Overloads and Callbacks Don’t write separate overloads that differ only on callback arity:

Update tsconfig.json Now that Angular 2 and its dependencies are installed, we need to enable TypeScript’s experimental support for decorators

Global Libraries A global library is one that can be accessed from the global scope (i.e. without using any form of import)

Organizing Types Documentation The greeter object can log to a file or display

Using tsconfig.json By invoking tsc with no input files, in which case the compiler searches for the tsconfig.json file starting

Property Decorators A Property Decorator is declared just before a property declaration. A property decorator cannot be used in a declaration

Babel First install Babelify and the Babel preset for ES2015. Like Uglify, Babelify mangles code, so we’ll need vinyl-buffer and gulp-sourcemaps

Write a simple Angular app in TypeScript First, change the code in app.ts to:

Exhaustiveness checking We would like the compiler to tell us when we don’t cover all variants of the discriminated union. For example, if we

Intersection Types An intersection type combines multiple types into one. This allows you to add together existing types to get a single type