep.

Common finder options:

  • name The name of the finder you want to use. Required.
  • debug Whether the finder should print debug output. Optional. Default: Match tern-closure debug option.


This is a basic finder which uses the grep command-line utility (or findstr in Windows) to search for goog.provide statements at startup and create a map of Closure names to providing files.


  • dirs An array of path strings indicating which directories to search for files. Paths can either be absolute, or relative to the project directory. Optional. Default: ['.'] (just the project directory).

Here is an example .tern-project file using the grep finder:

  "plugins": {
    "doc_comment": false,
    "closure": {
      "finder": {
        "name": "grep",
        "dirs": [

Additional finders

You can easily use a finder not included in this repository, or implement your own. This allows you to search for names in different ways, on demand, and to use existing indexes of your codebase.

Given a finder name name, tern-closure first looks in its own lib/finder directory, then attempts to load name using require(), so a third-party finder module can be installed as an npm package.

A finder module must implement a simple interface:

  • It must export a constructor function(projectDir: string, options: Object) which takes the project directory and an options object as parameters. Options are specified in the Tern configuration file.

  • Instances of that constructor must have a method findFile(name: string, cb: function(file: string)), which takes as arguments a Closure name name to find and a callback function cb to call with the path to file providing name. cb should be called asynchronously, even if the providing file is known when findFile is called. This allows finders to execute I/O operations to find files on demand.

Please note that while tern-closure is in a 0.X.X release, the finder API may be subject to breaking changes.

Bug reports and feature requests

Please file bug reports and feature requests as issues on the issues page of the tern-closure repository.


Pull requests to tern-closure are welcome. Please see the CONTRIBUTING.md file for requirements and guidelines.

Disclaimer: tern-closure is not an official Google product, and is maintained on a best-effort basis.

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