wasi: add support for version when creating WASI

Refs: https://github.com/nodejs/node/issues/46254

- add version to options when creating WASI object
- add convenience function to return importObject

Signed-off-by: Michael Dawson <mdawson@devrus.com>

PR-URL: https://github.com/nodejs/node/pull/46469
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

doc/api/wasi.md

@@ -16,6 +16,7 @@ import { WASI } from 'wasi';
 import { argv, env } from 'node:process';
 
 const wasi = new WASI({
+  version: 'preview1',
   args: argv,
   env,
   preopens: {
@@ -23,14 +24,10 @@ const wasi = new WASI({
   },
 });
 
-// Some WASI binaries require:
-//   const importObject = { wasi_unstable: wasi.wasiImport };
-const importObject = { wasi_snapshot_preview1: wasi.wasiImport };
-
 const wasm = await WebAssembly.compile(
   await readFile(new URL('./demo.wasm', import.meta.url)),
 );
-const instance = await WebAssembly.instantiate(wasm, importObject);
+const instance = await WebAssembly.instantiate(wasm, wasi.getImportObject());
 
 wasi.start(instance);
 ```
@@ -43,6 +40,7 @@ const { argv, env } = require('node:process');
 const { join } = require('node:path');
 
 const wasi = new WASI({
+  version: 'preview1',
   args: argv,
   env,
   preopens: {
@@ -50,15 +48,11 @@ const wasi = new WASI({
   },
 });
 
-// Some WASI binaries require:
-//   const importObject = { wasi_unstable: wasi.wasiImport };
-const importObject = { wasi_snapshot_preview1: wasi.wasiImport };
-
 (async () => {
   const wasm = await WebAssembly.compile(
     await readFile(join(__dirname, 'demo.wasm')),
   );
-  const instance = await WebAssembly.instantiate(wasm, importObject);
+  const instance = await WebAssembly.instantiate(wasm, wasi.getImportObject());
 
   wasi.start(instance);
 })();
@@ -126,6 +120,10 @@ sandbox directory structure configured explicitly.
 added:
  - v13.3.0
  - v12.16.0
+changes:
+ - version: REPLACEME
+   pr-url: https://github.com/nodejs/node/pull/46469
+   description: version field added to options.
 -->
 
 * `options` {Object}
@@ -148,6 +146,30 @@ added:
     WebAssembly application. **Default:** `1`.
   * `stderr` {integer} The file descriptor used as standard error in the
     WebAssembly application. **Default:** `2`.
+  * `version` {string} The version of WASI requested. Currently the only
+    supported versions are `unstable` and `preview1`. **Default:** `preview1`.
+
+### `wasi.getImportObject()`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Return an import object that can be passed to `WebAssembly.instantiate()` if
+no other WASM imports are needed beyond those provided by WASI.
+
+If version `unstable` was passed into the constructor it will return:
+
+```json
+{ wasi_unstable: wasi.wasiImport }
+```
+
+If version `preview1` was passed into the constructor or no version was
+specified it will return:
+
+```json
+{ wasi_snapshot_preview1: wasi.wasiImport }
+```
 
 ### `wasi.start(instance)`
 

lib/wasi.js

@@ -10,6 +10,7 @@ const {
 } = primordials;
 
 const {
+  ERR_INVALID_ARG_VALUE,
   ERR_WASI_ALREADY_STARTED
 } = require('internal/errors').codes;
 const {
@@ -22,13 +23,14 @@ const {
   validateFunction,
   validateInt32,
   validateObject,
+  validateString,
   validateUndefined,
 } = require('internal/validators');
-const { WASI: _WASI } = internalBinding('wasi');
 const kExitCode = Symbol('kExitCode');
 const kSetMemory = Symbol('kSetMemory');
 const kStarted = Symbol('kStarted');
 const kInstance = Symbol('kInstance');
+const kBindingName = Symbol('kBindingName');
 
 emitExperimentalWarning('WASI');
 
@@ -45,6 +47,31 @@ class WASI {
   constructor(options = kEmptyObject) {
     validateObject(options, 'options');
 
+    let _WASI;
+    if (options.version !== undefined) {
+      validateString(options.version, 'options.version');
+      switch (options.version) {
+        case 'unstable':
+          ({ WASI: _WASI } = internalBinding('wasi'));
+          this[kBindingName] = 'wasi_unstable';
+          break;
+        // When adding support for additional wasi versions add case here
+        case 'preview1':
+          ({ WASI: _WASI } = internalBinding('wasi'));
+          this[kBindingName] = 'wasi_snapshot_preview1';
+          break;
+        // When adding support for additional wasi versions add case here
+        default:
+          throw new ERR_INVALID_ARG_VALUE('options.version',
+                                          options.version,
+                                          'unsupported WASI version');
+      }
+    } else {
+      // TODO(mdawson): Remove this in a SemVer major PR before Node.js 20
+      ({ WASI: _WASI } = internalBinding('wasi'));
+      this[kBindingName] = 'wasi_snapshot_preview1';
+    }
+
     if (options.args !== undefined)
       validateArray(options.args, 'options.args');
     const args = ArrayPrototypeMap(options.args || [], String);
@@ -138,8 +165,11 @@ class WASI {
       _initialize();
     }
   }
-}
 
+  getImportObject() {
+    return { [this[kBindingName]]: this.wasiImport };
+  }
+}
 
 module.exports = { WASI };
 

src/node_wasi.cc

@@ -1247,7 +1247,7 @@ void WASI::_SetMemory(const FunctionCallbackInfo<Value>& args) {
   wasi->memory_.Reset(wasi->env()->isolate(), args[0].As<WasmMemoryObject>());
 }
 
-static void Initialize(Local<Object> target,
+static void InitializePreview1(Local<Object> target,
                                Local<Value> unused,
                                Local<Context> context,
                                void* priv) {
@@ -1313,8 +1313,7 @@ static void Initialize(Local<Object> target,
   SetConstructorFunction(context, target, "WASI", tmpl);
 }
 
-
 }  // namespace wasi
 }  // namespace node
 
-NODE_BINDING_CONTEXT_AWARE_INTERNAL(wasi, node::wasi::Initialize)
+NODE_BINDING_CONTEXT_AWARE_INTERNAL(wasi, node::wasi::InitializePreview1)

test/wasi/test-wasi-options-validation.js

@@ -47,3 +47,12 @@ assert.throws(() => { new WASI({ stderr: 'fhqwhgads' }); },
 assert.throws(() => {
   new WASI({ preopens: { '/sandbox': '__/not/real/path' } });
 }, { code: 'UVWASI_ENOENT', message: /uvwasi_init/ });
+
+// If version is not a string, it should throw
+assert.throws(() => { new WASI({ version: { x: 'y' } }); },
+              { code: 'ERR_INVALID_ARG_TYPE', message: /\bversion\b/ });
+
+
+// If version is an unsupported version, it should throw
+assert.throws(() => { new WASI({ version: 'not_a_version' }); },
+              { code: 'ERR_INVALID_ARG_VALUE', message: /\bversion\b/ });

test/wasi/test-wasi.js

@@ -1,7 +1,8 @@
 'use strict';
 const common = require('../common');
 
-if (process.argv[2] === 'wasi-child') {
+if (process.argv[2] === 'wasi-child-default') {
+  // test default case
   const fixtures = require('../common/fixtures');
   const tmpdir = require('../common/tmpdir');
   const fs = require('fs');
@@ -30,12 +31,49 @@ if (process.argv[2] === 'wasi-child') {
 
     wasi.start(instance);
   })().then(common.mustCall());
+} else if (process.argv[2] === 'wasi-child-preview1') {
+  // Test version set to preview1
+  const assert = require('assert');
+  const fixtures = require('../common/fixtures');
+  const tmpdir = require('../common/tmpdir');
+  const fs = require('fs');
+  const path = require('path');
+
+  common.expectWarning('ExperimentalWarning',
+                       'WASI is an experimental feature and might change at any time');
+
+  const { WASI } = require('wasi');
+  tmpdir.refresh();
+  const wasmDir = path.join(__dirname, 'wasm');
+  const wasiPreview1 = new WASI({
+    version: 'preview1',
+    args: ['foo', '-bar', '--baz=value'],
+    env: process.env,
+    preopens: {
+      '/sandbox': fixtures.path('wasi'),
+      '/tmp': tmpdir.path,
+    },
+  });
+
+  // Validate the getImportObject helper
+  assert.strictEqual(wasiPreview1.wasiImport,
+                     wasiPreview1.getImportObject().wasi_snapshot_preview1);
+  const modulePathPreview1 = path.join(wasmDir, `${process.argv[3]}.wasm`);
+  const bufferPreview1 = fs.readFileSync(modulePathPreview1);
+
+  (async () => {
+    const { instance: instancePreview1 } =
+      await WebAssembly.instantiate(bufferPreview1,
+                                    wasiPreview1.getImportObject());
+
+    wasiPreview1.start(instancePreview1);
+  })().then(common.mustCall());
 } else {
   const assert = require('assert');
   const cp = require('child_process');
   const { checkoutEOL } = common;
 
-  function innerRunWASI(options, args) {
+  function innerRunWASI(options, args, flavor = 'default') {
     console.log('executing', options.test);
     const opts = {
       env: {
@@ -52,7 +90,7 @@ if (process.argv[2] === 'wasi-child') {
       ...args,
       '--experimental-wasi-unstable-preview1',
       __filename,
-      'wasi-child',
+      'wasi-child-' + flavor,
       options.test,
     ], opts);
     console.log(child.stderr.toString());
@@ -64,6 +102,7 @@ if (process.argv[2] === 'wasi-child') {
   function runWASI(options) {
     innerRunWASI(options, ['--no-turbo-fast-api-calls']);
     innerRunWASI(options, ['--turbo-fast-api-calls']);
+    innerRunWASI(options, ['--turbo-fast-api-calls'], 'preview1');
   }
 
   runWASI({ test: 'cant_dotdot' });