1 files changed, 87 insertions, 0 deletions
diff --git a/src/markdownit/splitMixedLists.js b/src/markdownit/splitMixedLists.js
new file mode 100644
index 000000000..cb709af33
--- /dev/null
+++ b/src/markdownit/splitMixedLists.js
@@ -0,0 +1,87 @@
+/*
+ * @copyright Copyright (c) 2022 Max <max@nextcloud.com>
+ *
+ * @author Max <max@nextcloud.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * @param {object} md Markdown object
+ */
+export default function splitMixedLists(md) {
+	md.core.ruler.after('github-task-lists', 'split-mixed-task-lists', state => {
+		const tokens = state.tokens
+
+		for (let i = 0; i < tokens.length; i++) {
+			const token = tokens[i]
+			if (token.attrGet('class') !== 'contains-task-list') {
+				continue
+			}
+			const firstChild = tokens[i + 1]
+			const startsWithTask = firstChild.attrGet('class') === 'task-list-item'
+			if (!startsWithTask) {
+				token.attrs.splice(token.attrIndex('class'))
+				if (token.attrs.length === 0) {
+					token.attrs = null
+				}
+			}
+			const splitBefore = findChildOf(tokens, i, child => {
+				return child.nesting === 1
+					&& child.attrGet('class') !== firstChild.attrGet('class')
+			})
+			if (splitBefore > i) {
+				splitListAt(tokens, splitBefore, state.Token)
+			}
+		}
+
+		return false
+	})
+}
+
+/**
+ * @param {Array} tokens - all the tokens in the doc
+ * @param {number} index - index into the tokens array where to split
+ * @param {object} TokenConstructor - constructor provided by Markdown-it
+ */
+function splitListAt(tokens, index, TokenConstructor) {
+	const closeList = new TokenConstructor('bullet_list_close', 'ul', -1)
+	closeList.block = true
+	const openList = new TokenConstructor('bullet_list_open', 'ul', 1)
+	openList.attrSet('class', 'contains-task-list')
+	openList.block = true
+	tokens.splice(index, 0, closeList, openList)
+}
+
+/**
+ * @param {Array} tokens - all the tokens in the doc
+ * @param {number} parentIndex - index of the parent in the tokens array
+ * @param {Function} predicate - test function returned child needs to pass
+ */
+function findChildOf(tokens, parentIndex, predicate) {
+	const searchLevel = tokens[parentIndex].level + 1
+	for (let i = parentIndex + 1; i < tokens.length; i++) {
+		const token = tokens[i]
+		if (token.level < searchLevel) {
+			return -1
+		}
+		if ((token.level === searchLevel) && predicate(tokens[i])) {
+			return i
+		}
+	}
+	return -1
+}