exuanbomodule-from-string
Load module from string using
requireorimport.
Install
npm install module-from-stringUsage
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' }API
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 importFromStringSyncfilename
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 ...dirname
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.
globals
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 } }
) // => $PWDNote: by default the built-in objects have a different prototype.
const error = requireFromString('module.exports = new Error()')
error instanceof Error // => falseuseCurrentGlobal
Default to false. If set to true, all the available variables from the current global (or globalThis) are passed into the context.
transformOptions
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'ES modules
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'")License
MIT License © 2021 Exuanbo