feat: export Ignore symbol

Author: JounQin

index.js

@@ -13,5 +13,6 @@
 
 // it’s mostly private, but useful for tools like `eslint-mdx`.
 export {Configuration} from './lib/configuration.js'
+export {Ignore} from './lib/ignore.js'
 
 export {engine} from './lib/index.js'

readme.md

@@ -19,6 +19,7 @@
 * [API](#api)
   * [`engine(options, callback)`](#engineoptions-callback)
   * [`Configuration`](#configuration)
+  * [`Ignore`](#ignore)
   * [`Completer`](#completer)
   * [`Callback`](#callback)
   * [`ConfigResult`](#configresult)
@@ -150,7 +151,7 @@ function done(error, code) {
 
 ## API
 
-This package exports the identifiers [`Configuration`][api-configuration] and
+This package exports the identifiers [`Configuration`][api-configuration], [`Ignore`][api-ignore] and
 [`engine`][api-engine].
 There is no default export.
 
@@ -175,6 +176,13 @@ Internal class to load configuration files.
 
 Exposed to build more complex integrations.
 
+### `Ignore`
+
+Internal class to load ignore file for checking
+whether this file should be ignored.
+
+Exposed to build more complex integrations.
+
 ###### Parameters
 
 * `options` (subset of [`Options`][api-options], required)
@@ -1595,6 +1603,8 @@ abide by its terms.
 
 [api-file-set]: #fileset
 
+[api-ignore]: #ignore
+
 [api-options]: #options
 
 [api-preset]: #preset

test/core.js

@@ -10,6 +10,7 @@ test('engine', async function (t) {
   await t.test('should expose the public api', async function () {
     assert.deepEqual(Object.keys(await import('unified-engine')).sort(), [
       'Configuration',
+      'Ignore',
       'engine'
     ])
   })