Add to CONTRIBUTING doc

CONTRIBUTING.md

@@ -123,3 +123,46 @@ rules:
   _danielyxie/bitburner_ and the base is _dev_.
 - Do not check in any generated files under `doc\`. The documentation is built
   automatically by ReadTheDocs.
+
+## Tests
+
+There are a few unit tests written using [jest](https://jestjs.io/), and some browser automation tests using [Cypress](https://www.cypress.io/).
+
+### Unit Tests
+
+Run unit tests with:
+
+```sh
+$ npm run test
+$ npm run test:watch # to re-run tests on changes
+```
+
+Tests go in the `/test` directory.
+
+### Browser Tests
+
+There are full browser automation tests which cover some basic "does it work" functionality.
+
+Run these with:
+
+```sh
+$ npm run build
+$ npm run cy:test
+```
+
+To start up the tests in watch mode (re-run on changes), which will also start up a dev server:
+
+```sh
+$ npm run cy:dev
+```
+
+## TypeScript Setup
+
+This project uses [Project References](https://www.typescriptlang.org/docs/handbook/project-references.html)
+to make sure that jest and Cypress tests only exist within Jest/Cypress code.
+
+To type-check the whole project:
+
+```sh
+$ npm run typescript
+```

package.json

@@ -137,6 +137,7 @@
     "lint": "npm run lint:jsts & npm run lint:style",
     "lint:jsts": "eslint --fix . --ext js,jsx,ts,tsx",
     "lint:style": "stylelint --fix ./css/*",
+    "typescript": "tsc --build",
     "preinstall": "node ./scripts/engines-check.js",
     "test": "jest",
     "test:watch": "jest --watch",