feat: add HTTP server adapter and request-mapping tests

src/server.js

@@ -0,0 +1,79 @@
+"use strict";
+
+const http = require("node:http");
+const { buildApp } = require("./app");
+const { config } = require("./config");
+
+function readBody(req) {
+  return new Promise((resolve, reject) => {
+    let data = "";
+    req.setEncoding("utf8");
+    req.on("data", (chunk) => {
+      data += chunk;
+      if (data.length > 2_000_000) {
+        reject(new Error("payload_too_large"));
+      }
+    });
+    req.on("end", () => resolve(data));
+    req.on("error", reject);
+  });
+}
+
+function normalizeHeaders(rawHeaders) {
+  return Object.fromEntries(
+    Object.entries(rawHeaders || {}).map(([k, v]) => [
+      String(k).toLowerCase(),
+      Array.isArray(v) ? v.join(",") : (v || ""),
+    ]),
+  );
+}
+
+function mapToAppRequest({ req, rawBody }) {
+  const url = new URL(req.url, "http://localhost");
+  return {
+    method: req.method || "GET",
+    path: url.pathname,
+    headers: normalizeHeaders(req.headers),
+    rawBody,
+  };
+}
+
+function createHttpServer({ app }) {
+  return http.createServer(async (req, res) => {
+    try {
+      const rawBody = await readBody(req);
+      const response = app.handleRequest(mapToAppRequest({ req, rawBody }));
+
+      res.statusCode = response.status;
+      for (const [key, value] of Object.entries(response.headers || {})) {
+        res.setHeader(key, value);
+      }
+      res.end(response.body || "");
+    } catch (error) {
+      res.statusCode = 500;
+      res.setHeader("content-type", "application/json; charset=utf-8");
+      res.end(JSON.stringify({ error: error.message || "internal_error" }));
+    }
+  });
+}
+
+function start() {
+  const app = buildApp({ config });
+  const server = createHttpServer({ app });
+
+  server.listen(config.port, () => {
+    // eslint-disable-next-line no-console
+    console.log(`xartaudio server listening on :${config.port}`);
+  });
+}
+
+if (require.main === module) {
+  start();
+}
+
+module.exports = {
+  mapToAppRequest,
+  normalizeHeaders,
+  createHttpServer,
+  start,
+};