feat: Add minimal polyfills for node.js modules

js/cli/.npmignore

@@ -1,3 +1,4 @@
 *
 !/target/**
+!/polyfills/**
 !/package.json

js/cli/package.json

@@ -8,12 +8,14 @@
   "main": "target/index.js",
   "types": "target/index.d.ts",
   "dependencies": {
+    "@jspm/core": "2.1.0",
     "archiver": "7.0.1",
     "axios": "1.7.7",
     "commander": "12.1.0",
     "decompress": "4.2.1",
     "esbuild": "0.24.0",
     "esbuild-plugin-tsc": "0.4.0",
+    "import-meta-resolve": "4.1.0",
     "readline-sync": "1.4.10"
   },
   "devDependencies": {

js/cli/polyfills/crypto.js

@@ -0,0 +1,87 @@
+import { Buffer } from "buffer"
+
+// limit of Crypto.getRandomValues()
+// https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues
+const MAX_BYTES = 65536;
+
+// Node supports requesting up to this number of bytes
+// https://github.com/nodejs/node/blob/master/lib/internal/crypto/random.js#L48
+const MAX_UINT32 = 4294967295;
+
+const JavaCrypto = Java.type("io.gatling.js.polyfills.Crypto");
+
+export const randomBytes = (size, cb) => {
+  // Node supports requesting up to this number of bytes
+  // https://github.com/nodejs/node/blob/master/lib/internal/crypto/random.js#L48
+  if (size > MAX_UINT32) {
+    throw new RangeError('requested too many random bytes');
+  }
+  const bytes = Buffer.from(JavaCrypto.randomBytes(size));
+  if (typeof cb === 'function') {
+    return process.nextTick(function () {
+      cb(null, bytes);
+    })
+  }
+  return bytes;
+};
+export const rng = randomBytes;
+export const pseudoRandomBytes = randomBytes;
+export const prng = randomBytes;
+export const getRandomValues = (values) => {
+  const byteView = new Uint8Array(values.buffer, values.byteOffset, values.byteLength);
+  const bytes = randomBytes(byteView.length);
+  for (let i = 0; i < byteView.length; i++) {
+    // The range of Math.random() is [0, 1) and the ToUint8 abstract operation rounds down
+    byteView[i] = bytes[i];
+  }
+  return values;
+};
+export const randomUUID = () => JavaCrypto.randomUUID();
+
+// export const Cipher = crypto.Cipher;
+// export const Cipheriv = crypto.Cipheriv;
+// export const Decipher = crypto.Decipher;
+// export const Decipheriv = crypto.Decipheriv;
+// export const DiffieHellman = crypto.DiffieHellman;
+// export const DiffieHellmanGroup = crypto.DiffieHellmanGroup;
+// export const Hash = crypto.Hash;
+// export const Hmac = crypto.Hmac;
+// export const Sign = crypto.Sign;
+// export const Verify = crypto.Verify;
+// export const constants = crypto.constants;
+// export const createCipher = crypto.createCipher;
+// export const createCipheriv = crypto.createCipheriv;
+// export const createCredentials = crypto.createCredentials;
+// export const createDecipher = crypto.createDecipher;
+// export const createDecipheriv = crypto.createDecipheriv;
+// export const createDiffieHellman = crypto.createDiffieHellman;
+// export const createDiffieHellmanGroup = crypto.createDiffieHellmanGroup;
+// export const createECDH = crypto.createECDH;
+// export const createHash = crypto.createHash;
+// export const createHmac = crypto.createHmac;
+// export const createSign = crypto.createSign;
+// export const createVerify = crypto.createVerify;
+// export const getCiphers = crypto.getCiphers;
+// export const getDiffieHellman = crypto.getDiffieHellman;
+// export const getHashes = crypto.getHashes;
+// export const listCiphers = crypto.listCiphers;
+// export const pbkdf2 = crypto.pbkdf2;
+// export const pbkdf2Sync = crypto.pbkdf2Sync;
+// export const privateDecrypt = crypto.privateDecrypt;
+// export const privateEncrypt = crypto.privateEncrypt;
+// export const publicDecrypt = crypto.publicDecrypt;
+// export const publicEncrypt = crypto.publicEncrypt;
+// export const randomFill = crypto.randomFill;
+// export const randomFillSync = crypto.randomFillSync;
+
+const crypto = {
+  randomBytes,
+  rng,
+  pseudoRandomBytes,
+  prng,
+  getRandomValues,
+  randomUUID,
+};
+crypto.webcrypto = crypto;
+globalThis.crypto = crypto;
+export default crypto;

js/cli/polyfills/global.js

@@ -0,0 +1,13 @@
+const global = globalThis;
+export { global };
+
+export { Buffer } from "buffer";
+
+// These values are used by some of the JSPM polyfills
+export const navigator = {
+  deviceMemory: 8, // Highest allowed value
+  hardwareConcurrency: 8, // Fairly common default
+  language: "en-US", // Most common default
+};
+
+export * as crypto from "crypto"

js/cli/src/bundle.ts → js/cli/src/bundle/index.ts

@@ -1,8 +1,9 @@
 import * as esbuild from "esbuild";
 import esbuildPluginTsc from "esbuild-plugin-tsc";
 
-import { SimulationFile } from "./simulations";
-import { logger } from "./log";
+import { polyfill } from "./polyfill";
+import { SimulationFile } from "../simulations";
+import { logger } from "../log";
 
 export interface BundleOptions {
   sourcesFolder: string;
@@ -20,12 +21,15 @@ export const bundle = async (options: BundleOptions): Promise<void> => {
   const contents = options.simulations.map((s) => `export { default as "${s.name}" } from "./${s.path}";`).join("\n");
 
   const plugins = options.typescript ? [esbuildPluginTsc({ force: true })] : [];
+  plugins.push(polyfill());
   await esbuild.build({
     stdin: {
       contents,
       resolveDir: options.sourcesFolder
     },
     outfile: options.bundleFile,
+    platform: "neutral",
+    mainFields: ["main", "module"],
     bundle: true,
     minify: false,
     sourcemap: true,

js/cli/src/bundle/polyfill.ts

@@ -0,0 +1,91 @@
+import type { Plugin } from "esbuild";
+import { fileURLToPath, pathToFileURL } from "url";
+import { resolve, dirname } from "path";
+
+// This is largely inspired by https://github.com/cyco130/esbuild-plugin-polyfill-node
+
+export const polyfill = (): Plugin => ({
+  name: "gatling-js-polyfill",
+  setup: async (build) => {
+    // modules
+    const jspmResolved = await resolveImport(`@jspm/core/nodelibs/fs`);
+    build.onResolve({ filter: polyfillsFilter }, async ({ path }) => {
+      const [, , moduleName] = path.match(polyfillsFilter)!;
+      const resolved = customPolyfills.find((name) => name === moduleName)
+        ? resolve(dirname(__filename), `../../polyfills/${moduleName}.js`)
+        : resolve(jspmResolved, `../../browser/${moduleName}.js`);
+      return { path: resolved };
+    });
+
+    // Globals
+    build.initialOptions.inject = build.initialOptions.inject || [];
+    const injectGlobal = (name: string) =>
+      (build.initialOptions.inject as string[]).push(resolve(dirname(__filename), `../../polyfills/${name}.js`));
+    injectGlobal("global");
+  }
+});
+
+const customPolyfills = ["crypto"];
+
+const jspmPolyfills = ["buffer", "path", "string_decoder"];
+
+// Other available jspm-core modules:
+// "_stream_duplex"
+// "_stream_passthrough"
+// "_stream_readable"
+// "_stream_transform"
+// "_stream_writable"
+// "assert"
+// "assert/strict"
+// "async_hooks"
+// "child_process"
+// "cluster"
+// "console"
+// "constants"
+// "crypto"
+// "dgram"
+// "diagnostics_channel"
+// "dns"
+// "domain"
+// "events"
+// "fs"
+// "fs/promises"
+// "http"
+// "http2"
+// "https"
+// "module"
+// "net"
+// "os"
+// "perf_hooks"
+// "process"
+// "punycode"
+// "querystring"
+// "readline"
+// "repl"
+// "stream"
+// "sys"
+// "timers"
+// "timers/promises"
+// "tls"
+// "tty"
+// "url"
+// "util"
+// "v8"
+// "vm"
+// "wasi"
+// "worker_threads"
+// "zlib"
+
+const polyfillsFilter = new RegExp(`^(node:)?(${jspmPolyfills.concat(customPolyfills).join("|")})$`);
+
+let importMetaResolve: (specifier: string, parent: string) => string;
+
+const importMetaUrl = pathToFileURL(__filename).href;
+
+const resolveImport = async (specifier: string) => {
+  if (!importMetaResolve) {
+    importMetaResolve = (await import("import-meta-resolve")).resolve;
+  }
+  const resolved = importMetaResolve(specifier, importMetaUrl);
+  return fileURLToPath(resolved);
+};