Sign Up for Free

RunKit +

Try any Node.js package right in your browser

This is a playground to test code. It runs a full Node.js environment and already has all of npm’s 400,000 packages pre-installed, including typefail with all npm packages installed. Try it out:

typefail lists no main file and has no index.js, so it can't be directly required. If this is a mistake, please let us know. It may however contain internal files that you can require manually:

// require("typefail/[??]")

This service is provided by RunKit and is not affiliated with npm, Inc or the package authors.

typefail v0.2.1

Test for expected compile-time errors in Typescript

typefail

Test for expected compile-time errors in Typescript

Overview

Static type checking is one of the major benefits of Typescript, so we create ambient typings to get static type checking with Javascript libraries, but we typically only test those typings for on good code. We run the tsc compiler and move on if it compiles. We don't normally make sure that those typings produce compile-time errors on bad type assignments, which is their actual purpose. This library and CLI provides a way to do this by embedding declarations within the code that tests the typings.

There are also times when we may want to make sure that pure Typescript libraries produce compile-time errors. We normally rely on Typescript to verify type assignments at build time, but Typescript is evolving, and the behavior of edge cases may change over time. Sometimes it's important to include in a library's test suite a confirmation of the behavior that the library expects of Typescript in these edge cases. The present library and CLI is useful for this purpose too.

This module was originally inspired by the module typings-tester.

Usage

// UNDER CONSTRUCTION

CLI

// UNDER CONSTRUCTION

API

// UNDER CONSTRUCTION

Metadata

RunKit is a free, in-browser JavaScript dev environment for prototyping Node.js code, with every npm package installed. Sign up to share your code.
Sign Up for Free