From 27c94677dfc66b1bb6da74e76acd105dfbe092a7 Mon Sep 17 00:00:00 2001
From: Tomasz Andrzejak <andreiltd@gmail.com>
Date: Wed, 24 Jun 2026 10:26:26 +0200
Subject: [PATCH] refactor(p3-shim): migrate preview3-shim package to ts

This is based on recent refactor of preview2-shim.
---
 packages/preview3-shim/.gitignore             |  2 ++
 packages/preview3-shim/package.json           | 29 +++++++++++------
 .../{lib/nodejs/cli.js => src/nodejs/cli.ts}  | 21 ++++++++----
 .../nodejs/clocks.js => src/nodejs/clocks.ts} |  0
 .../nodejs/filesystem.ts}                     |  0
 .../nodejs/filesystem/descriptor.ts}          |  0
 .../nodejs/filesystem/error.ts}               |  4 ++-
 .../nodejs/filesystem/utils.ts}               |  0
 .../nodejs/finalization.ts}                   |  4 +--
 .../nodejs/future.js => src/nodejs/future.ts} |  0
 .../nodejs/http.js => src/nodejs/http.ts}     |  0
 .../client.js => src/nodejs/http/client.ts}   |  4 ++-
 .../error.js => src/nodejs/http/error.ts}     |  6 ++--
 .../fields.js => src/nodejs/http/fields.ts}   |  0
 .../request.js => src/nodejs/http/request.ts} |  4 +--
 .../nodejs/http/response.ts}                  |  2 +-
 .../server.js => src/nodejs/http/server.ts}   |  1 +
 .../nodejs/index.js => src/nodejs/index.ts}   |  0
 .../nodejs/random.js => src/nodejs/random.ts} |  0
 .../sockets.js => src/nodejs/sockets.ts}      |  0
 .../nodejs/sockets/address.ts}                |  0
 .../error.js => src/nodejs/sockets/error.ts}  |  8 ++---
 .../nodejs/sockets/ip-name-lookup.ts}         |  0
 .../tcp.js => src/nodejs/sockets/tcp.ts}      |  1 +
 .../udp.js => src/nodejs/sockets/udp.ts}      |  0
 .../nodejs/stream.js => src/nodejs/stream.ts} |  4 +--
 .../nodejs/workers/cli-worker.ts}             |  0
 .../nodejs/workers/filesystem-worker.ts}      |  0
 .../nodejs/workers/http-worker.ts}            | 10 ++++--
 .../nodejs/workers/resource-worker.ts}        |  6 ++--
 .../nodejs/workers/tcp-worker.ts}             | 32 +++++++++----------
 .../nodejs/workers/udp-worker.ts}             | 12 +++----
 packages/preview3-shim/test/nop-worker.js     |  2 +-
 .../test/resource-worker.bench.js             |  2 +-
 .../test/resource-worker.test.js              |  2 +-
 packages/preview3-shim/tsconfig.build.json    | 11 +++++++
 packages/preview3-shim/tsconfig.json          | 21 ++++++++++++
 pnpm-lock.yaml                                | 17 ++++++++--
 pnpm-workspace.yaml                           |  1 +
 39 files changed, 141 insertions(+), 65 deletions(-)
 create mode 100644 packages/preview3-shim/.gitignore
 rename packages/preview3-shim/{lib/nodejs/cli.js => src/nodejs/cli.ts} (85%)
 rename packages/preview3-shim/{lib/nodejs/clocks.js => src/nodejs/clocks.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/filesystem.js => src/nodejs/filesystem.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/filesystem/descriptor.js => src/nodejs/filesystem/descriptor.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/filesystem/error.js => src/nodejs/filesystem/error.ts} (95%)
 rename packages/preview3-shim/{lib/nodejs/filesystem/utils.js => src/nodejs/filesystem/utils.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/finalization.js => src/nodejs/finalization.ts} (88%)
 rename packages/preview3-shim/{lib/nodejs/future.js => src/nodejs/future.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/http.js => src/nodejs/http.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/http/client.js => src/nodejs/http/client.ts} (97%)
 rename packages/preview3-shim/{lib/nodejs/http/error.js => src/nodejs/http/error.ts} (92%)
 rename packages/preview3-shim/{lib/nodejs/http/fields.js => src/nodejs/http/fields.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/http/request.js => src/nodejs/http/request.ts} (99%)
 rename packages/preview3-shim/{lib/nodejs/http/response.js => src/nodejs/http/response.ts} (98%)
 rename packages/preview3-shim/{lib/nodejs/http/server.js => src/nodejs/http/server.ts} (98%)
 rename packages/preview3-shim/{lib/nodejs/index.js => src/nodejs/index.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/random.js => src/nodejs/random.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/sockets.js => src/nodejs/sockets.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/sockets/address.js => src/nodejs/sockets/address.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/sockets/error.js => src/nodejs/sockets/error.ts} (96%)
 rename packages/preview3-shim/{lib/nodejs/sockets/ip-name-lookup.js => src/nodejs/sockets/ip-name-lookup.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/sockets/tcp.js => src/nodejs/sockets/tcp.ts} (99%)
 rename packages/preview3-shim/{lib/nodejs/sockets/udp.js => src/nodejs/sockets/udp.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/stream.js => src/nodejs/stream.ts} (98%)
 rename packages/preview3-shim/{lib/nodejs/workers/cli-worker.js => src/nodejs/workers/cli-worker.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/workers/filesystem-worker.js => src/nodejs/workers/filesystem-worker.ts} (100%)
 rename packages/preview3-shim/{lib/nodejs/workers/http-worker.js => src/nodejs/workers/http-worker.ts} (97%)
 rename packages/preview3-shim/{lib/nodejs/workers/resource-worker.js => src/nodejs/workers/resource-worker.ts} (97%)
 rename packages/preview3-shim/{lib/nodejs/workers/tcp-worker.js => src/nodejs/workers/tcp-worker.ts} (93%)
 rename packages/preview3-shim/{lib/nodejs/workers/udp-worker.js => src/nodejs/workers/udp-worker.ts} (94%)
 create mode 100644 packages/preview3-shim/tsconfig.build.json
 create mode 100644 packages/preview3-shim/tsconfig.json

diff --git a/packages/preview3-shim/.gitignore b/packages/preview3-shim/.gitignore
new file mode 100644
index 000000000..d2fcdb5a1
--- /dev/null
+++ b/packages/preview3-shim/.gitignore
@@ -0,0 +1,2 @@
+# TypeScript build outputs
+/dist/
diff --git a/packages/preview3-shim/package.json b/packages/preview3-shim/package.json
index 3b41e3628..c477ec64d 100644
--- a/packages/preview3-shim/package.json
+++ b/packages/preview3-shim/package.json
@@ -23,35 +23,44 @@
   },
   "files": [
     "types",
-    "lib"
+    "dist"
   ],
   "type": "module",
-  "types": "./types/index.d.ts",
   "exports": {
     ".": {
-      "types": "./types/index.d.ts",
-      "node": "./lib/nodejs/index.js"
+      "types": "./dist/nodejs/index.d.ts",
+      "node": "./dist/nodejs/index.js"
     },
     "./*": {
-      "types": "./types/*.d.ts",
-      "node": "./lib/nodejs/*.js"
+      "types": "./dist/nodejs/*.d.ts",
+      "node": "./dist/nodejs/*.js"
+    },
+    "./interfaces/*": {
+      "types": "./types/interfaces/*.d.ts"
     }
   },
   "scripts": {
-    "compile:check": "tsc --noEmit types/index.d.ts",
+    "build": "tsc --project tsconfig.build.json",
+    "build:watch": "tsc --watch",
+    "types:check": "tsc --noEmit",
     "fmt": "oxfmt",
     "fmt:check": "oxfmt --check",
     "lint": "oxlint",
     "lint:fix": "oxlint --fix",
+    "pretest": "pnpm run build",
     "test": "vitest --run",
-    "bench": "vitest bench --run"
+    "prebench": "pnpm run build",
+    "bench": "vitest bench --run",
+    "prepack": "pnpm run build"
   },
   "dependencies": {
-    "@bytecodealliance/preview2-shim": "^0.18.1"
+    "@bytecodealliance/preview2-shim": "^0.19.0"
   },
   "devDependencies": {
+    "@types/node": "^24.12.4",
     "globals": "^17.6.0",
+    "typescript": "catalog:",
     "vite": "^8.0.16",
-    "vitest": "^4.1.0"
+    "vitest": "catalog:"
   }
 }
diff --git a/packages/preview3-shim/lib/nodejs/cli.js b/packages/preview3-shim/src/nodejs/cli.ts
similarity index 85%
rename from packages/preview3-shim/lib/nodejs/cli.js
rename to packages/preview3-shim/src/nodejs/cli.ts
index 262b2d9f4..87b91c69f 100644
--- a/packages/preview3-shim/lib/nodejs/cli.js
+++ b/packages/preview3-shim/src/nodejs/cli.ts
@@ -5,9 +5,18 @@ import { ResourceWorker } from "./workers/resource-worker.js";
 import { StreamReader, readableByteStreamFromReader } from "./stream.js";
 import { future } from "./future.js";
 
-import { environment as environmentV2 } from "@bytecodealliance/preview2-shim/cli";
+import * as cliV2 from "@bytecodealliance/preview2-shim/cli";
 
-export {
+type Preview2NodeCli = typeof cliV2 & {
+  _appendEnv: (env: Record<string, string>) => void;
+  _setTerminalStdin: (terminalStdin: unknown) => void;
+  _setTerminalStdout: (terminalStdout: unknown) => void;
+  _setTerminalStderr: (terminalStderr: unknown) => void;
+};
+
+const nodeCliV2 = cliV2 as Preview2NodeCli;
+
+export const {
   _appendEnv,
   _setEnv,
   _setArgs,
@@ -21,15 +30,15 @@ export {
   terminalStdin,
   terminalStdout,
   terminalStderr,
-} from "@bytecodealliance/preview2-shim/cli";
+} = nodeCliV2;
 
 // `wasi:cli/environment` renamed `initial-cwd` to `get-initial-cwd` between
 // p2 and p3. Adapt the p2-shim shape to the p3 WIT member name while
 // re-exporting the unchanged members.
 export const environment = {
-  getEnvironment: environmentV2.getEnvironment,
-  getArguments: environmentV2.getArguments,
-  getInitialCwd: environmentV2.initialCwd,
+  getEnvironment: cliV2.environment.getEnvironment,
+  getArguments: cliV2.environment.getArguments,
+  getInitialCwd: cliV2.environment.initialCwd,
 };
 
 let WORKER = null;
diff --git a/packages/preview3-shim/lib/nodejs/clocks.js b/packages/preview3-shim/src/nodejs/clocks.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/clocks.js
rename to packages/preview3-shim/src/nodejs/clocks.ts
diff --git a/packages/preview3-shim/lib/nodejs/filesystem.js b/packages/preview3-shim/src/nodejs/filesystem.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/filesystem.js
rename to packages/preview3-shim/src/nodejs/filesystem.ts
diff --git a/packages/preview3-shim/lib/nodejs/filesystem/descriptor.js b/packages/preview3-shim/src/nodejs/filesystem/descriptor.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/filesystem/descriptor.js
rename to packages/preview3-shim/src/nodejs/filesystem/descriptor.ts
diff --git a/packages/preview3-shim/lib/nodejs/filesystem/error.js b/packages/preview3-shim/src/nodejs/filesystem/error.ts
similarity index 95%
rename from packages/preview3-shim/lib/nodejs/filesystem/error.js
rename to packages/preview3-shim/src/nodejs/filesystem/error.ts
index d9d55158b..d3262e6bf 100644
--- a/packages/preview3-shim/lib/nodejs/filesystem/error.js
+++ b/packages/preview3-shim/src/nodejs/filesystem/error.ts
@@ -56,6 +56,8 @@ function getErrorTag(e) {
  * Custom error for File operations with JCO compatible payload.
  */
 export class FSError extends Error {
+  payload;
+
   /**
    * @param {string} tag        – machine‐readable error tag
    * @param {string} [message]  – human‐readable message
@@ -63,7 +65,7 @@ export class FSError extends Error {
    * @param {object} [opts]
    * @param {Error} [opts.cause]
    */
-  constructor(tag, message, val, opts = {}) {
+  constructor(tag, message = undefined, val = undefined, opts: { cause?: unknown } = {}) {
     super(message ?? `Error: ${tag}`, { cause: opts.cause });
     this.name = "FSError";
     this.payload = val !== undefined ? { tag, val } : { tag };
diff --git a/packages/preview3-shim/lib/nodejs/filesystem/utils.js b/packages/preview3-shim/src/nodejs/filesystem/utils.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/filesystem/utils.js
rename to packages/preview3-shim/src/nodejs/filesystem/utils.ts
diff --git a/packages/preview3-shim/lib/nodejs/finalization.js b/packages/preview3-shim/src/nodejs/finalization.ts
similarity index 88%
rename from packages/preview3-shim/lib/nodejs/finalization.js
rename to packages/preview3-shim/src/nodejs/finalization.ts
index a685eaa8b..4b0a7db58 100644
--- a/packages/preview3-shim/lib/nodejs/finalization.js
+++ b/packages/preview3-shim/src/nodejs/finalization.ts
@@ -1,4 +1,4 @@
-let REGISTRY = null;
+let REGISTRY: FinalizationRegistry<() => void> | null = null;
 
 function getRegistry() {
   if (!REGISTRY) {
@@ -27,7 +27,7 @@ export function registerDispose(resource, parent = null, id, disposeFn) {
   return finalizer;
 }
 
-export function earlyDispose(finalizer) {
+export function earlyDispose(finalizer: () => void) {
   getRegistry().unregister(finalizer);
   finalizer();
 }
diff --git a/packages/preview3-shim/lib/nodejs/future.js b/packages/preview3-shim/src/nodejs/future.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/future.js
rename to packages/preview3-shim/src/nodejs/future.ts
diff --git a/packages/preview3-shim/lib/nodejs/http.js b/packages/preview3-shim/src/nodejs/http.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/http.js
rename to packages/preview3-shim/src/nodejs/http.ts
diff --git a/packages/preview3-shim/lib/nodejs/http/client.js b/packages/preview3-shim/src/nodejs/http/client.ts
similarity index 97%
rename from packages/preview3-shim/lib/nodejs/http/client.js
rename to packages/preview3-shim/src/nodejs/http/client.ts
index b0fabba65..801436bc1 100644
--- a/packages/preview3-shim/lib/nodejs/http/client.js
+++ b/packages/preview3-shim/src/nodejs/http/client.ts
@@ -1,3 +1,5 @@
+import { MessageChannel } from "node:worker_threads";
+
 import { ResourceWorker } from "../workers/resource-worker.js";
 import { StreamReader, readableByteStreamFromReader } from "../stream.js";
 import { FutureReader, future } from "../future.js";
@@ -63,7 +65,7 @@ export const client = {
     const { port1: tx, port2: rx } = new MessageChannel();
     const { port1: transmitRx, port2: transmitTx } = new MessageChannel();
 
-    const transfer = [rx, transmitTx];
+    const transfer = [rx, transmitTx] as any[];
     const stream = body ? readableByteStreamFromReader(body, { name: "request body" }) : undefined;
     if (stream) {
       transfer.unshift(stream);
diff --git a/packages/preview3-shim/lib/nodejs/http/error.js b/packages/preview3-shim/src/nodejs/http/error.ts
similarity index 92%
rename from packages/preview3-shim/lib/nodejs/http/error.js
rename to packages/preview3-shim/src/nodejs/http/error.ts
index 079a0ac59..a175f137a 100644
--- a/packages/preview3-shim/lib/nodejs/http/error.js
+++ b/packages/preview3-shim/src/nodejs/http/error.ts
@@ -4,13 +4,15 @@
  * https://bytecodealliance.github.io/jco/wit-type-representations.html#result-considerations-idiomatic-js-errors-for-host-implementations
  */
 export class HttpError extends Error {
+  payload;
+
   /**
    * Create a new WASI http error
    * @param {string} tag - The error tag/type
    * @param {string} [message] - Human-readable error message
    * @param {any} [val] - Optional value/data for the error
    */
-  constructor(tag, message, val, opts = {}) {
+  constructor(tag, message = undefined, val = undefined, opts: { cause?: unknown } = {}) {
     super(message || `Error: ${tag}`, { cause: opts.cause });
     this.name = "HttpError";
     this.payload = val !== undefined ? { tag, val } : { tag };
@@ -57,7 +59,7 @@ export class HttpError extends Error {
   }
 }
 
-function getFirstError(e) {
+function getFirstError(e: any) {
   if (typeof e !== "object" || e === null) {
     return e;
   }
diff --git a/packages/preview3-shim/lib/nodejs/http/fields.js b/packages/preview3-shim/src/nodejs/http/fields.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/http/fields.js
rename to packages/preview3-shim/src/nodejs/http/fields.ts
diff --git a/packages/preview3-shim/lib/nodejs/http/request.js b/packages/preview3-shim/src/nodejs/http/request.ts
similarity index 99%
rename from packages/preview3-shim/lib/nodejs/http/request.js
rename to packages/preview3-shim/src/nodejs/http/request.ts
index 0ff6d0a95..3f37c634a 100644
--- a/packages/preview3-shim/lib/nodejs/http/request.js
+++ b/packages/preview3-shim/src/nodejs/http/request.ts
@@ -209,7 +209,7 @@ export class Request {
    * @throws {HttpError} with payload.tag 'invalid-argument' for invalid arguments
    *
    */
-  static new(headers, contents, trailers, options) {
+  static new(headers, contents, trailers, options): [Request, FutureReader] {
     if (options != null && !(options instanceof RequestOptions)) {
       throw new HttpError("invalid-argument", "options must be RequestOptions");
     }
@@ -541,7 +541,7 @@ function readOpts(remaining) {
       ? remaining
       : BigInt(DEFAULT_BYTE_STREAM_CHUNK_SIZE),
   );
-  const opts = { count };
+  const opts: { count: number; rejectLength?: number } = { count };
   if (remaining <= BigInt(Number.MAX_SAFE_INTEGER)) {
     opts.rejectLength = Number(remaining);
   }
diff --git a/packages/preview3-shim/lib/nodejs/http/response.js b/packages/preview3-shim/src/nodejs/http/response.ts
similarity index 98%
rename from packages/preview3-shim/lib/nodejs/http/response.js
rename to packages/preview3-shim/src/nodejs/http/response.ts
index e9f7d0613..e8834752e 100644
--- a/packages/preview3-shim/lib/nodejs/http/response.js
+++ b/packages/preview3-shim/src/nodejs/http/response.ts
@@ -48,7 +48,7 @@ export class Response {
    * @returns {{ res: Response, future: FutureReader }}
    * @throws {HttpError} with payload.tag 'invalid-argument' for invalid arguments
    */
-  static new(headers, contents, trailers) {
+  static new(headers, contents, trailers): [Response, FutureReader] {
     if (!(headers instanceof Fields)) {
       throw new HttpError("invalid-argument", "headers must be Fields");
     }
diff --git a/packages/preview3-shim/lib/nodejs/http/server.js b/packages/preview3-shim/src/nodejs/http/server.ts
similarity index 98%
rename from packages/preview3-shim/lib/nodejs/http/server.js
rename to packages/preview3-shim/src/nodejs/http/server.ts
index e811dae93..3ac878537 100644
--- a/packages/preview3-shim/lib/nodejs/http/server.js
+++ b/packages/preview3-shim/src/nodejs/http/server.ts
@@ -1,4 +1,5 @@
 import { EventEmitter } from "node:events";
+import { MessageChannel } from "node:worker_threads";
 
 import { ResourceWorker } from "../workers/resource-worker.js";
 import { StreamReader, readableByteStreamFromReader } from "../stream.js";
diff --git a/packages/preview3-shim/lib/nodejs/index.js b/packages/preview3-shim/src/nodejs/index.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/index.js
rename to packages/preview3-shim/src/nodejs/index.ts
diff --git a/packages/preview3-shim/lib/nodejs/random.js b/packages/preview3-shim/src/nodejs/random.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/random.js
rename to packages/preview3-shim/src/nodejs/random.ts
diff --git a/packages/preview3-shim/lib/nodejs/sockets.js b/packages/preview3-shim/src/nodejs/sockets.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/sockets.js
rename to packages/preview3-shim/src/nodejs/sockets.ts
diff --git a/packages/preview3-shim/lib/nodejs/sockets/address.js b/packages/preview3-shim/src/nodejs/sockets/address.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/sockets/address.js
rename to packages/preview3-shim/src/nodejs/sockets/address.ts
diff --git a/packages/preview3-shim/lib/nodejs/sockets/error.js b/packages/preview3-shim/src/nodejs/sockets/error.ts
similarity index 96%
rename from packages/preview3-shim/lib/nodejs/sockets/error.js
rename to packages/preview3-shim/src/nodejs/sockets/error.ts
index 5d2a8f5a2..3bec26163 100644
--- a/packages/preview3-shim/lib/nodejs/sockets/error.js
+++ b/packages/preview3-shim/src/nodejs/sockets/error.ts
@@ -68,12 +68,14 @@ export const CODE_MAP = {
  * https://bytecodealliance.github.io/jco/wit-type-representations.html#result-considerations-idiomatic-js-errors-for-host-implementations
  */
 export class SocketError extends Error {
+  payload;
+
   /**
    * @param {string} tag        – machine‐readable error tag
    * @param {string} [message]  – human‐readable message
    * @param {any}    [val]      – optional extra data
    */
-  constructor(tag, message, val, opts = {}) {
+  constructor(tag, message = undefined, val = undefined, opts: { cause?: unknown } = {}) {
     super(message ?? `Error: ${tag}`, { cause: opts.cause });
     this.name = "SocketError";
     this.payload = val !== undefined ? { tag, val } : { tag };
@@ -88,9 +90,7 @@ export class SocketError extends Error {
       return err;
     }
 
-    let tag,
-      message = undefined,
-      val = undefined;
+    let tag, message, val;
 
     if (typeof err === "number") {
       tag = CODE_MAP[err] ?? "other";
diff --git a/packages/preview3-shim/lib/nodejs/sockets/ip-name-lookup.js b/packages/preview3-shim/src/nodejs/sockets/ip-name-lookup.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/sockets/ip-name-lookup.js
rename to packages/preview3-shim/src/nodejs/sockets/ip-name-lookup.ts
diff --git a/packages/preview3-shim/lib/nodejs/sockets/tcp.js b/packages/preview3-shim/src/nodejs/sockets/tcp.ts
similarity index 99%
rename from packages/preview3-shim/lib/nodejs/sockets/tcp.js
rename to packages/preview3-shim/src/nodejs/sockets/tcp.ts
index 7c5ce2282..f3e619065 100644
--- a/packages/preview3-shim/lib/nodejs/sockets/tcp.js
+++ b/packages/preview3-shim/src/nodejs/sockets/tcp.ts
@@ -93,6 +93,7 @@ export class TcpSocket {
     hopLimit: 1,
     receiveBufferSize: 65_536n,
     sendBufferSize: 65_536n,
+    listenBacklogSize: 128n,
   };
 
   /**
diff --git a/packages/preview3-shim/lib/nodejs/sockets/udp.js b/packages/preview3-shim/src/nodejs/sockets/udp.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/sockets/udp.js
rename to packages/preview3-shim/src/nodejs/sockets/udp.ts
diff --git a/packages/preview3-shim/lib/nodejs/stream.js b/packages/preview3-shim/src/nodejs/stream.ts
similarity index 98%
rename from packages/preview3-shim/lib/nodejs/stream.js
rename to packages/preview3-shim/src/nodejs/stream.ts
index eaad33218..90b7eb755 100644
--- a/packages/preview3-shim/lib/nodejs/stream.js
+++ b/packages/preview3-shim/src/nodejs/stream.ts
@@ -177,7 +177,7 @@ function assertByte(value) {
  * expect(done).toBeNull();
  *
  */
-export function stream(opts = {}) {
+export function stream(opts: { readableHWM?: number; writableHWM?: number } = {}) {
   const { readableHWM = 64 * 1024, writableHWM = 64 * 1024 } = opts;
 
   const transform = new TransformStream(
@@ -206,7 +206,7 @@ export class StreamReader {
    * @param {AsyncIterable|Iterable} source - An async or sync iterable to consume e.g. ReadableStream, async generator, array.
    * @throws {Error} If the provided source does not implement `[Symbol.asyncIterator]` or `[Symbol.iterator]`.
    */
-  constructor(source, opts = {}) {
+  constructor(source, opts: { preventCancel?: boolean } = {}) {
     if (
       !source ||
       (typeof source[Symbol.asyncIterator] !== "function" &&
diff --git a/packages/preview3-shim/lib/nodejs/workers/cli-worker.js b/packages/preview3-shim/src/nodejs/workers/cli-worker.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/workers/cli-worker.js
rename to packages/preview3-shim/src/nodejs/workers/cli-worker.ts
diff --git a/packages/preview3-shim/lib/nodejs/workers/filesystem-worker.js b/packages/preview3-shim/src/nodejs/workers/filesystem-worker.ts
similarity index 100%
rename from packages/preview3-shim/lib/nodejs/workers/filesystem-worker.js
rename to packages/preview3-shim/src/nodejs/workers/filesystem-worker.ts
diff --git a/packages/preview3-shim/lib/nodejs/workers/http-worker.js b/packages/preview3-shim/src/nodejs/workers/http-worker.ts
similarity index 97%
rename from packages/preview3-shim/lib/nodejs/workers/http-worker.js
rename to packages/preview3-shim/src/nodejs/workers/http-worker.ts
index 43d1cf4a8..3ff18b6fa 100644
--- a/packages/preview3-shim/lib/nodejs/workers/http-worker.js
+++ b/packages/preview3-shim/src/nodejs/workers/http-worker.ts
@@ -1,5 +1,6 @@
 import { Readable, Writable, PassThrough } from "node:stream";
 import { pipeline } from "stream/promises";
+import { MessageChannel } from "node:worker_threads";
 
 import { createServer } from "node:http";
 import { request as httpRequest, Agent as HttpAgent } from "node:http";
@@ -21,6 +22,9 @@ Router()
   .op("client-request", handleRequest);
 
 class Queue {
+  _items = [];
+  _resolvers = [];
+
   constructor() {
     this._items = [];
     this._resolvers = [];
@@ -62,7 +66,7 @@ async function handleHttpServerStart({ port, host }) {
 
   await new Promise((resolve, reject) => {
     server.on("error", reject);
-    server.listen(port, host, resolve);
+    server.listen(port, host, () => resolve(undefined));
   });
 
   servers.set(serverId, { server, pending, inflight });
@@ -343,7 +347,7 @@ function endRequest(req) {
     req.once("close", onClose);
 
     try {
-      req.end(() => settle(resolve));
+      req.end(() => settle(resolve, undefined));
     } catch (err) {
       settle(reject, err);
     }
@@ -410,7 +414,7 @@ const toObject = (entries) => {
 
 const encoder = new TextEncoder();
 
-const toEntries = (obj) => {
+const toEntries = (obj: Record<string, any>) => {
   return Object.entries(obj).flatMap(([k, v]) =>
     Array.isArray(v) ? v.map((val) => [k, encoder.encode(val)]) : [[k, encoder.encode(v)]],
   );
diff --git a/packages/preview3-shim/lib/nodejs/workers/resource-worker.js b/packages/preview3-shim/src/nodejs/workers/resource-worker.ts
similarity index 97%
rename from packages/preview3-shim/lib/nodejs/workers/resource-worker.js
rename to packages/preview3-shim/src/nodejs/workers/resource-worker.ts
index 06a59d268..55786857c 100644
--- a/packages/preview3-shim/lib/nodejs/workers/resource-worker.js
+++ b/packages/preview3-shim/src/nodejs/workers/resource-worker.ts
@@ -144,12 +144,12 @@ export function Router() {
   };
 }
 
-function serializeError(err) {
+function serializeError(err: any) {
   if (!(err instanceof Error)) {
     return err;
   }
 
-  const serialized = {
+  const serialized: any = {
     __resourceWorkerError: true,
     name: err.name,
     message: err.message,
@@ -167,7 +167,7 @@ function serializeError(err) {
   return serialized;
 }
 
-function deserializeError(err) {
+function deserializeError(err: any) {
   if (!err || typeof err !== "object" || err.__resourceWorkerError !== true) {
     return err;
   }
diff --git a/packages/preview3-shim/lib/nodejs/workers/tcp-worker.js b/packages/preview3-shim/src/nodejs/workers/tcp-worker.ts
similarity index 93%
rename from packages/preview3-shim/lib/nodejs/workers/tcp-worker.js
rename to packages/preview3-shim/src/nodejs/workers/tcp-worker.ts
index 6d89ff60c..fb3afda58 100644
--- a/packages/preview3-shim/lib/nodejs/workers/tcp-worker.js
+++ b/packages/preview3-shim/src/nodejs/workers/tcp-worker.ts
@@ -8,10 +8,10 @@ import { serializeIpAddress, makeIpAddress, ipAddressConflict } from "../sockets
 import { SocketError } from "../sockets/error.js";
 
 import process from "node:process";
-const { TCP, constants: TCPConstants } = process.binding("tcp_wrap");
+const { TCP, constants: TCPConstants } = (process as any).binding("tcp_wrap");
 
 // Socket instances stored by ID
-const sockets = new Map();
+const sockets = new Map<any, any>();
 // Unique IDs for sockets
 let NEXT_SOCKET_ID = 0n;
 
@@ -69,12 +69,12 @@ async function handleTcpBind({ socketId, localAddress }) {
   );
 
   if (hasConflict) {
-    const err = new Error("EADDRINUSE");
+    const err = new Error("EADDRINUSE") as NodeJS.ErrnoException;
     err.code = "EADDRINUSE";
     throw err;
   }
 
-  await new Promise((resolve, reject) => {
+  await new Promise<void>((resolve, reject) => {
     let code;
     if (family === "ipv6") {
       code = handle.bind6(address, port, TCPConstants.UV_TCP_IPV6ONLY);
@@ -89,7 +89,7 @@ async function handleTcpBind({ socketId, localAddress }) {
     }
   });
 
-  const out = {};
+  const out: any = {};
   const code = handle.getsockname(out);
   if (code !== 0) {
     throw SocketError.from(-code);
@@ -107,7 +107,7 @@ async function handleTcpConnect({ socketId, remoteAddress }) {
     handle: socket.handle,
     pauseOnCreate: true,
     allowHalfOpen: true,
-  }));
+  } as any));
 
   const onConnect = once(tcp, "connect");
   const onError = once(tcp, "error").then(([err]) => {
@@ -148,7 +148,7 @@ async function handleTcpListen({ socketId, stream }) {
     conn.allowHalfOpen = true;
     const id = NEXT_SOCKET_ID++;
     sockets.set(id, {
-      handle: conn._handle,
+      handle: (conn as any)._handle,
       family,
       backlog,
       tcp: conn,
@@ -188,7 +188,7 @@ async function handleTcpReceive({ socketId, stream }) {
   const { tcp } = socket;
 
   try {
-    await new Promise((resolve, reject) => {
+    await new Promise<void>((resolve, reject) => {
       let settled = false;
       let pending = Promise.resolve();
 
@@ -197,7 +197,7 @@ async function handleTcpReceive({ socketId, stream }) {
         tcp.off("end", onEnd);
         tcp.off("error", onError);
       };
-      const settle = (err) => {
+      const settle = (err = null) => {
         if (settled) {
           return;
         }
@@ -276,11 +276,11 @@ function cleanupDisposedSocket(socketId, socket) {
 
 async function handleGetLocalAddress({ socketId }) {
   const socket = sockets.get(socketId);
-  const out = {};
+  const out: any = {};
 
   const code = socket.handle.getsockname(out);
   if (code !== 0) {
-    throw new SocketError.from(-code);
+    throw SocketError.from(-code);
   }
 
   return makeIpAddress(out.family.toLowerCase(), out.address, out.port);
@@ -288,11 +288,11 @@ async function handleGetLocalAddress({ socketId }) {
 
 async function handleGetRemoteAddress({ socketId }) {
   const socket = sockets.get(socketId);
-  const out = {};
+  const out: any = {};
 
   const code = socket.handle.getpeername(out);
   if (code !== 0) {
-    throw new SocketError.from(-code);
+    throw SocketError.from(-code);
   }
 
   return makeIpAddress(out.family.toLowerCase(), out.address, out.port);
@@ -309,7 +309,7 @@ async function handleTcpSetKeepAlive({ socketId, keepAliveEnabled, keepAliveIdle
 
   const code = socket.handle.setKeepAlive(keepAliveEnabled, time);
   if (code !== 0) {
-    throw mapErrorCode(-code);
+    throw SocketError.from(-code);
   }
 }
 
@@ -344,9 +344,9 @@ function handleTcpDispose({ socketId }) {
 
 let _recvBufferSize, _sendBufferSize;
 async function getDefaultBufferSizes() {
-  var s = new Socket();
+  var s: any = new Socket();
   s.bind(0);
-  await new Promise((resolve, reject) => {
+  await new Promise<void>((resolve, reject) => {
     s.once("error", reject);
     s.once("listening", resolve);
   });
diff --git a/packages/preview3-shim/lib/nodejs/workers/udp-worker.js b/packages/preview3-shim/src/nodejs/workers/udp-worker.ts
similarity index 94%
rename from packages/preview3-shim/lib/nodejs/workers/udp-worker.js
rename to packages/preview3-shim/src/nodejs/workers/udp-worker.ts
index 96adf6644..7d472f298 100644
--- a/packages/preview3-shim/lib/nodejs/workers/udp-worker.js
+++ b/packages/preview3-shim/src/nodejs/workers/udp-worker.ts
@@ -10,7 +10,7 @@ import {
 
 import dgram from "node:dgram";
 
-const sockets = new Map();
+const sockets = new Map<any, any>();
 // Unique IDs for sockets
 let NEXT_SOCKET_ID = 0n;
 
@@ -38,7 +38,7 @@ Router()
 
 function handleCreate({ family }) {
   const socketId = NEXT_SOCKET_ID++;
-  const socket = {
+  const socket: any = {
     family,
     connected: null,
     localAddress: null,
@@ -73,7 +73,7 @@ async function handleBind({ socketId, localAddress }) {
   );
 
   if (hasConflict) {
-    const err = new Error("EADDRINUSE");
+    const err = new Error("EADDRINUSE") as NodeJS.ErrnoException;
     err.code = "EADDRINUSE";
     throw err;
   }
@@ -103,7 +103,7 @@ async function handleConnect({ socketId, remoteAddress }) {
 
   if (socket.connected) {
     const localAddress = preserveLocalAddress ? socket.localAddress : null;
-    await new Promise((resolve) => socket.udp.close(resolve));
+    await new Promise<void>((resolve) => socket.udp.close(resolve));
     socket.udp = createSocket(socket);
     if (localAddress) {
       await handleBind({ socketId, localAddress });
@@ -115,7 +115,7 @@ async function handleConnect({ socketId, remoteAddress }) {
   const addr = serializeIpAddress(remoteAddress);
   const port = remoteAddress.val.port;
 
-  await new Promise((resolve, reject) => {
+  await new Promise<void>((resolve, reject) => {
     socket.udp.connect(port, addr, (err) => (err ? reject(err) : resolve()));
   });
   const boundAddr = socket.udp.address();
@@ -133,7 +133,7 @@ async function handleSend({ socketId, data, remoteAddress }) {
   const socket = sockets.get(socketId);
   const isConnected = socket.connected != null;
 
-  await new Promise((resolve, reject) => {
+  await new Promise<void>((resolve, reject) => {
     if (isConnected) {
       socket.udp.send(data, (err) => (err ? reject(err) : resolve()));
     } else {
diff --git a/packages/preview3-shim/test/nop-worker.js b/packages/preview3-shim/test/nop-worker.js
index 0f3ef77cf..929eaceee 100644
--- a/packages/preview3-shim/test/nop-worker.js
+++ b/packages/preview3-shim/test/nop-worker.js
@@ -1,4 +1,4 @@
-import { Router } from "../lib/nodejs/workers/resource-worker.js";
+import { Router } from "../dist/nodejs/workers/resource-worker.js";
 
 Router()
   .op("nop", () => {
diff --git a/packages/preview3-shim/test/resource-worker.bench.js b/packages/preview3-shim/test/resource-worker.bench.js
index 724a31628..9c9a5440c 100644
--- a/packages/preview3-shim/test/resource-worker.bench.js
+++ b/packages/preview3-shim/test/resource-worker.bench.js
@@ -1,5 +1,5 @@
 import { describe, bench } from "vitest";
-import { ResourceWorker } from "../lib/nodejs/workers/resource-worker.js";
+import { ResourceWorker } from "../dist/nodejs/workers/resource-worker.js";
 
 const _worker = new ResourceWorker(new URL("./nop-worker.js", import.meta.url));
 
diff --git a/packages/preview3-shim/test/resource-worker.test.js b/packages/preview3-shim/test/resource-worker.test.js
index 3a5f7f416..4673dde64 100644
--- a/packages/preview3-shim/test/resource-worker.test.js
+++ b/packages/preview3-shim/test/resource-worker.test.js
@@ -1,5 +1,5 @@
 import { describe, test, expect } from "vitest";
-import { ResourceWorker } from "../lib/nodejs/workers/resource-worker.js";
+import { ResourceWorker } from "../dist/nodejs/workers/resource-worker.js";
 
 const _worker = new ResourceWorker(new URL("./nop-worker.js", import.meta.url));
 
diff --git a/packages/preview3-shim/tsconfig.build.json b/packages/preview3-shim/tsconfig.build.json
new file mode 100644
index 000000000..5eec24ca9
--- /dev/null
+++ b/packages/preview3-shim/tsconfig.build.json
@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": ["test/**/*"],
+  "compilerOptions": {
+    "rootDir": "src/",
+    "declaration": true,
+    "declarationMap": false,
+    "sourceMap": false,
+    "noEmit": false
+  }
+}
diff --git a/packages/preview3-shim/tsconfig.json b/packages/preview3-shim/tsconfig.json
new file mode 100644
index 000000000..6caac5bee
--- /dev/null
+++ b/packages/preview3-shim/tsconfig.json
@@ -0,0 +1,21 @@
+{
+  "include": ["src/**/*"],
+  "compilerOptions": {
+    "outDir": "dist",
+    "target": "ES2022",
+    "lib": ["ESNext", "DOM"],
+    "types": ["node"],
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    "strict": true,
+    "noImplicitAny": false,
+    "strictNullChecks": false,
+    "useUnknownInCatchVariables": false,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "noEmit": true
+  }
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index a0fa12f28..2f7a7f7ed 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -405,17 +405,23 @@ importers:
   packages/preview3-shim:
     dependencies:
       '@bytecodealliance/preview2-shim':
-        specifier: ^0.18.1
-        version: 0.18.1
+        specifier: ^0.19.0
+        version: 0.19.0
     devDependencies:
+      '@types/node':
+        specifier: ^24.12.4
+        version: 24.12.4
       globals:
         specifier: ^17.6.0
         version: 17.6.0
+      typescript:
+        specifier: 'catalog:'
+        version: 6.0.3
       vite:
         specifier: ^8.0.16
         version: 8.0.16(@types/node@24.12.4)(esbuild@0.27.7)(jiti@2.6.1)(terser@5.48.0)
       vitest:
-        specifier: ^4.1.0
+        specifier: 'catalog:'
         version: 4.1.6(@types/node@24.12.4)(vite@8.0.16(@types/node@24.12.4)(esbuild@0.27.7)(jiti@2.6.1)(terser@5.48.0))
 
 packages:
@@ -473,6 +479,9 @@ packages:
   '@bytecodealliance/preview2-shim@0.18.1':
     resolution: {integrity: sha512-8+QEByJTHusG1JkYQNUwOZO0ZvP3zQJD7UVYcyRh8OedKfVls1VuPw/HfSuK0ustslzAkGz7uQCkaBbW+fal9w==}
 
+  '@bytecodealliance/preview2-shim@0.19.0':
+    resolution: {integrity: sha512-OSUlcM62fXLuzYP0DjBn/SwjKMZ/y/2PMXZ8v5cRiiFcroauntlPRl/oCnx0xYjYiqdYvE0PY50VCNutll0xOw==}
+
   '@bytecodealliance/preview3-shim@0.1.2':
     resolution: {integrity: sha512-5twfO5h6zVkJ2QLxrLR21qyLS3jY35XvY0f+jZV4e9FkI6qa2RdPfNDgC50HYhGCtWmbH4TlN1puIyHfEemSNg==}
 
@@ -3900,6 +3909,8 @@ snapshots:
 
   '@bytecodealliance/preview2-shim@0.18.1': {}
 
+  '@bytecodealliance/preview2-shim@0.19.0': {}
+
   '@bytecodealliance/preview3-shim@0.1.2':
     dependencies:
       '@bytecodealliance/preview2-shim': 0.17.9
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index ebd7d62b3..86ab30287 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -36,6 +36,7 @@ catalog:
 minimumReleaseAgeExclude:
   - '@bytecodealliance/componentize-js@0.21.0'
   - '@bytecodealliance/jco-transpile@0.3.3'
+  - '@bytecodealliance/preview2-shim@0.19.0'
   - '@bytecodealliance/preview3-shim@0.1.2'
   - '@puppeteer/browsers@3.0.4'
   - puppeteer-core@25.1.0