A Port of Suave.io to TypeScript as Express Middleware.
The entire library is designed to be WebParts all the way down. All filters and writers create WebParts and there are combinators to combine multiple WebParts into a single WebPart.
The choose function in /src/webPart takes an array of WebPart objects and attempts each one in order until it finds one that matches and then uses that WebPart to serve the response.
The pipe function in /src/webPart takes an array of WebPart objects and combines them all together to create a new WebPart object.
To plug this into the Express ecosystem, simply pass a WebPart to the run function from /src/web and pass the result to the app.use command from Express. See /examples for some examples.