Node response patching

[pmelab]

Changes

• Uses node-fetch to enable response patching in Node.
• Adds integration tests for response patching in Node.

GitHub

• Fixes Response patching in Node fails #264

Roadmap

• Ensure call signature of window.fetch and node-fetch is compatible. Line out the corner-cases and limitations.
• Ensure that node-fetch doesn't get bundled and executed on the client

[kettanaito]

Thank you for these changes, @pmelab! I've had a few suggestions, do you mind take a look?

[pmelab]

@kettanaito Thank you for the review! I did the requested changes, and CI passed.

What's open are two TODOs I left in the code: The type definitions for RequestInit and Response in the browser and node-fetch are (in theory) not fully compatible and I did not find a way to make them so. In practice, I'm pretty sure they are. As far as I can tell, cross-fetch and isomorphic-fetch simply pretend compatibility in their type definitions.

[kettanaito]

Thank you for the adjustments! Looks amazing. I share your caution regarding type definition (call signature compatibility). We need to research what are the exact limitations between in-browser fetch and node-fetch, apart from environment limitation (like absolute URLs in Node). My initial assumption is that everything fetch does should be able to reproduce with http, which I assume node-fetch uses under the hood.

[kettanaito]

Hey. I've updated the feature branch against the latest master. Also added two more integration tests that asserts bypass/fall-through behavior (the difference between using ctx.fetch and native fetch directly). I've checked and confirm that node-fetch is not required when working in a browser, and I find the call signatures of window.fetch and node-fetch compatible.

[kettanaito]

Thank you for improving the library! Welcome to contributors 🎉