Use @bjorn3/browser_wasi_shim as WASI implementation

Author: kateinoigakukun

entrypoint/common.ts

@@ -12,9 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import { WASI } from "@wasmer/wasi";
-import { WasmFs } from "@wasmer/wasmfs";
-import * as path from "path-browserify";
+import { WASI, File, OpenFile, ConsoleStdout, PreopenDirectory } from "@bjorn3/browser_wasi_shim";
 import type { SwiftRuntime, SwiftRuntimeConstructor } from "./JavaScriptKit_JavaScriptKit.resources/Runtime";
 
 export type Options = {
@@ -35,38 +33,29 @@ export const WasmRunner = (rawOptions: Options | false, SwiftRuntime: SwiftRunti
     swift = new SwiftRuntime();
   }
 
-  const wasmFs = createWasmFS(
-    (stdout) => {
+  const args = options.args || [];
+  const fds = [
+    new OpenFile(new File([])), // stdin
+    ConsoleStdout.lineBuffered((stdout) => {
       console.log(stdout);
       options.onStdout?.call(undefined, stdout);
-    },
-    (stderr) => {
+    }),
+    ConsoleStdout.lineBuffered((stderr) => {
       console.error(stderr);
       options.onStderr?.call(undefined, stderr);
-    }
-  );
-
-  wasmFs.fs.mkdirSync("/sandbox");
+    }),
+    new PreopenDirectory("/", new Map()),
+  ];
 
-  const wasi = new WASI({
-    args: options.args,
-    env: {},
-    preopenDirectories: {
-      "/": "/sandbox",
-    },
-    bindings: {
-      ...WASI.defaultBindings,
-      fs: wasmFs.fs,
-      path: path,
-    },
+  const wasi = new WASI(args, [], fds, {
+    debug: false
   });
 
   const createWasmImportObject = (
     extraWasmImports: WebAssembly.Imports,
-    wasmModule: WebAssembly.Module
   ): WebAssembly.Imports => {
     const importObject: WebAssembly.Imports = {
-      wasi_snapshot_preview1: wrapWASI(wasi, wasmModule),
+      wasi_snapshot_preview1: wasi.wasiImport,
     };
 
     if (swift) {
@@ -94,19 +83,19 @@ export const WasmRunner = (rawOptions: Options | false, SwiftRuntime: SwiftRunti
         },
       };
       const module = await WebAssembly.compile(wasmBytes);
-      const importObject = createWasmImportObject(extraWasmImports, module);
+      const importObject = createWasmImportObject(extraWasmImports);
       const instance = await WebAssembly.instantiate(module, importObject);
 
       if (swift && instance.exports.swjs_library_version) {
         swift.setInstance(instance);
       }
 
-      // Start the WebAssembly WASI instance
-      wasi.start(instance);
-
-      // Initialize and start Reactor
-      if (typeof instance.exports._initialize == "function") {
-        instance.exports._initialize();
+      if (typeof instance.exports._start === "function") {
+        // Start the WebAssembly WASI instance
+        wasi.start(instance as any);
+      } else if (typeof instance.exports._initialize == "function") {
+        // Initialize and start Reactor
+        wasi.initialize(instance as any);
         if (typeof instance.exports.main === "function") {
           instance.exports.main();
         } else if (typeof instance.exports.__main_argc_argv === "function") {
@@ -131,73 +120,3 @@ const defaultRunnerOptions = (options: Options | false): Options => {
   }
   return options;
 };
-
-const createWasmFS = (
-  onStdout: (text: string) => void,
-  onStderr: (text: string) => void
-): WasmFs => {
-  // Instantiate a new WASI Instance
-  const wasmFs = new WasmFs();
-
-  // Output stdout and stderr to console
-  const originalWriteSync = wasmFs.fs.writeSync;
-  (wasmFs.fs as any).writeSync = (
-    fd: number, buffer: Buffer | Uint8Array,
-    offset?: number, length?: number, position?: number
-  ): number => {
-    const text = new TextDecoder("utf-8").decode(buffer);
-    if (text !== "\n") {
-      switch (fd) {
-        case 1:
-          onStdout(text);
-          break;
-        case 2:
-          onStderr(text);
-          break;
-      }
-    }
-    return originalWriteSync(fd, buffer, offset, length, position);
-  };
-
-  return wasmFs;
-};
-
-const wrapWASI = (wasiObject: WASI, wasmModule: WebAssembly.Module): WebAssembly.ModuleImports => {
-  // PATCH: @wasmer-js/wasi@0.x forgets to call `refreshMemory` in `clock_res_get`,
-  // which writes its result to memory view. Without the refresh the memory view,
-  // it accesses a detached array buffer if the memory is grown by malloc.
-  // But they wasmer team discarded the 0.x codebase at all and replaced it with
-  // a new implementation written in Rust. The new version 1.x is really unstable
-  // and not production-ready as far as katei investigated in Apr 2022.
-  // So override the broken implementation of `clock_res_get` here instead of
-  // fixing the wasi polyfill.
-  // Reference: https://github.com/wasmerio/wasmer-js/blob/55fa8c17c56348c312a8bd23c69054b1aa633891/packages/wasi/src/index.ts#L557
-  const original_clock_res_get = wasiObject.wasiImport["clock_res_get"];
-
-  wasiObject.wasiImport["clock_res_get"] = (clockId: number, resolution: number) => {
-    wasiObject.refreshMemory();
-    return original_clock_res_get(clockId, resolution);
-  };
-
-  // @wasmer-js/wasi polyfill does not support all WASI syscalls like `sock_accept`.
-  // So we need to insert a dummy function for unimplemented syscalls.
-  const __WASI_ERRNO_NOTSUP = 58;
-  for (const importEntry of WebAssembly.Module.imports(wasmModule)) {
-    const { module: importModule, name: importName, kind: importKind } = importEntry;
-    // Skip dummy import entries for non-WASI and already implemented syscalls.
-    if (
-      importModule !== "wasi_snapshot_preview1" ||
-      importKind !== "function" ||
-      wasiObject.wasiImport[importName]
-    ) {
-      continue;
-    }
-
-    wasiObject.wasiImport[importName] = () => {
-      console.warn(`WASI syscall ${importModule}.${importName} is not supported, returning ENOTSUP.`);
-      return __WASI_ERRNO_NOTSUP;
-    }
-  }
-
-  return wasiObject.wasiImport;
-};

entrypoint/test.ts

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import ReconnectingWebSocket from "reconnecting-websocket";
-import { WASIExitError } from "@wasmer/wasi";
+import { WASIProcExit } from "@bjorn3/browser_wasi_shim";
 import { WasmRunner } from "./common.js";
 import type { SwiftRuntimeConstructor } from "./JavaScriptKit_JavaScriptKit.resources/Runtime";
 
@@ -73,7 +73,7 @@ const startWasiTask = async () => {
 
   const handleExitOrError = (error: any) => {
     // XCTest always calls `exit` at the end when no crash
-    if (error instanceof WASIExitError) {
+    if (error instanceof WASIProcExit) {
       // pass the output to the server in any case
       socket.send(JSON.stringify({ kind: "testRunOutput", testRunOutput }));
       if (error.code === 0) {