DefinitelyTyped

In order to effectively write your Meteor app with TypeScript, there are a few things you will need to do since simply referencing this Meteor type definition file and renaming all of your *.js files to *.ts will not work.

##Referencing Meteor type definitions in your app

Place the meteor.d.ts file in a directory (maybe <app root dir>/lib/typescript)
Add /// <reference path='../lib/typescript/meteor.d.ts'/> to the top of any TypeScript file

This will make these typed Meteor variables/objects available across your application:

Meteor
Session
Deps
Accounts
Match
Computation
Dependency
EJSON
HTTO
Email
Assets
DPP

Please note that the Template variable is not automatically available. You need to follow the instructions below to use the Template variable.

##Defining Templates In order to call Template.yourTemplateName.method, you will need to create a simple TypeScript definition file that declares a Template variable containing a list of template view-models/managers of type IMeteorViewModel (or IMeteorManager, which is the same as IMeteorViewModel). A good place for this definition could be <app root dir>/client/views/view-model-types.d.ts. Here is an example of that file:

/// <reference path='../../lib/typescript/meteor.d.ts'/>

declare var Template: {
  newPosts: IMeteorViewModel;
  bestPosts: IMeteorViewModel;
  postsList: IMeteorViewModel;
  comment: IMeteorViewModel;
  commentSubmit: IMeteorViewModel;
  notifications: IMeteorViewModel;
  postPage: IMeteorViewModel;
  postEdit: IMeteorViewModel;
  postItem: IMeteorViewModel;
  postNew: IMeteorViewModel;
  header: IMeteorViewModel;
}

After you create this file, you may access the Template variable by declaring something like /// <reference path='../view-model-types.d.ts'/> at the top of any TypeScript file containing references to Template. Something like Template.postsList.helpers() would then transpile successfully (and have the benefits of typing).

##Defining Collections In TypeScript, creating global variables is not allowed, and in a Meteor app, creating local variables (using var <varName>) limits variables' scope to the file. However, you will probably want to define variables, such as collections, that can be used across files. In the case of collections, one way to work around these limitations is to wrap each collection within a module, and then make the module globally accessible. Here is an example using posts.ts:

module PostsModel {
  export var Posts = new Meteor.Collection('posts');
};

this.PostsModel = PostsModel;

You can then access the Posts collection by placing /// <reference path='../../../collections/posts.ts'/> at the top of a TypeScript file. The code would look like this:

PostsModel.Posts.findOne(Session.get('currentPostId'));

##Reference app A simple Meteor application created with TypeScript is listed below. It is based on the Microscope reference app in Discover Meteor.

Sample Site: http://microscopic-typescript.meteor.com/
Code (TypeScript and transpiled JS): https://github.com/fullflavedave/MicroscopicTypeScript

##Meteor package There will hopefully be a Meteor package soon listed on Atmosphere that can be easily added using "mrt add meteor".