Add sync transform if w/ only explicit plugins

lib/index.js

@@ -44,6 +44,27 @@ export default function remarkTextr(options) {
   const settings = options || emptyOptions
   const plugins = settings.plugins || []
   const textrOptions = settings.options || {}
+
+  const needsPromise = plugins.some((plugin) => typeof plugin === 'string')
+
+  if (!needsPromise) {
+    const typography = textr(textrOptions).use(...plugins)
+
+    /**
+     * Transform synchronously.
+     *
+     * @param {Root} tree
+     *   Tree.
+     * @returns {undefined}
+     *   Nothing.
+     */
+    return function (tree) {
+      visit(tree, 'text', function (node) {
+        node.value = typography.exec(node.value)
+      })
+    }
+  }
+
   const promise = Promise.all(
     plugins.map(async function (fn) {
       if (typeof fn === 'string') {
@@ -60,7 +81,7 @@ export default function remarkTextr(options) {
   })
 
   /**
-   * Transform.
+   * Transform asynchronously.
    *
    * @param {Root} tree
    *   Tree.

test.js

@@ -77,6 +77,20 @@ test('remarkTextr', async function (t) {
       'yo «there» …\n'
     )
   })
+
+  t.test('should support syncronous transformer', function () {
+    assert.equal(
+      String(
+        remark()
+          .use(remarkTextr, {
+            plugins: [typographicQuotes],
+            options: {locale: 'ru'}
+          })
+          .processSync('yo "there" \n')
+      ),
+      'yo «there»\n'
+    )
+  })
 })
 
 // Textr plugin: just a function to replace triple dots to ellipses.