feat: add HTTP server adapter and request-mapping tests

test/server.test.js

@@ -0,0 +1,31 @@
+"use strict";
+
+const test = require("node:test");
+const assert = require("node:assert/strict");
+const { mapToAppRequest, normalizeHeaders } = require("../src/server");
+
+test("normalizeHeaders lowercases and joins array values", () => {
+  const headers = normalizeHeaders({
+    "X-User-Id": "u1",
+    "X-Forwarded-For": ["a", "b"],
+  });
+
+  assert.equal(headers["x-user-id"], "u1");
+  assert.equal(headers["x-forwarded-for"], "a,b");
+});
+
+test("mapToAppRequest extracts method/path/headers/body correctly", () => {
+  const request = mapToAppRequest({
+    req: {
+      method: "POST",
+      url: "/api/webhooks/x?debug=1",
+      headers: { "X-Signature": "sha256=abc" },
+    },
+    rawBody: "{\"ok\":true}",
+  });
+
+  assert.equal(request.method, "POST");
+  assert.equal(request.path, "/api/webhooks/x");
+  assert.equal(request.headers["x-signature"], "sha256=abc");
+  assert.equal(request.rawBody, "{\"ok\":true}");
+});