feat(NODE-6321): remove require('crypto') from Nodejs bundle (#825)

Author: baileympearson

etc/rollup/rollup-plugin-require-rewriter/require_rewriter.mjs

@@ -115,4 +115,4 @@
     "prepare": "node etc/prepare.js",
     "release": "standard-version -i HISTORY.md"
   }
-}
+}

package.json

@@ -1,6 +1,5 @@
 import { nodeResolve } from '@rollup/plugin-node-resolve';
 import typescript from '@rollup/plugin-typescript';
-import { requireRewriter } from './etc/rollup/rollup-plugin-require-rewriter/require_rewriter.mjs';
 import { RequireVendor } from './etc/rollup/rollup-plugin-require-vendor/require_vendor.mjs';
 
 /** @type {typescript.RollupTypescriptOptions} */
@@ -57,7 +56,6 @@ const config = [
     input,
     plugins: [
       typescript(tsConfig),
-      requireRewriter({ target: 'browser' }),
       nodeResolve({ resolveOnly: [] })
     ],
     output: {
@@ -68,7 +66,7 @@ const config = [
   },
   {
     input,
-    plugins: [typescript(tsConfig), requireRewriter({ target: 'node' }), nodeResolve({ resolveOnly: [] })],
+    plugins: [typescript(tsConfig), nodeResolve({ resolveOnly: [] })],
     output: {
       file: 'lib/bson.node.mjs',
       format: 'esm',

rollup.config.mjs

@@ -26,34 +26,27 @@ type NodeJsBufferConstructor = Omit<Uint8ArrayConstructor, 'from'> & {
 // This can be nullish, but we gate the nodejs functions on being exported whether or not this exists
 // Node.js global
 declare const Buffer: NodeJsBufferConstructor;
-declare const require: (mod: 'crypto') => { randomBytes: (byteLength: number) => Uint8Array };
 
 /** @internal */
-export function nodejsMathRandomBytes(byteLength: number) {
+function nodejsMathRandomBytes(byteLength: number): NodeJsBuffer {
   return nodeJsByteUtils.fromNumberArray(
     Array.from({ length: byteLength }, () => Math.floor(Math.random() * 256))
   );
 }
 
-/**
- * @internal
- * WARNING: REQUIRE WILL BE REWRITTEN
- *
- * This code is carefully used by require_rewriter.mjs any modifications must be reflected in the plugin.
- *
- * @remarks
- * "crypto" is the only dependency BSON needs. This presents a problem for creating a bundle of the BSON library
- * in an es module format that can be used both on the browser and in Node.js. In Node.js when BSON is imported as
- * an es module, there will be no global require function defined, making the code below fallback to the much less desireable math.random bytes.
- * In order to make our es module bundle work as expected on Node.js we need to change this `require()` to a dynamic import, and the dynamic
- * import must be top-level awaited since es modules are async. So we rely on a custom rollup plugin to seek out the following lines of code
- * and replace `require` with `await import` and the IIFE line (`nodejsRandomBytes = (() => { ... })()`) with `nodejsRandomBytes = await (async () => { ... })()`
- * when generating an es module bundle.
- */
-const nodejsRandomBytes: (byteLength: number) => Uint8Array = (() => {
-  try {
-    return require('crypto').randomBytes;
-  } catch {
+/** @internal */
+function nodejsSecureRandomBytes(byteLength: number): NodeJsBuffer {
+  // @ts-expect-error: crypto.getRandomValues cannot actually be null here
+  return crypto.getRandomValues(nodeJsByteUtils.allocate(byteLength));
+}
+
+const nodejsRandomBytes = (() => {
+  const { crypto } = globalThis as {
+    crypto?: { getRandomValues?: (space: Uint8Array) => Uint8Array };
+  };
+  if (crypto != null && typeof crypto.getRandomValues === 'function') {
+    return nodejsSecureRandomBytes;
+  } else {
     return nodejsMathRandomBytes;
   }
 })();