`bun-wasm` fixes & improvements (#4126)

* automate Bun.version & revision polyfills

* polyfill Bun.gc

* bun:jsc module initial polyfills

* fixes & improvements to bun-wasm

14 files changed, 252 insertions, 44 deletions

diff --git a/.gitignore b/.gitignore
index f5823c788..5d4da2f88 100644
--- a/.gitignore
+++ b/.gitignore
@@ -96,6 +96,8 @@ packages/bun-wasm/*.cjs
 packages/bun-wasm/*.map
 packages/bun-wasm/*.js
 packages/bun-wasm/*.d.ts
+packages/bun-wasm/*.d.cts
+packages/bun-wasm/*.d.mts
 *.bc
 
 src/fallback.version
diff --git a/Makefile b/Makefile
index 070d03ec4..2a04a21e4 100644
--- a/Makefile
+++ b/Makefile
@@ -705,7 +705,7 @@ dev-build-obj-wasm:
 dev-wasm: dev-build-obj-wasm
 	emcc -sEXPORTED_FUNCTIONS="['_bun_free', '_cycleStart', '_cycleEnd', '_bun_malloc', '_scan', '_transform', '_init', '_getTests']" \
 		-g2 -s ERROR_ON_UNDEFINED_SYMBOLS=0  -DNDEBUG  \
-		$(BUN_DEPS_DIR)/libmimalloc.a.wasm  \
+		$(BUN_DEPS_DIR)/$(MIMALLOC_FILE).wasm  \
 		packages/debug-bun-freestanding-wasm32/bun-wasm.o --no-entry --allow-undefined  -s ASSERTIONS=0  -s ALLOW_MEMORY_GROWTH=1 -s WASM_BIGINT=1  \
 		-o packages/debug-bun-freestanding-wasm32/bun-wasm.wasm
 	cp packages/debug-bun-freestanding-wasm32/bun-wasm.wasm packages/bun-wasm/bun.wasm
@@ -715,7 +715,7 @@ build-obj-wasm:
 	$(ZIG) build bun-wasm -Doptimize=ReleaseFast -Dtarget=wasm32-freestanding
 	emcc -sEXPORTED_FUNCTIONS="['_bun_free', '_cycleStart', '_cycleEnd', '_bun_malloc', '_scan', '_transform', '_init', '_getTests']" \
 		-s ERROR_ON_UNDEFINED_SYMBOLS=0  -DNDEBUG  \
-		$(BUN_DEPS_DIR)/libmimalloc.a.wasm  \
+		$(BUN_DEPS_DIR)/$(MIMALLOC_FILE).wasm  \
 		packages/bun-freestanding-wasm32/bun-wasm.o $(OPTIMIZATION_LEVEL) --no-entry --allow-undefined  -s ASSERTIONS=0  -s ALLOW_MEMORY_GROWTH=1 -s WASM_BIGINT=1  \
 		-o packages/bun-freestanding-wasm32/bun-wasm.wasm
 	cp packages/bun-freestanding-wasm32/bun-wasm.wasm packages/bun-wasm/bun.wasm
@@ -725,18 +725,20 @@ build-obj-wasm-small:
 	$(ZIG) build bun-wasm -Doptimize=ReleaseFast -Dtarget=wasm32-freestanding
 	emcc -sEXPORTED_FUNCTIONS="['_bun_free', '_cycleStart', '_cycleEnd', '_bun_malloc', '_scan', '_transform', '_init', '_getTests']" \
 		-Oz -s ERROR_ON_UNDEFINED_SYMBOLS=0  -DNDEBUG  \
-		$(BUN_DEPS_DIR)/libmimalloc.a.wasm  \
+		$(BUN_DEPS_DIR)/$(MIMALLOC_FILE).wasm  \
 		packages/bun-freestanding-wasm32/bun-wasm.o -Oz --no-entry --allow-undefined  -s ASSERTIONS=0  -s ALLOW_MEMORY_GROWTH=1 -s WASM_BIGINT=1  \
 		-o packages/bun-freestanding-wasm32/bun-wasm.wasm
 	cp packages/bun-freestanding-wasm32/bun-wasm.wasm packages/bun-wasm/bun.wasm
 
 .PHONY: wasm
 wasm: api mimalloc-wasm build-obj-wasm-small
-	@rm -rf packages/bun-wasm/*.{d.ts,js,wasm,cjs,mjs,tsbuildinfo}
+	@rm -rf packages/bun-wasm/*.{d.ts,d.cts,d.mts,js,wasm,cjs,mjs,tsbuildinfo}
 	@cp packages/bun-freestanding-wasm32/bun-wasm.wasm packages/bun-wasm/bun.wasm
 	@cp src/api/schema.d.ts packages/bun-wasm/schema.d.ts
 	@cp src/api/schema.js packages/bun-wasm/schema.js
 	@cd packages/bun-wasm && $(NPM_CLIENT) run tsc -- -p .
+	@cp packages/bun-wasm/index.d.ts packages/bun-wasm/index.d.cts
+	@mv packages/bun-wasm/index.d.ts packages/bun-wasm/index.d.mts
 	@bun build --sourcemap=external --external=fs --outdir=packages/bun-wasm --target=browser --minify ./packages/bun-wasm/index.ts
 	@mv packages/bun-wasm/index.js packages/bun-wasm/index.mjs
 	@mv packages/bun-wasm/index.js.map packages/bun-wasm/index.mjs.map
diff --git a/packages/bun-polyfills/package.json b/packages/bun-polyfills/package.json
index e1852eddc..f08452c3d 100644
--- a/packages/bun-polyfills/package.json
+++ b/packages/bun-polyfills/package.json
@@ -14,7 +14,8 @@
   "scripts": {
     "node": "node --enable-source-maps --import ./dist/src/repl.js",
     "clean": "rm -rf dist",
-    "build": "bun run clean && bunx tsc && bunx copyfiles \"./**/*.wasm\" dist",
+    "preprocess": "bun tools/updateversions.ts",
+    "build": "bun run clean && bun run preprocess && bunx tsc && bunx copyfiles \"./**/*.wasm\" dist",
     "build/wasm": "bun run build/zighash",
     "build/zighash": "cd lib/zighash && bun run build && cd ../.."
   },
diff --git a/packages/bun-polyfills/src/modules/bun.ts b/packages/bun-polyfills/src/modules/bun.ts
index ce0f6f6be..432daea95 100644
--- a/packages/bun-polyfills/src/modules/bun.ts
+++ b/packages/bun-polyfills/src/modules/bun.ts
@@ -30,8 +30,16 @@ import openEditor from 'open-editor';
 

 export const main = path.resolve(process.cwd(), process.argv[1] ?? 'repl') satisfies typeof Bun.main;

 

-export const version = '0.7.1' satisfies typeof Bun.version; // TODO: This can probably be fetched from somewhere in the repo

-export const revision = '0'.repeat(39) + '1' satisfies typeof Bun.revision;

+//? These are automatically updated on build by tools/updateversions.ts, do not edit manually.

+export const version = '0.7.4' satisfies typeof Bun.version;

+export const revision = '7088d7e182635a58a50860302da0b1abc42c7ce7' satisfies typeof Bun.revision;

+

+export const gc = (globalThis.gc ? (() => (globalThis.gc!(), process.memoryUsage().heapUsed)) : (() => {

+    const err = new Error('[bun-polyfills] Garbage collection polyfills are only available when Node.js is ran with the --expose-gc flag.');

+    Error.captureStackTrace(err, gc);

+    throw err;

+})) satisfies typeof Bun.gc;

+

 //getter(bun, 'cwd', proc.cwd); //! Can't named export a getter

 export const origin = '' satisfies typeof Bun.origin;

 // @ts-expect-error ---

diff --git a/packages/bun-polyfills/src/modules/jsc.ts b/packages/bun-polyfills/src/modules/jsc.ts
new file mode 100644
index 000000000..45062d339
--- /dev/null
+++ b/packages/bun-polyfills/src/modules/jsc.ts
@@ -0,0 +1,111 @@
+import type jsc from 'bun:jsc';
+import v8 from 'node:v8';
+//import { setRandomSeed, getRandomSeed } from './mathrandom.js';
+import { NotImplementedError, getCallSites } from '../utils/errors.js';
+import { gc } from './bun.js';
+
+const STUB = () => void 0;
+
+function jscSerialize(value: any, options?: { binaryType: 'nodebuffer'; }): Buffer;
+function jscSerialize(value: any, options?: { binaryType?: 'arraybuffer'; }): SharedArrayBuffer;
+function jscSerialize(value: any, options?: { binaryType?: string }): Buffer | SharedArrayBuffer {
+    const serialized = v8.serialize(value);
+    if (options?.binaryType === 'nodebuffer') return serialized;
+    else return new SharedArrayBuffer(serialized.byteLength);
+}
+// TODO: Investigate ways of making these the actual JSC serialization format (probably Bun WASM)
+// TODO: whilst this works for common use-cases like Node <-> Node it still does not make it
+// TODO: possible for Node <-> Bun transfers of this kind of data, which might be interesting to have.
+export const serialize = jscSerialize satisfies typeof jsc.serialize;
+export const deserialize = (value => {
+    if (value instanceof ArrayBuffer || value instanceof SharedArrayBuffer) return v8.deserialize(Buffer.from(value));
+    else return v8.deserialize(value);
+}) satisfies typeof jsc.deserialize;
+
+export const setTimeZone = ((timeZone: string) => {
+    const resolvedTZ = Intl.DateTimeFormat(undefined, { timeZone }).resolvedOptions().timeZone;
+    return process.env.TZ = resolvedTZ;
+}) satisfies typeof jsc.setTimeZone;
+
+export const callerSourceOrigin = (() => {
+    const callsites: NodeJS.CallSite[] = getCallSites(2);
+    // This may be inaccurate with async code. Needs more testing.
+    let lastSeenURL = '';
+    for (const callsite of callsites) {
+        const sourceURL = callsite.getScriptNameOrSourceURL();
+        if (sourceURL.startsWith('file://')) lastSeenURL = sourceURL;
+    }
+    return lastSeenURL;
+}) satisfies typeof jsc.callerSourceOrigin;
+
+// TODO: Like with jsc.serialize/deserialize, these may be possible with Bun WASM.
+export const jscDescribe = (() => { throw new NotImplementedError('jsc.jscDescribe', STUB); }) satisfies typeof jsc.jscDescribe;
+export const jscDescribeArray = (() => { throw new NotImplementedError('jsc.jscDescribeArray', STUB); }) satisfies typeof jsc.jscDescribeArray;
+// These are no longer documented but still exist.
+export const describe = jscDescribe;
+export const describeArray = jscDescribeArray;
+
+// Node.js only provides a singular non-configurable global GC function, so we have to make do with that.
+export const edenGC = gc satisfies typeof jsc.edenGC;
+export const fullGC = gc satisfies typeof jsc.fullGC;
+export const gcAndSweep = gc satisfies typeof jsc.gcAndSweep;
+
+export const drainMicrotasks = STUB satisfies typeof jsc.drainMicrotasks; // no-op
+export const releaseWeakRefs = STUB satisfies typeof jsc.releaseWeakRefs; // no-op
+export const startSamplingProfiler = STUB satisfies typeof jsc.startSamplingProfiler; // no-op
+//! likely broken but needs more testing
+export const startRemoteDebugger = STUB satisfies typeof jsc.startRemoteDebugger; // no-op
+
+//! this is a really poor polyfill but it's better than nothing
+export const getProtectedObjects = (() => { return [globalThis]; }) satisfies typeof jsc.getProtectedObjects;
+
+export const getRandomSeed = 0; // TODO
+export const setRandomSeed = 0; // TODO
+
+export const heapSize = (() => { return v8.getHeapStatistics().used_heap_size; }) satisfies typeof jsc.heapSize;
+export const heapStats = (() => {
+    const stats = v8.getHeapStatistics();
+    return {
+        heapSize: stats.used_heap_size,
+        heapCapacity: stats.total_available_size,
+        extraMemorySize: stats.external_memory ?? 0,
+        objectCount: 1, // TODO: how to get this in node?
+        protectedObjectCount: getProtectedObjects().length,
+        globalObjectCount: 2, // TODO: this one is probably fine hardcoded but is there a way to get this in node?
+        protectedGlobalObjectCount: 1, // TODO: ^
+        objectTypeCounts: {}, //! can't really throw an error here, so just return an empty object (TODO: how to get this in node?)
+        protectedObjectTypeCounts: {} //! can't really throw an error here, so just return an empty object (TODO: how to get this in node?)
+    };
+}) satisfies typeof jsc.heapStats;
+
+//! doubtful anyone relies on the return of this for anything besides debugging
+export const isRope = (() => false) satisfies typeof jsc.isRope;
+
+export const memoryUsage = (() => {
+    const stats = v8.getHeapStatistics();
+    const resUse = process.resourceUsage();
+    return {
+        current: stats.malloced_memory,
+        peak: stats.peak_malloced_memory,
+        currentCommit: stats.malloced_memory,
+        peakCommit: stats.malloced_memory,
+        pageFaults: resUse.minorPageFault + resUse.majorPageFault
+    };
+}) satisfies typeof jsc.memoryUsage;
+
+//! these are likely broken, seemingly always returning undefined which does not match the documented return types
+export const noFTL = (() => { return void 0 as unknown as Function; }) satisfies typeof jsc.noFTL;
+export const noOSRExitFuzzing = (() => { return void 0 as unknown as Function; }) satisfies typeof jsc.noOSRExitFuzzing;
+//! likely broken, seems to always returns zero
+export const totalCompileTime = (() => 0) satisfies typeof jsc.totalCompileTime;
+//! likely broken, seem to always returns 0 if any arguments are passed, undefined otherwise
+export const numberOfDFGCompiles = ((...args) => args.length ? 0 : void 0 as unknown as number) satisfies typeof jsc.numberOfDFGCompiles;
+export const reoptimizationRetryCount = ((...args) => args.length ? 0 : void 0 as unknown as number) satisfies typeof jsc.reoptimizationRetryCount;
+
+//! The following are very likely impossible to ever polyfill.
+export const profile = (() => {
+    throw new NotImplementedError('jsc.profile is not polyfillable', STUB, true);
+}) satisfies typeof jsc.profile;
+export const optimizeNextInvocation = (() => {
+    throw new NotImplementedError('jsc.optimizeNextInvocation is not polyfillable', STUB, true);
+}) satisfies typeof jsc.optimizeNextInvocation;
diff --git a/packages/bun-polyfills/src/repl.ts b/packages/bun-polyfills/src/repl.ts
index 5cf673701..030e479b0 100644
--- a/packages/bun-polyfills/src/repl.ts
+++ b/packages/bun-polyfills/src/repl.ts
@@ -1,4 +1,5 @@
 import bun from './index.js';
+import * as jsc from './modules/jsc.js';
 
 // This file serves two purposes:
 // 1. It is the entry point for using the Bun global in the REPL. (--import this file)
@@ -12,7 +13,6 @@ globalThis.Bun = bun as typeof bun & {
     deepMatch: typeof import('bun').deepMatch;
     build: typeof import('bun').build;
     mmap: typeof import('bun').mmap;
-    gc: typeof import('bun').gc;
     connect: typeof import('bun').connect;
     listen: typeof import('bun').listen;
     Transpiler: typeof import('bun').Transpiler;
@@ -27,3 +27,5 @@ globalThis.Bun = bun as typeof bun & {
     stderr: typeof import('bun').stderr;
     stdin: typeof import('bun').stdin;
 };
+
+Reflect.set(globalThis, 'jsc', jsc);
diff --git a/packages/bun-polyfills/src/types/sync.d.ts b/packages/bun-polyfills/src/types/sync.d.ts
index 87e6794e0..11ed63a17 100644
--- a/packages/bun-polyfills/src/types/sync.d.ts
+++ b/packages/bun-polyfills/src/types/sync.d.ts
@@ -12,4 +12,19 @@ declare module 'stream/web' {
 
 declare global {
     var performance: typeof import('perf_hooks').performance;
+
+    // TODO: These should be contributed to @types/node upstream
+    namespace NodeJS {
+        interface CallSite {
+            getScriptNameOrSourceURL(): string;
+            getEnclosingColumnNumber(): number;
+            getEnclosingLineNumber(): number;
+            getPosition(): number;
+            getPromiseIndex(): number;
+            getScriptHash(): string;
+            isAsync(): boolean;
+            isPromiseAll(): boolean;
+            toString(): string;
+        }
+    }
 }
diff --git a/packages/bun-polyfills/src/utils/errors.ts b/packages/bun-polyfills/src/utils/errors.ts
index cc82efdf0..35b967436 100644
--- a/packages/bun-polyfills/src/utils/errors.ts
+++ b/packages/bun-polyfills/src/utils/errors.ts
@@ -1,6 +1,15 @@
 type PosixErrNo = MapKeysType<ReturnType<typeof getPosixSystemErrorMap>>;

 type Win32ErrNo = MapKeysType<ReturnType<typeof getWin32SystemErrorMap>>;

 

+export function getCallSites(sliceOff = 1) {

+    const originalPST = Error.prepareStackTrace;

+    Error.prepareStackTrace = (error, stack) => stack;

+    const { stack } = new Error();

+    if (stack?.constructor.name !== 'Array') throw new Error('Failed to acquire structured JS stack trace');

+    Error.prepareStackTrace = originalPST;

+    return (stack as unknown as NodeJS.CallSite[]).slice(sliceOff);

+}

+

 export function getPosixSystemErrorMap() {

     return new Map([

         [ -7, [ 'E2BIG', 'argument list too long' ] ],

diff --git a/packages/bun-polyfills/tools/updateversions.ts b/packages/bun-polyfills/tools/updateversions.ts
new file mode 100644
index 000000000..bf838ac55
--- /dev/null
+++ b/packages/bun-polyfills/tools/updateversions.ts
@@ -0,0 +1,41 @@
+import path from 'path';
+
+const abort = (...msg: string[]): never => (console.error(...msg), process.exit(1));
+
+const makefilePath = path.resolve(import.meta.dir, '../../../Makefile');
+const makefile = Bun.file(makefilePath);
+if (!await makefile.exists()) abort('Makefile not found at', makefilePath);
+
+const makefileContent = await makefile.text();
+const matched = makefileContent.match(/^BUN_BASE_VERSION\s*=\s*(\d+.\d+)/m);
+if (!matched) abort('Could not find BUN_BASE_VERSION in Makefile');
+
+const buildidPath = path.resolve(import.meta.dir, '../../../src/build-id');
+const buildid = Bun.file(buildidPath);
+if (!await buildid.exists()) abort('Build ID file not found at', buildidPath);
+
+const [, BUN_BASE_VERSION] = matched!;
+const BUN_VERSION = `${BUN_BASE_VERSION}.${await buildid.text()}`.trim();
+
+const bunTsPath = path.resolve(import.meta.dir, '../src/modules/bun.ts');
+const bunTs = Bun.file(bunTsPath);
+if (!await bunTs.exists()) abort('bun.ts source file not found at', bunTsPath);
+
+const bunTsContent = await bunTs.text();
+const bunTsContentNew = bunTsContent.replace(
+    /^export const version = '.+' satisfies typeof Bun.version;$/m,
+    `export const version = '${BUN_VERSION}' satisfies typeof Bun.version;`
+);
+if (bunTsContentNew !== bunTsContent) console.info('Updated Bun.version polyfill to', BUN_VERSION);
+
+const git = Bun.spawnSync({ cmd: ['git', 'rev-parse', 'HEAD'] });
+if (!git.success) abort('Could not get git HEAD commit hash');
+const BUN_REVISION = git.stdout.toString('utf8').trim();
+
+const bunTsContentNewer = bunTsContentNew.replace(
+    /^export const revision = '.+' satisfies typeof Bun.revision;$/m,
+    `export const revision = '${BUN_REVISION}' satisfies typeof Bun.revision;`
+);
+if (bunTsContentNewer !== bunTsContentNew) console.info('Updated Bun.revision polyfill to', BUN_REVISION);
+
+Bun.write(bunTs, bunTsContentNewer);
diff --git a/packages/bun-wasm/bun.lockb b/packages/bun-wasm/bun.lockb
index fdaf01b1f..d77107312 100755
--- a/packages/bun-wasm/bun.lockb
+++ b/packages/bun-wasm/bun.lockb
diff --git a/packages/bun-wasm/index.ts b/packages/bun-wasm/index.ts
index 10a7b3aa4..72eed5220 100644
--- a/packages/bun-wasm/index.ts
+++ b/packages/bun-wasm/index.ts
@@ -1,4 +1,3 @@
-// @ts-nocheck
 import { ByteBuffer } from "peechy/bb";
 import {
   Loader as BunLoader,
@@ -12,20 +11,28 @@ import {
   type ScanResult,
   type TransformResponse,
 } from "./schema";
+
 export enum Loader {
   jsx = BunLoader.jsx,
   js = BunLoader.js,
   tsx = BunLoader.tsx,
   ts = BunLoader.ts,
 }
+export interface TestReference {
+  name: string,
+  byteOffset: number,
+  kind: 'test' | 'describe',
+}
+export type { ScanResult, TransformResponse };
+
 const testKindMap = {
   [TestKind.describe_fn]: "describe",
   [TestKind.test_fn]: "test",
 };
-const capturedErrors = [];
+const capturedErrors: string[] = [];
 let captureErrors = false;
-export type { ScanResult, TransformResponse };
-function normalizeLoader(file_name: string, loader?: Loader): BunLoader {
+
+function normalizeLoader(file_name: string, loader?: keyof typeof Loader): BunLoader {
   return (
     (loader
       ? {
@@ -46,11 +53,12 @@ function normalizeLoader(file_name: string, loader?: Loader): BunLoader {
 }
 
 interface WebAssemblyModule {
-  init(): number;
+  init(heapSize: number): number;
   transform(a: number): number;
   bun_malloc(a: number): number;
   bun_free(a: number): number;
   scan(a: number): number;
+  getTests(a: number): number;
 }
 
 const ptr_converter = new ArrayBuffer(16);
@@ -58,28 +66,28 @@ const ptr_float = new BigUint64Array(ptr_converter);
 const slice = new Uint32Array(ptr_converter);
 
 const Wasi = {
-  clock_time_get(clk_id, tp) {
+  clock_time_get(clk_id: unknown, tp: unknown) {
     return Date.now();
   },
   environ_sizes_get() {
     debugger;
     return 0;
   },
-  environ_get(__environ, environ_buf) {
+  environ_get(__environ: unknown, environ_buf: unknown) {
     debugger;
     return 0;
   },
 
-  fd_close(fd) {
+  fd_close(fd: number) {
     debugger;
     return 0;
   },
   proc_exit() {},
 
-  fd_seek(fd, offset_bigint, whence, newOffset) {
+  fd_seek(fd: number, offset_bigint: bigint, whence: unknown, newOffset: unknown) {
     debugger;
   },
-  fd_write(fd, iov, iovcnt, pnum) {
+  fd_write(fd: unknown, iov: unknown, iovcnt: unknown, pnum: unknown) {
     debugger;
   },
 };
@@ -89,16 +97,16 @@ var scratch2: Uint8Array;
 
 const env = {
   console_log(slice: number) {
+    // @ts-expect-error
     const text = Bun._wasmPtrLenToString(slice);
     if (captureErrors) {
       capturedErrors.push(text);
       return;
     }
-    //@ts-ignore
     console.log(text);
   },
   console_error(slice: number) {
-    //@ts-ignore
+    // @ts-expect-error
     const text = Bun._wasmPtrLenToString(slice);
     if (captureErrors) {
       capturedErrors.push(text);
@@ -107,19 +115,17 @@ const env = {
     console.error(text);
   },
   console_warn(slice: number) {
-    //@ts-ignore
+    // @ts-expect-error
     console.warn(Bun._wasmPtrLenToString(slice));
   },
   console_info(slice: number) {
-    //@ts-ignore
+    // @ts-expect-error
     console.info(Bun._wasmPtrLenToString(slice));
   },
-  // @ts-ignore-line
   __indirect_function_table: new WebAssembly.Table({
     initial: 0,
     element: "anyfunc",
   }),
-  // @ts-ignore-line
   __stack_pointer: new WebAssembly.Global({
     mutable: true,
     value: "i32",
@@ -131,11 +137,11 @@ const env = {
     return one % two;
   },
   memset(ptr: number, value: number, len: number) {
-    //@ts-ignore
+    // @ts-expect-error
     Bun.memory_array.fill(value, ptr, ptr + len);
   },
   memcpy(ptr: number, value: number, len: number) {
-    //@ts-ignore
+    // @ts-expect-error
     Bun.memory_array.copyWithin(ptr, value, value + len);
   },
   // These functions convert a to an unsigned long long, rounding toward zero. Negative values all become zero.
@@ -167,14 +173,13 @@ const env = {
 };
 export class Bun {
   private static has_initialized = false;
-  // @ts-ignore-line
-  private static wasm_source: WebAssembly.WebAssemblyInstantiatedSource = null;
+  private static wasm_source: WebAssembly.WebAssemblyInstantiatedSource;
   private static get wasm_exports(): WebAssemblyModule {
-    return Bun.wasm_source.instance.exports as any;
+    return Bun.wasm_source.instance.exports as unknown as WebAssemblyModule;
   }
-  // @ts-ignore-line
+
   private static get memory(): WebAssembly.Memory {
-    return Bun.wasm_source.instance.exports.memory as any;
+    return Bun.wasm_source.instance.exports.memory as WebAssembly.Memory;
   }
 
   private static memory_array: Uint8Array;
@@ -195,7 +200,8 @@ export class Bun {
     return Bun._decoder.decode(region);
   }
 
-  static async init(url, heapSize = 64_000_000, fetch = globalThis.fetch) {
+  static async init(url?: URL | string | null, heapSize = 64_000_000, fetch = globalThis.fetch) {
+    url ??= new URL("./bun.wasm", import.meta.url);
     scratch = new Uint8Array(8096);
 
     if (Bun.has_initialized) {
@@ -216,9 +222,12 @@ export class Bun {
         // is it node?
       }
     } else {
-      //@ts-ignore
       const fs = await import("fs");
 
+      if (typeof url === 'string' && url.startsWith('file://')) {
+        url = new URL(url); // fs.readFileSync cannot consume URL strings, only URL objects
+      }
+
       Bun.wasm_source = await globalThis.WebAssembly.instantiate(fs.readFileSync(url), {
         env: env,
         wasi_snapshot_preview1: Wasi,
@@ -234,7 +243,7 @@ export class Bun {
     Bun.has_initialized = true;
   }
 
-  static getTests(content: Uint8Array | string, filename = "my.test.tsx") {
+  static getTests(content: Uint8Array, filename = "my.test.tsx") {
     const bb = new ByteBuffer(scratch);
     bb.length = 0;
     bb.index = 0;
@@ -283,7 +292,7 @@ export class Bun {
     var _bb = new ByteBuffer(Bun._wasmPtrToSlice(resp_ptr));
 
     const response = decodeGetTestsResponse(_bb);
-    var tests = new Array(response.tests.length);
+    var tests: TestReference[] = new Array(response.tests.length);
 
     for (var i = 0; i < response.tests.length; i++) {
       tests[i] = {
@@ -294,7 +303,7 @@ export class Bun {
           ),
         ),
         byteOffset: response.tests[i].byteOffset,
-        kind: testKindMap[response.tests[i].kind],
+        kind: testKindMap[response.tests[i].kind] as 'test' | 'describe',
       };
     }
 
@@ -303,7 +312,7 @@ export class Bun {
     return tests;
   }
 
-  static transformSync(content: Uint8Array | string, file_name: string, loader?: Loader): TransformResponse {
+  static transformSync(content: Uint8Array | string, file_name: string, loader?: keyof typeof Loader): TransformResponse {
     const bb = new ByteBuffer(scratch);
     bb.length = 0;
     bb.index = 0;
@@ -330,7 +339,6 @@ export class Bun {
       {
         contents: contents_buffer,
         path: file_name,
-        // @ts-ignore
         loader: normalizeLoader(file_name, loader),
       },
       bb,
@@ -349,7 +357,7 @@ export class Bun {
     return response;
   }
 
-  static scan(content: Uint8Array | string, file_name: string, loader?: Loader): ScanResult {
+  static scan(content: Uint8Array | string, file_name: string, loader?: keyof typeof Loader): ScanResult {
     const bb = new ByteBuffer(scratch);
     bb.length = 0;
     bb.index = 0;
@@ -368,7 +376,6 @@ export class Bun {
       {
         contents: contents_buffer,
         path: file_name,
-        // @ts-ignore
         loader: normalizeLoader(file_name, loader),
       },
       bb,
diff --git a/packages/bun-wasm/package.json b/packages/bun-wasm/package.json
index 5f3234e40..54eb646fa 100644
--- a/packages/bun-wasm/package.json
+++ b/packages/bun-wasm/package.json
@@ -1,7 +1,12 @@
 {
   "name": "bun-wasm",
   "version": "0.0.79",
+  "scripts": {
+    "build": "cd ../.. && make wasm",
+    "dev": "cd ../.. && make dev-wasm"
+  },
   "devDependencies": {
+    "@types/node": "^20.4.10",
     "peechy": "0.4.32",
     "typescript": "latest"
   },
@@ -16,7 +21,7 @@
     "schema.js"
   ],
   "type": "module",
-  "types": "index.d.ts",
+  "types": "index.d.mts",
   "exports": {
     ".": {
       "import": "./index.mjs",
diff --git a/packages/bun-wasm/test/node.mjs b/packages/bun-wasm/test/node.mjs
index 2699a1dad..9c2f503d4 100644
--- a/packages/bun-wasm/test/node.mjs
+++ b/packages/bun-wasm/test/node.mjs
@@ -1,7 +1,10 @@
 import { readFileSync } from "fs";
 import { init, getTests } from "../index.mjs";
 
-const buf = (process.argv.length > 2 ? readFileSync(process.argv.at(-1)) : "") || readFileSync(import.meta.url);
-await init(new URL("../bun.wasm", import.meta.url));
+const filePath = process.argv[2];
+if (!filePath) throw new Error("Usage: node node.mjs <file>");
+
+const buf = readFileSync(filePath);
+await init();
 
 console.log(getTests(buf));
diff --git a/packages/bun-wasm/tsconfig.json b/packages/bun-wasm/tsconfig.json
index cb966c684..9b5b9eb0c 100644
--- a/packages/bun-wasm/tsconfig.json
+++ b/packages/bun-wasm/tsconfig.json
@@ -8,8 +8,10 @@
     "isolatedModules": false,
     "skipLibCheck": true,
     "emitDeclarationOnly": true,
+    "strict": true,
     "outDir": ".",
-    "baseUrl": "."
+    "baseUrl": ".",
+    "types": ["node"]
   },
   "include": [
     "./node_modules/peechy",