From e38d67602447bad97b14059d7ab7d3893268a907 Mon Sep 17 00:00:00 2001
From: Yuki Hattori <yukihattori1116@gmail.com>
Date: Sun, 15 Oct 2023 03:10:42 +0900
Subject: [PATCH] Prefer lang global directive than constructor option

---
 src/markdown/directives/apply.js  | 4 ++--
 src/marpit.js                     | 2 ++
 test/markdown/directives/apply.js | 5 +++++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/markdown/directives/apply.js b/src/markdown/directives/apply.js
index 61b3a80..1ce81cd 100644
--- a/src/markdown/directives/apply.js
+++ b/src/markdown/directives/apply.js
@@ -70,8 +70,8 @@ function _apply(md, opts = {}) {
           }
 
           // Apply attribute to token
-          if (lang || marpitDirectives.lang)
-            token.attrSet('lang', lang || marpitDirectives.lang)
+          if (marpitDirectives.lang || lang)
+            token.attrSet('lang', marpitDirectives.lang || lang)
 
           if (marpitDirectives.class)
             token.attrJoin('class', marpitDirectives.class)
diff --git a/src/marpit.js b/src/marpit.js
index 7dbe90c..14a0529 100644
--- a/src/marpit.js
+++ b/src/marpit.js
@@ -72,6 +72,8 @@ class Marpit {
    *     slide page at before of headings. it would apply to headings whose
    *     larger than or equal to the specified level if a number is given, or
    *     ONLY specified levels if a number array.
+   * @param {string} [opts.lang] Set the default `lang` attribute of each slide.
+   *     It can override by `lang` global directive in the Markdown.
    * @param {boolean} [opts.looseYAML=false] Allow loose YAML parsing in
    *     built-in directives, and custom directives defined in current instance.
    * @param {MarkdownIt|string|Object|Array} [opts.markdown] An instance of
diff --git a/test/markdown/directives/apply.js b/test/markdown/directives/apply.js
index 595bc5d..92a84d6 100644
--- a/test/markdown/directives/apply.js
+++ b/test/markdown/directives/apply.js
@@ -120,6 +120,11 @@ describe('Marpit directives apply plugin', () => {
         expect(sections.eq(1).attr('lang')).toBe('en-US')
       })
 
+      it('can override the language that is setting by `lang` constructor option', () => {
+        const $lang = load(md({ options: { lang: 'fr' } }).render(langDir))
+        expect($lang('section').first().attr('lang')).toBe('en-US')
+      })
+
       context('when lang directive is not defined', () => {
         it('follows the lang option of Marpit instance', () => {
           const $ = load(md({}).render(''))