languageOptions

See the source

Configures the ECMAScript version and module source type for your project.

Defaults

Option	Default
ecmaVersion	"latest"
sourceType	"module"

Options

uglify({
  with: ["languageOptions"],
  options: {
    languageOptions: {
      ecmaVersion: 2022,
      sourceType: "module",
      additionalGlobals: {
        myGlobal: "readonly",
      },
    },
  },
})

ecmaVersion

The ECMAScript version to parse. Default: "latest".

sourceType

Either "module" (ESM) or "commonjs". Default: "module".

additionalGlobals

An object of additional global variables to define. Keys are variable names, values are "readonly" or "writable".

Note

You typically don’t need this block explicitly — the environment configs (node, web, etc.) set language options automatically. Use this when you need fine-grained control over the ECMAScript version or source type.