Load module from string using
requireorimport.
npm GitHub Workflow Status (branch) Node.js libera manifesto
npm install module-from-string
import { requireFromString, importFromString, importFromStringSync } from 'module-from-string' requireFromString("module.exports = 'hi'") // => 'hi' requireFromString("exports.greet = 'hi'") // => { greet: 'hi' } ;(async () => { await importFromString("export default 'hi'") // => { default: 'hi' } })() importFromStringSync( "export const greet = Buffer.from([0x68, 0x69]).toString('utf8')", { globals: { Buffer } } ) // => { greet: 'hi' }
import { Context } from 'vm'; import { TransformOptions } from 'esbuild'; interface Options { filename?: string dirname?: string globals?: Context useCurrentGlobal?: boolean } declare const requireFromString: (code: string, options?: Options) => any declare const createRequireFromString: (options?: Options) => typeof requireFromString interface ImportOptions extends Options { transformOptions?: TransformOptions } declare const importFromString: (code: string, options?: ImportOptions) => Promise<any> declare const createImportFromString: (options?: ImportOptions) => typeof importFromString declare const importFromStringSync: (code: string, options?: ImportOptions) => any declare const createImportFromStringSync: (options?: ImportOptions) => typeof importFromStringSync
Name, path or URL string of the virtual file for better exception stack trace.
requireFromString( "throw new Error('boom!')", { filename: '/home/foo.js' } ) // /home/foo.js:1 // throw new Error('boom!') // ^ // // Error: boom! // at /home/foo.js:1:7 // at ...
Path or URL string of the directory for resolving require or import from relative path.
requireFromString( "module.exports = require('.')", { dirname: path.join(__dirname, "../lib") } ) // => require('../lib')
If not specified, the default value will be the current file's directory.
Underneath the hood, module-from-string uses Node.js built-in vm module to execute code.
// requireFromString vm.runInNewContext( code, { __dirname: contextModule.path, __filename: contextModule.filename, exports: contextModule.exports, module: contextModule, require: contextModule.require, ...globals },
Take requireFromString for example, only the module scope variables are passed into the contextObject.
In order to use other global objects that are specific to Node.js, they need to be added to option globals or set option useCurrentGlobal to true.
requireFromString( 'module.exports = process.cwd()', { globals: { process } } ) // => $PWD
Note: by default the built-in objects have a different prototype.
const error = requireFromString('module.exports = new Error()') error instanceof Error // => false
Default to false. If set to true, all the available variables from the current global (or globalThis) are passed into the context.
Function importFromString and importFromStringSync can use esbuild to transform code syntax. See esbuild Transform API for documentation.
const { greet } = importFromStringSync( "export const greet: () => string = () => 'hi'", { transformOptions: { loader: 'ts' } } ) greet() // => 'hi'
Dynamic import() expression of ES modules is supported by all three functions requireFromString, importFromString and importFromStringSync.
;(async () => { await requireFromString("module.exports = import('./index.mjs')") })()
import statement of ES modules is supported only by asynchronous function importFromString using Node.js experimental API vm.Module.
node --experimental-vm-modules index.js
# Or use environment variable
NODE_OPTIONS=--experimental-vm-modules node index.js// with top-level await await importFromString("export { foo as default } from './index.mjs'")
MIT License © 2021 Exuanbo