@tango-ts/adapters

Responsibility

Runtime adapters for Tango's Web-standard Request / Response handlers. This package owns the Node server adapter and the Vercel adapter (@tango-ts/adapters/vercel). It does not own routing, views, ORM behavior, or migrations.

What it responds to

• A Web handler: (request: Request) => Response | Promise<Response>.
• Node IncomingMessage / ServerResponse from the local HTTP server.

Functionality

• createNodeServer(handler, { logger, maxBodyBytes }) — creates a Node http.Server from a Web handler.
• serve(handlerOrServer, { host, port, logger, maxBodyBytes }) — starts a server and returns { server, url, close() }. close() drops idle keep-alive sockets and waits for in-flight requests.
• JSON 500 envelope for unexpected handler errors; the error itself is reported to the configured Logger (default: structured console logging) so failures are never silent.
• Request bodies are size-capped while streaming (default 10 MiB) and rejected with a JSON 413 envelope.
• vercelHandler(handler) (from @tango-ts/adapters/vercel) — wraps a project in Vercel's fetch web-handler export for the Node.js runtime. A subpath export so Vercel bundles never pull in node:http. Edge runtime is not supported (mysql2 needs TCP).

Design patterns that matter here

• Web core stays pure: adapters translate platform IO into Web requests, then get out of the way.
• Serverless-compatible shape: the same handler can later be wrapped for Lambda, Vercel, or Cloudflare.
• No any: Node stream chunks are narrowed from unknown before conversion.

Public contract

Everything exported from src/index.ts.

Testing

• Unit/integration (test/node.test.ts): starts an ephemeral local server, sends real HTTP requests with fetch, verifies request forwarding and error envelopes, then closes the server.
• Unit (test/vercel.test.ts): the Vercel fetch handler proxies requests and propagates rejections.
• Package (test/exports.package.ts): the ./vercel subpath export resolves from the built artifact through package.json exports.