node_globals_inject plugin

This plugin supports commonjs -> esm syntax for commonjs node constants like __filename and __dirname.

In effect, this plugin will add the following declarations to any file where we find __filename or __dirname.

``typescript
import { fileURLToPath } from "url"
import { dirname } from "path"

const __dirname = dirname(fileURLToPath(import.meta.url))
const __filename = fileURLToPath(import.meta.url)
`

Usage

$3

`json
plugins: [
[
"@swc/plugin-relay",
{
// Optional - This will change how we do function imports (only change this is you need to avoid name collisions from the default - see below)
"funcAliasPrefix": "__from_plugin_",
},
],
],
`

Design Details

This plugin will:

1. Scan each file to determine if __dirname or __filename are used in the file
2. For files with those usages, it will inject the necessary library imports and const declations:

$3


1. If both dirname and fileURLToPath are imported, it will inject the declarations right after the last import
`typescript
import something from 'something';
import { fileURLToPath } from 'url';
import else from 'else';
import { dirname } from 'path';
// Injected here
const __dirname = dirname(fileURLToPath(import.meta.url))
const __filename = fileURLToPath(import.meta.url)
`
2. If only 1 function is imported, it will inject an aliased import of the other function and then the declarations after that import
`typescript
import something from 'something';
import { fileURLToPath } from 'url';
// injected here
import { dirname as __swc_shim_dirname } from 'path';
const __dirname = __swc_shim_dirname(fileURLToPath(import.meta.url))
const __filename = fileURLToPath(import.meta.url)
import else from 'else';
`
3. If star imports (* as foo from 'path') are used, it will use the star object notation and just inject the declarations
`typescript
import something from 'something';
import * as url from 'url';
import else from 'else';
import { dirname } from 'path';
// Injected here
const __dirname = dirname(url.fileURLToPath(import.meta.url))
const __filename = url.fileURLToPath(import.meta.url)
`
4. If no imports already exists, it will inject aliased imports and then the declarations
`typescript
// Injected here
import { dirname as __swc_shim_dirname } from 'path';
import { fileURLToPath as __swc_shim_fileURLToPath } from 'path';
const __dirname = __swc_shim_dirname(__swc_shim_fileURLToPath(import.meta.url))
const __filename = __swc_shim_fileURLToPath(import.meta.url)
import something from 'something';
import else from 'else';
``