import.meta ponyfill

This library implements some standard interfaces of import.meta with the aim of resolving the confusion caused by multiple standards in Node.js. It includes unified support for the following Node.js standards:

How to use

• commonjs

  const import_meta_ponyfill = require("import-meta-ponyfill");
  const importMeta = import_meta_ponyfill(require, module);
  importMeta.resolve; // function
  importMeta.main; // boolean
  importMeta.url; // string
  importMeta.filename; // string
  importMeta.dirname; // string

• esmodule

  import import_meta_ponyfill from "import-meta-ponyfill";
  const importMeta = import_meta_ponyfill(import.meta);

  • v20.6.0, v18.19.0

    Unflag import.meta.resolve, with parentURL parameter still flagged.

  • v20.6.0, v18.19.0

    This API no longer throws when targeting file: URLs that do not map to an existing file on the local FS.

  • v20.0.0, v18.19.0

    This API now returns a string synchronously instead of a Promise.

  • v16.2.0, v14.18.0

    Add support for WHATWG URL object to parentURL parameter.

ImportMeta API

• url: string;

  A string representation of the fully qualified module URL. When the module is loaded locally, the value will be a file URL (e.g. file:///path/module.ts).

  You can also parse the string as a URL to determine more information about how the current module was loaded. For example to determine if a module was local or not:

  const url = new URL(importMeta.url);
  if (url.protocol === "file:") {
    console.log("this module was loaded locally");
  }

• resolve(specifier: string, parent?: string | URL | undefined): string;

  A function that returns the resolved specifier, see import.meta.resolve(specifier), even attempting to return a result for non-existent paths.

  console.log(importMeta.resolve("./foo.js"));
  // file:///dev/foo.js

  @param specifier The module specifier to resolve relative to parent. @param parent The absolute parent module URL to resolve from. @returns The absolute (file:) URL string for the resolved module.

• nodeResolve(specifier: string, parent?: string | URL | undefined): string;

  A function that returns resolved specifier as if it would be imported using import.meta.resolve(specifier) or require.resolve(specifier).

  console.log(import.meta.nodeResolve("./foo.js"));
  // file:///dev/foo.js

  @param specifier The module specifier to resolve relative to parent. @param parent The absolute parent module URL to resolve from. @returns The absolute (file:) URL string for the resolved module.

• main: boolean;

  A flag that indicates if the current module is the main module that was called when starting the program under Deno.

  if (importMeta.main) {
    // this was loaded as the main module, maybe do some bootstrapping
  }

• filename: string;

  The absolute path of the current module.

  This property is only provided for local modules (ie. using file:// URLs).

  Example:

  // Unix
  console.log(importMeta.filename); // /home/alice/my_module.ts
  
  // Windows
  console.log(importMeta.filename); // C:\alice\my_module.ts

• dirname: string;

  The absolute path of the directory containing the current module.

  This property is only provided for local modules (ie. using file:// URLs).

  Example:

  // Unix
  console.log(importMeta.dirname); // /home/alice
  
  // Windows
  console.log(importMeta.dirname); // C:\alice