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remix/assets/types/hmr · Interface

ImportMeta

Summary

The type of import.meta.

If you need to declare that a given property exists on import.meta, this type may be augmented via interface merging.

Signature

interface ImportMeta {
  dirname: string
  filename: string
  hot?: ImportMetaHot
  main: boolean
  url: string
  resolve(specifier: string): string
  resolve(specifier: string, parent: string | URL): string
}

Properties

dirname

The directory name of the current module.

This is the same as the path.dirname() of the import.meta.filename.

Caveat: only present on file: modules.

filename

The full absolute path and filename of the current module, with symlinks resolved.

This is the same as the url.fileURLToPath() of the import.meta.url.

Caveat only local modules support this property. Modules not using the file: protocol will not provide it.

hot

main

true when the current module is the entry point of the current process; false otherwise.

Equivalent to require.main === module in CommonJS.

Analogous to Python's __name__ == "__main__".

export function foo() {
  return 'Hello, world';
}

function main() {
  const message = foo();
  console.log(message);
}

if (import.meta.main) main();
// `foo` can be imported from another module without possible side-effects from `main`

url

The absolute file: URL of the module.

This is defined exactly the same as it is in browsers providing the URL of the current module file.

This enables useful patterns such as relative file loading:

import { readFileSync } from 'node:fs';
const buffer = readFileSync(new URL('./data.proto', import.meta.url));

Methods

resolve(specifier: string): string

resolve(specifier: string, parent: string | URL): string

import.meta.resolve is a module-relative resolution function scoped to each module, returning the URL string.

const dependencyAsset = import.meta.resolve('component-lib/asset.css');
// file:///app/node_modules/component-lib/asset.css
import.meta.resolve('./dep.js');
// file:///app/dep.js

All features of the Node.js module resolution are supported. Dependency resolutions are subject to the permitted exports resolutions within the package.

Caveats:

  • This can result in synchronous file-system operations, which can impact performance similarly to require.resolve.
  • This feature is not available within custom loaders (it would create a deadlock).

Parameters

specifier

The module specifier to resolve relative to the current module.

parent

An optional absolute parent module URL to resolve from. Default: import.meta.url