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 1,000,000+ packages pre-installed, including fast-check. Try it out:
const fc = require('fast-check');
// Function under test
function isSubstring(pattern, text) {
return text.indexOf(pattern) !== -1;
}
// Property based test
fc.assert(
fc.property(fc.string(), fc.string(), fc.string(), (a, b, c) => {
// For any a, b, c strings
// b is a substring of a + b + c
return isSubstring(b, a + b + c);
}),
);
- all documents on RunKit are public
require()any package directly from npm- use arrow functions, classes, template strings, and most of ES6
awaitany promise instead of using callbacks (example)- create your own embedded node.js snippets
This service is provided by RunKit and is not affiliated with npm, Inc or the package authors.