WIP - TypeScript Support Doc

source/_data/sidebar.yml

@@ -25,8 +25,11 @@ guides:
     screenshots-and-videos: screenshots-and-videos.html
     launching-browsers: launching-browsers.html
     web-security: web-security.html
-    reporters: reporters.html
+  tooling:
     plugins-guide: plugins-guide.html
+    reporters: reporters.html
+    typescript-support: typescript-support.html
+
   # advanced-cypress:
     # the-cypress-workflow: the-cypress-workflow.html
     # coming-from-selenium: coming-from-selenium.html

source/api/introduction/api.md

@@ -44,6 +44,10 @@ Each document attempts to cover the essentials of each method including:
 
 **See also:** Other related methods.
 
+# IntelliSense
+
+IntelliSense is available for Cypress. It offers intelligent parameter information when writing Cypress commands directly in your IDE. {% url "Learn how to set up IntelliSense." typescript-support#IntelliSense %}
+
 # Reporting a Problem
 
 If you spot a typo, broken link, incorrect code sample or want to contribute to improve the documentation, we're happy to have your help!

source/guides/tooling/typescript-support.md

@@ -0,0 +1,45 @@
+---
+title: TypeScript Support
+comments: false
+---
+
+Cypress ships with {% url "official type declarations" https://github.com/cypress-io/cypress/tree/develop/cli/types %} for {% url "TypeScript" https://www.typescriptlang.org/ %}.
+
+# IntelliSense
+
+IntelliSense is available for Cypress. It offers intelligent parameter information directly in your IDE while writing tests. While TypeScript is used to generate the data for intellisense, you can make use of intellisense even when writing your tests in plain JavaScript. 
+
+## Triple-Slash Directives
+
+Adding a {% url "triple-slash directive" "http://www.typescriptlang.org/docs/handbook/triple-slash-directives.html" %} to the head of your JavaScript or TypeScript testing file should get intellisense working in most IDEs.
+
+```js
+/// <reference types="Cypress" />
+```
+{% img /img/guides/typescript-intellisense-with-reference.gif %}
+
+## tsconfig.json
+
+If you want to write your tests in TypeScript, you may find it more convenient to add a {% url "`tsconfig.json`" http://www.typescriptlang.org/docs/handbook/tsconfig-json.html %} inside your `cypress` folder.
+
+```json
+{
+  "compilerOptions": {
+	"strict": true,
+    "baseUrl": "../node_modules",
+    "target": "es5",
+    "lib": ["es5", "dom"],
+    "types": ["cypress"],
+  },
+  "include": [
+    "**/*.ts"
+  ]
+}
+```
+
+The `"types"` will tell the TypeScript compiler to only include type definitions from Cypress. This will address instances where the project also uses `@types/chai` or `@types/jquery`. Since {% url "Chai" bundled-tools#Chai %} and {% url "jQuery" bundled-tools#Other-Library-Utilities %} are namespaces (globals), incompatible versions will cause the package manager (`yarn` or `npm`) to nest and include multiple definitions and cause conflicts.
+
+# Examples
+
+- {% url "TypeScript with WebPack" https://github.com/cypress-io/cypress-example-recipes/tree/master/examples/preprocessors__typescript-webpack %}
+- {% url "TypeScript with Browserify" https://github.com/cypress-io/cypress-example-recipes/tree/master/examples/preprocessors__typescript-browserify %}

themes/cypress/languages/en.yml

@@ -69,6 +69,8 @@ sidebar:
     cypress-api-design: API Design
     all-videos: Videos
     plugins-guide: Plugins
+    tooling: Tooling
+    typescript-support: TypeScript Support
   api:
     introduction: Introduction
     api: API