cmux/node_modules/@edge-runtime/vm/dist/edge-vm.js
2026-01-29 17:36:26 -08:00

338 lines
No EOL
12 KiB
JavaScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.EdgeVM = void 0;
const load_1 = require("@edge-runtime/primitives/load");
const vm_1 = require("vm");
const vm_2 = require("./vm");
/**
* Store handlers that the user defined from code so that we can invoke them
* from the Node.js realm.
*/
let unhandledRejectionHandlers;
let uncaughtExceptionHandlers;
class EdgeVM extends vm_2.VM {
constructor(options) {
super({
...options,
extend: (context) => {
return (options === null || options === void 0 ? void 0 : options.extend)
? options.extend(addPrimitives(context))
: addPrimitives(context);
},
});
Object.defineProperty(this.context, '__onUnhandledRejectionHandlers', {
set: registerUnhandledRejectionHandlers,
configurable: false,
enumerable: false,
});
Object.defineProperty(this, '__rejectionHandlers', {
get: () => unhandledRejectionHandlers,
configurable: false,
enumerable: false,
});
Object.defineProperty(this.context, '__onErrorHandlers', {
set: registerUncaughtExceptionHandlers,
configurable: false,
enumerable: false,
});
Object.defineProperty(this, '__errorHandlers', {
get: () => uncaughtExceptionHandlers,
configurable: false,
enumerable: false,
});
this.evaluate(getDefineEventListenersCode());
this.dispatchFetch = this.evaluate(getDispatchFetchCode());
for (const name of transferableConstructors) {
patchInstanceOf(name, this.context);
}
if (options === null || options === void 0 ? void 0 : options.initialCode) {
this.evaluate(options.initialCode);
}
}
}
exports.EdgeVM = EdgeVM;
/**
* Transferable constructors are the constructors that we expect to be
* "shared" between the realms.
*
* When a user creates an instance of one of these constructors, we want
* to make sure that the `instanceof` operator works as expected:
*
* * If the instance was created in the Node.js realm, then `instanceof`
* should return true when used in the EdgeVM realm.
* * If the instance was created in the EdgeVM realm, then `instanceof`
* should return true when used in the EdgeVM realm.
*
* For example, the return value from `new TextEncoder().encode("hello")` is a
* Uint8Array. Since `TextEncoder` implementation is coming from the Node.js realm,
* therefore the following will be false, which doesn't fit the expectation of the user:
* ```ts
* new TextEncoder().encode("hello") instanceof Uint8Array
* ```
*
* This is because the `Uint8Array` in the `vm` context is not the same
* as the one in the Node.js realm.
*
* Patching the constructors in the `vm` is done by the {@link patchInstanceOf}
* function, and this is the list of constructors that need to be patched.
*
* These constructors are also being injected as "globals" when the VM is
* constructed, by passing them as arguments to the {@link loadPrimitives}
* function.
*/
const transferableConstructors = [
'Object',
'Array',
'RegExp',
'Uint8Array',
'ArrayBuffer',
'Error',
'SyntaxError',
'TypeError',
];
function patchInstanceOf(item, ctx) {
// @ts-ignore
ctx[Symbol.for(`node:${item}`)] = eval(item);
return (0, vm_1.runInContext)(`
globalThis.${item} = new Proxy(${item}, {
get(target, prop, receiver) {
if (prop === Symbol.hasInstance && receiver === globalThis.${item}) {
const nodeTarget = globalThis[Symbol.for('node:${item}')];
if (nodeTarget) {
return function(instance) {
return instance instanceof target || instance instanceof nodeTarget;
};
} else {
throw new Error('node target must exist')
}
}
return Reflect.get(target, prop, receiver);
}
})
`, ctx);
}
/**
* Register system-level handlers to make sure that we report to the user
* whenever there is an unhandled rejection or exception before the process crashes.
* Do it on demand so we don't swallow rejections/errors for no reason.
*/
function registerUnhandledRejectionHandlers(handlers) {
if (!unhandledRejectionHandlers) {
process.on('unhandledRejection', function invokeRejectionHandlers(reason, promise) {
unhandledRejectionHandlers.forEach((handler) => handler({ reason, promise }));
});
}
unhandledRejectionHandlers = handlers;
}
function registerUncaughtExceptionHandlers(handlers) {
if (!uncaughtExceptionHandlers) {
process.on('uncaughtException', function invokeErrorHandlers(error) {
uncaughtExceptionHandlers.forEach((handler) => handler(error));
});
}
uncaughtExceptionHandlers = handlers;
}
/**
* Generates polyfills for addEventListener and removeEventListener. It keeps
* all listeners in hidden property __listeners. It will also call a hook
* `__onUnhandledRejectionHandler` and `__onErrorHandler` when unhandled rejection
* events are added or removed and prevent from having more than one FetchEvent
* handler.
*/
function getDefineEventListenersCode() {
return `
Object.defineProperty(self, '__listeners', {
configurable: false,
enumerable: false,
value: {},
writable: true,
})
function __conditionallyUpdatesHandlerList(eventType) {
if (eventType === 'unhandledrejection') {
self.__onUnhandledRejectionHandlers = self.__listeners[eventType];
} else if (eventType === 'error') {
self.__onErrorHandlers = self.__listeners[eventType];
}
}
function addEventListener(type, handler) {
const eventType = type.toLowerCase();
if (eventType === 'fetch' && self.__listeners.fetch) {
throw new TypeError('You can register just one "fetch" event listener');
}
self.__listeners[eventType] = self.__listeners[eventType] || [];
self.__listeners[eventType].push(handler);
__conditionallyUpdatesHandlerList(eventType);
}
function removeEventListener(type, handler) {
const eventType = type.toLowerCase();
if (self.__listeners[eventType]) {
self.__listeners[eventType] = self.__listeners[eventType].filter(item => {
return item !== handler;
});
if (self.__listeners[eventType].length === 0) {
delete self.__listeners[eventType];
}
}
__conditionallyUpdatesHandlerList(eventType);
}
`;
}
/**
* Generates the code to dispatch a FetchEvent invoking the handlers defined
* for such events. In case there is no event handler defined it will throw
* an error.
*/
function getDispatchFetchCode() {
return `(async function dispatchFetch(input, init) {
const request = new Request(input, init);
const event = new FetchEvent(request);
if (!self.__listeners.fetch) {
throw new Error("No fetch event listeners found");
}
const getResponse = ({ response, error }) => {
if (error || !response || !(response instanceof Response)) {
console.error(error ? error.toString() : 'The event listener did not respond')
response = new Response(null, {
statusText: 'Internal Server Error',
status: 500
})
}
response.waitUntil = () => Promise.all(event.awaiting);
if (response.status < 300 || response.status >= 400 ) {
response.headers.delete('content-encoding');
response.headers.delete('transform-encoding');
response.headers.delete('content-length');
}
return response;
}
try {
await self.__listeners.fetch[0].call(event, event)
} catch (error) {
return getResponse({ error })
}
return Promise.resolve(event.response)
.then(response => getResponse({ response }))
.catch(error => getResponse({ error }))
})`;
}
function addPrimitives(context) {
defineProperty(context, 'self', { enumerable: true, value: context });
defineProperty(context, 'globalThis', { value: context });
defineProperty(context, 'Symbol', { value: Symbol });
defineProperty(context, 'clearInterval', { value: clearInterval });
defineProperty(context, 'clearTimeout', { value: clearTimeout });
defineProperty(context, 'queueMicrotask', { value: queueMicrotask });
defineProperty(context, 'EdgeRuntime', { value: 'edge-runtime' });
const transferables = getTransferablePrimitivesFromContext(context);
defineProperties(context, {
exports: (0, load_1.load)({
...transferables,
WeakRef: (0, vm_1.runInContext)(`WeakRef`, context),
}),
enumerable: ['crypto'],
nonenumerable: [
// Crypto
'Crypto',
'CryptoKey',
'SubtleCrypto',
// Fetch APIs
'fetch',
'File',
'FormData',
'Headers',
'Request',
'Response',
'WebSocket',
// Structured Clone
'structuredClone',
// Blob
'Blob',
// URL
'URL',
'URLSearchParams',
'URLPattern',
// AbortController
'AbortController',
'AbortSignal',
'DOMException',
// Streams
'ReadableStream',
'ReadableStreamBYOBReader',
'ReadableStreamDefaultReader',
'TextDecoderStream',
'TextEncoderStream',
'TransformStream',
'WritableStream',
'WritableStreamDefaultWriter',
// Encoding
'atob',
'btoa',
'TextEncoder',
'TextDecoder',
// Events
'Event',
'EventTarget',
'FetchEvent',
'PromiseRejectionEvent',
// Console
'console',
// Performance
'performance',
// Timers
'setTimeout',
'setInterval',
],
});
return context;
}
function defineProperty(obj, prop, attrs) {
var _a, _b, _c;
Object.defineProperty(obj, prop, {
configurable: (_a = attrs.configurable) !== null && _a !== void 0 ? _a : false,
enumerable: (_b = attrs.enumerable) !== null && _b !== void 0 ? _b : false,
value: attrs.value,
writable: (_c = attrs.writable) !== null && _c !== void 0 ? _c : true,
});
}
function defineProperties(context, options) {
var _a, _b;
for (const property of (_a = options.enumerable) !== null && _a !== void 0 ? _a : []) {
if (!options.exports[property]) {
throw new Error(`Attempt to export a nullable value for "${property}"`);
}
defineProperty(context, property, {
enumerable: true,
value: options.exports[property],
});
}
for (const property of (_b = options.nonenumerable) !== null && _b !== void 0 ? _b : []) {
if (!options.exports[property]) {
throw new Error(`Attempt to export a nullable value for "${property}"`);
}
defineProperty(context, property, {
value: options.exports[property],
});
}
}
/**
* Create an object that contains all the {@link transferableConstructors}
* implemented in the provided context.
*/
function getTransferablePrimitivesFromContext(context) {
const keys = transferableConstructors.join(',');
const stringifedObject = `({${keys}})`;
return (0, vm_1.runInContext)(stringifedObject, context);
}
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