Inject Node.js built-in into the JavaScript sandbox for adapters

integrations/python-adapter/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "capsule-run-adapter"
-version = "0.3.4"
+version = "0.3.5"
 description = "Capsule adapter for Python applications — execute Python and JavaScript code in isolated WebAssembly sandboxes"
 license = { text = "Apache-2.0" }
 readme = "README.md"

integrations/python-adapter/src/js_sandbox/execution.ts

@@ -1,3 +1,7 @@
+import { fs, path, os, process } from "@capsule-run/sdk";
+
+const fsPromises = fs.promises;
+
 function hoistDeclarations(code: string): string {
   let depth = 0;
   let i = 0;
@@ -126,8 +130,41 @@ function hoistDeclarations(code: string): string {
   return out;
 }
 
+/**
+ * Maps module names user code can import to their sandbox equivalents.
+ * These are the WASI polyfills from the capsule SDK.
+ */
+export const MODULE_REGISTRY: Record<string, unknown> = {
+  "fs":               fs,
+  "fs/promises":      fsPromises,
+  "node:fs":          fs,
+  "node:fs/promises": fsPromises,
+  "path":             path,
+  "node:path":        path,
+  "os":               os,
+  "node:os":          os,
+  "process":          process,
+  "node:process":     process,
+};
+
+export const MODULE_VALUES: Set<unknown> = new Set(Object.values(MODULE_REGISTRY));
+export const TRANSIENT_KEYS: Set<string> = new Set(["__require__", "require"]);
+
+
+function rewriteImports(code: string): string {
+  return code.replace(
+    /^[ \t]*import\s+(?:(\*\s+as\s+\w+|\{[^}]*\}|\w+)\s+from\s+)?['"]([^'"]+)['"]\s*;?/gm,
+    (_, binding: string | undefined, mod: string) => {
+      if (!binding) return `__require__('${mod}');`;
+      const normalized = binding.replace(/^\*\s+as\s+/, "");
+      return `var ${normalized} = __require__('${mod}');`;
+    }
+  );
+}
+
 export function _executeCode(code: string, env: Record<string, unknown>): unknown {
-  code = hoistDeclarations(code);
+  code = rewriteImports(hoistDeclarations(code));
+
   const capturedOutput: string[] = [];
   const originalLog = console.log;
 
@@ -136,6 +173,12 @@ export function _executeCode(code: string, env: Record<string, unknown>): unknow
   };
 
   try {
+    env.__require__ = (mod: string): unknown => {
+      if (mod in MODULE_REGISTRY) return MODULE_REGISTRY[mod];
+      throw new Error(`Cannot import '${mod}': module is not available in the sandbox`);
+    };
+    env.require = env.__require__;
+
     const proxy = new Proxy(env, {
       has(_t, _k) { return true; },
       get(t, k) {

integrations/python-adapter/src/js_sandbox/serialization.ts

@@ -1,3 +1,5 @@
+import { MODULE_VALUES, TRANSIENT_KEYS, MODULE_REGISTRY } from "./execution";
+
 export type SerializedValue =
   | { __type__: "primitive"; value: string | number | boolean | null }
   | { __type__: "undefined" }
@@ -13,6 +15,7 @@ export type SerializedValue =
   | { __type__: "classdef"; __source__: string }
   | { __type__: "function"; __source__: string }
   | { __type__: "instance"; __class__: string; __source__: string; __dict__: Record<string, SerializedValue> }
+  | { __type__: "module"; name: string }  // use for import/require() modules
   | null;
 
 export function serializeValue(val: unknown): SerializedValue {
@@ -96,16 +99,29 @@ export function serializeValue(val: unknown): SerializedValue {
   return null;
 }
 
+const MODULE_VALUE_TO_NAME: Map<unknown, string> = new Map(
+  Object.entries(MODULE_REGISTRY)
+    .filter(([name]) => !name.startsWith("node:"))
+    .map(([name, val]) => [val, name])
+);
+
 export function serializeEnv(env: Record<string, unknown>): Record<string, SerializedValue> {
   const out: Record<string, SerializedValue> = {};
   for (const [key, val] of Object.entries(env)) {
     if (key.startsWith("__")) continue;
+    if (TRANSIENT_KEYS.has(key)) continue;
+    if (MODULE_VALUES.has(val)) {
+      const name = MODULE_VALUE_TO_NAME.get(val);
+      if (name) out[key] = { __type__: "module", name };
+      continue;
+    }
     const s = serializeValue(val);
     if (s !== null) out[key] = s;
   }
   return out;
 }
 
+
 export function deserializeValue(
   entry: SerializedValue,
   classes: Record<string, new (...args: unknown[]) => unknown>
@@ -153,6 +169,8 @@ export function deserializeValue(
       }
       return instance;
     }
+    case "module":
+      return MODULE_REGISTRY[entry.name];
     default:
       return undefined;
   }

integrations/typescript-adapter/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@capsule-run/adapter",
-  "version": "0.3.4",
+  "version": "0.3.5",
   "description": "Capsule adapter for typescript applications",
   "license": "Apache-2.0",
   "author": "",

integrations/typescript-adapter/src/js_sandbox/execution.ts

@@ -1,3 +1,7 @@
+import { fs, path, os, process } from "@capsule-run/sdk";
+
+const fsPromises = fs.promises;
+
 function hoistDeclarations(code: string): string {
   let depth = 0;
   let i = 0;
@@ -126,8 +130,41 @@ function hoistDeclarations(code: string): string {
   return out;
 }
 
+/**
+ * Maps module names user code can import to their sandbox equivalents.
+ * These are the WASI polyfills from the capsule SDK.
+ */
+export const MODULE_REGISTRY: Record<string, unknown> = {
+  "fs":               fs,
+  "fs/promises":      fsPromises,
+  "node:fs":          fs,
+  "node:fs/promises": fsPromises,
+  "path":             path,
+  "node:path":        path,
+  "os":               os,
+  "node:os":          os,
+  "process":          process,
+  "node:process":     process,
+};
+
+export const MODULE_VALUES: Set<unknown> = new Set(Object.values(MODULE_REGISTRY));
+export const TRANSIENT_KEYS: Set<string> = new Set(["__require__", "require"]);
+
+
+function rewriteImports(code: string): string {
+  return code.replace(
+    /^[ \t]*import\s+(?:(\*\s+as\s+\w+|\{[^}]*\}|\w+)\s+from\s+)?['"]([^'"]+)['"]\s*;?/gm,
+    (_, binding: string | undefined, mod: string) => {
+      if (!binding) return `__require__('${mod}');`;
+      const normalized = binding.replace(/^\*\s+as\s+/, "");
+      return `var ${normalized} = __require__('${mod}');`;
+    }
+  );
+}
+
 export function _executeCode(code: string, env: Record<string, unknown>): unknown {
-  code = hoistDeclarations(code);
+  code = rewriteImports(hoistDeclarations(code));
+
   const capturedOutput: string[] = [];
   const originalLog = console.log;
 
@@ -136,6 +173,12 @@ export function _executeCode(code: string, env: Record<string, unknown>): unknow
   };
 
   try {
+    env.__require__ = (mod: string): unknown => {
+      if (mod in MODULE_REGISTRY) return MODULE_REGISTRY[mod];
+      throw new Error(`Cannot import '${mod}': module is not available in the sandbox`);
+    };
+    env.require = env.__require__;
+
     const proxy = new Proxy(env, {
       has(_t, _k) { return true; },
       get(t, k) {

integrations/typescript-adapter/src/js_sandbox/serialization.ts

@@ -1,3 +1,5 @@
+import { MODULE_VALUES, TRANSIENT_KEYS, MODULE_REGISTRY } from "./execution";
+
 export type SerializedValue =
   | { __type__: "primitive"; value: string | number | boolean | null }
   | { __type__: "undefined" }
@@ -13,6 +15,7 @@ export type SerializedValue =
   | { __type__: "classdef"; __source__: string }
   | { __type__: "function"; __source__: string }
   | { __type__: "instance"; __class__: string; __source__: string; __dict__: Record<string, SerializedValue> }
+  | { __type__: "module"; name: string }  // use for import/require() modules
   | null;
 
 export function serializeValue(val: unknown): SerializedValue {
@@ -96,16 +99,29 @@ export function serializeValue(val: unknown): SerializedValue {
   return null;
 }
 
+const MODULE_VALUE_TO_NAME: Map<unknown, string> = new Map(
+  Object.entries(MODULE_REGISTRY)
+    .filter(([name]) => !name.startsWith("node:"))
+    .map(([name, val]) => [val, name])
+);
+
 export function serializeEnv(env: Record<string, unknown>): Record<string, SerializedValue> {
   const out: Record<string, SerializedValue> = {};
   for (const [key, val] of Object.entries(env)) {
     if (key.startsWith("__")) continue;
+    if (TRANSIENT_KEYS.has(key)) continue;
+    if (MODULE_VALUES.has(val)) {
+      const name = MODULE_VALUE_TO_NAME.get(val);
+      if (name) out[key] = { __type__: "module", name };
+      continue;
+    }
     const s = serializeValue(val);
     if (s !== null) out[key] = s;
   }
   return out;
 }
 
+
 export function deserializeValue(
   entry: SerializedValue,
   classes: Record<string, new (...args: unknown[]) => unknown>
@@ -153,6 +169,8 @@ export function deserializeValue(
       }
       return instance;
     }
+    case "module":
+      return MODULE_REGISTRY[entry.name];
     default:
       return undefined;
   }