TypeScript setup

You'll need TypeScript 2.0 or greater to use Alsatian so go ahead and install it!

npm install typescript --save-dev

Add your tsconfig.json more info on creating this here and ensure it contains the experimentalDecorators flag set to true.

{
   "compilerOptions": {
      ...
      "experimentalDecorators": true,
      ...
   }
   ...
}

Now for installing alsatian it's simple, we're on NPM

npm install alsatian --save-dev

Write some tests and run them

alsatian "./**/*.spec.ts"

And you're done! :)

Targeting ES5 or ES3?

You may get a build error along the lines of

node_modules/alsatian/core/decorators/async-test-decorator.d.ts(2,149): error TS2304: Cannot find name 'Promise'.
node_modules/alsatian/core/running/test-item.d.ts(10,27): error TS2304: Cannot find name 'Promise'.
node_modules/alsatian/core/running/test-runner.d.ts(9,46): error TS2304: Cannot find name 'Promise'.

Fear not though all you need to do is add es2015 to your tsconfig.json compilerOptions libs

{
   "compilerOptions": {
      ...
      "lib": [ "es2015" ],
      ...
   }
   ...
}