From 5f05818e0e44683ce033110838145aba061f213b Mon Sep 17 00:00:00 2001
From: nobkd <44443899+nobkd@users.noreply.github.com>
Date: Mon, 3 Feb 2025 19:47:01 +0100
Subject: [PATCH] merge and deduplicate class names

---
 packages/nuemark/src/parse-tag.js   | 12 ++++++++----
 packages/nuemark/test/block.test.js |  6 ++++++
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/packages/nuemark/src/parse-tag.js b/packages/nuemark/src/parse-tag.js
index d933d98d..6f8e866b 100644
--- a/packages/nuemark/src/parse-tag.js
+++ b/packages/nuemark/src/parse-tag.js
@@ -10,9 +10,11 @@ export function parseTag(input) {
   const specs = strings.filter((s, i) => !i || s.match(/^[#|.]/)).join('')
   const attribs = strings.filter(s => !specs.includes(s))
   const self = { ...parseSpecs(specs), data: {} }
-
+  const classes = new Set((self.attr?.class || '').split(' '))
 
   function set(key, val) {
+    if (key == 'class') return val.split(' ').forEach(v => classes.add(v))
+
     const ctx = ATTR.includes(key) || key.startsWith('data-') ? 'attr' : 'data'
     self[ctx][key] = val
   }
@@ -30,6 +32,8 @@ export function parseTag(input) {
     else set('_', getValue(key) || key)
   }
 
+  if (classes.size) self.attr.class = [...classes].join(' ')
+
   return self
 }
 
@@ -76,9 +80,9 @@ export function parseAttr(str) {
   const attr = {}
 
   // classes
-  const classes = []
-  str.replace(/\.([\w\-]+)/g, (_, el) => classes.push(el))
-  if (classes[0]) attr.class = classes.join(' ')
+  const classes = new Set()
+  str.replace(/\.([\w\-]+)/g, (_, el) => classes.add(el))
+  if (classes.size) attr.class = [...classes].join(' ')
 
   // id
   str.replace(/#([\w\-]+)/, (_, el) => attr.id = el)
diff --git a/packages/nuemark/test/block.test.js b/packages/nuemark/test/block.test.js
index be302ace..bd43c492 100644
--- a/packages/nuemark/test/block.test.js
+++ b/packages/nuemark/test/block.test.js
@@ -233,6 +233,12 @@ test('complex tag data', () => {
   expect(comp.data).toEqual({ world: true, size: 10, foo: "bar", })
 })
 
+test('duplicate tag classes', () => {
+  const { blocks } = parseBlocks(['[hello.c.c.bar class="foo bar" world]'])
+  expect(blocks[0].attr.class).toBe('c bar foo')
+  expect(blocks[0].data).toEqual({ world: true })
+})
+
 test('escaping', () => {
   const html = renderLines([
     '\\[code]', '',