fix(markdown): split mixed task and bullet lists

web/src/components/MemoContent/index.tsx

@@ -14,6 +14,7 @@ import { rehypeHeadingId } from "@/utils/rehype-plugins/rehype-heading-id";
 import { remarkDisableSetext } from "@/utils/remark-plugins/remark-disable-setext";
 import { extractMentionUsernames, remarkMention } from "@/utils/remark-plugins/remark-mention";
 import { remarkPreserveType } from "@/utils/remark-plugins/remark-preserve-type";
+import { remarkSplitMixedTaskLists } from "@/utils/remark-plugins/remark-split-mixed-task-lists";
 import { remarkTag } from "@/utils/remark-plugins/remark-tag";
 import { CodeBlock } from "./CodeBlock";
 import { isMentionNode, isTagNode, isTaskListItemNode } from "./ConditionalComponent";
@@ -79,7 +80,16 @@ const MemoContent = (props: MemoContentProps) => {
         onDoubleClick={onDoubleClick}
       >
         <ReactMarkdown
-          remarkPlugins={[remarkDisableSetext, remarkMath, remarkGfm, remarkBreaks, remarkMention, remarkTag, remarkPreserveType]}
+          remarkPlugins={[
+            remarkDisableSetext,
+            remarkMath,
+            remarkGfm,
+            remarkSplitMixedTaskLists,
+            remarkBreaks,
+            remarkMention,
+            remarkTag,
+            remarkPreserveType,
+          ]}
           rehypePlugins={[
             rehypeRaw,
             [rehypeSanitize, SANITIZE_SCHEMA],

web/src/utils/remark-plugins/remark-split-mixed-task-lists.ts

+import type { List, ListItem, Root } from "mdast";
+import type { Parent } from "unist";
+
+const isTaskListItem = (item: ListItem): boolean => typeof item.checked === "boolean";
+
+const splitMixedList = (list: List): List[] => {
+  const hasTaskItem = list.children.some(isTaskListItem);
+  const hasRegularItem = list.children.some((item) => !isTaskListItem(item));
+
+  if (!hasTaskItem || !hasRegularItem) {
+    return [list];
+  }
+
+  const groups: Array<{ isTaskGroup: boolean; items: ListItem[] }> = [];
+  for (const item of list.children) {
+    const isTaskGroup = isTaskListItem(item);
+    const previousGroup = groups.at(-1);
+
+    if (previousGroup && previousGroup.isTaskGroup === isTaskGroup) {
+      previousGroup.items.push(item);
+    } else {
+      groups.push({ isTaskGroup, items: [item] });
+    }
+  }
+
+  return groups.map(({ isTaskGroup, items }) => ({
+    ...list,
+    children: isTaskGroup ? items : items.map((item) => ({ ...item, spread: false })),
+    spread: isTaskGroup ? list.spread : false,
+  }));
+};
+
+const splitMixedTaskListsInParent = (parent: Parent): void => {
+  for (let index = 0; index < parent.children.length; index++) {
+    const child = parent.children[index];
+
+    if ("children" in child && Array.isArray(child.children)) {
+      splitMixedTaskListsInParent(child as Parent);
+    }
+
+    if (child.type !== "list") {
+      continue;
+    }
+
+    const splitLists = splitMixedList(child as List);
+    if (splitLists.length > 1) {
+      parent.children.splice(index, 1, ...splitLists);
+      index += splitLists.length - 1;
+    }
+  }
+};
+
+export const remarkSplitMixedTaskLists = () => {
+  return (tree: Root) => {
+    splitMixedTaskListsInParent(tree);
+  };
+};

web/tests/memo-content-list.test.tsx

+import { renderToStaticMarkup } from "react-dom/server";
+import ReactMarkdown from "react-markdown";
+import remarkGfm from "remark-gfm";
+import { List, ListItem } from "@/components/MemoContent/markdown";
+import { TASK_LIST_CLASS, TASK_LIST_ITEM_CLASS } from "@/components/MemoContent/constants";
+import { remarkSplitMixedTaskLists } from "@/utils/remark-plugins/remark-split-mixed-task-lists";
+import { describe, expect, it } from "vitest";
+
+const renderListContent = (content: string): string =>
+  renderToStaticMarkup(
+    <ReactMarkdown
+      remarkPlugins={[remarkGfm, remarkSplitMixedTaskLists]}
+      components={{
+        ul: ({ children, ...props }) => <List {...props}>{children}</List>,
+        li: ({ children, ...props }) => <ListItem {...props}>{children}</ListItem>,
+      }}
+    >
+      {content}
+    </ReactMarkdown>,
+  );
+
+describe("memo content lists", () => {
+  it("keeps bullets on regular items in mixed task and bullet lists", () => {
+    const html = renderListContent("- [ ] pickup package\n- [ ] library returns\n\n- milk\n- eggs\n- bread");
+    const listOpenTags = html.match(/<ul class="[^"]*"/g) ?? [];
+
+    expect(listOpenTags).toHaveLength(2);
+    expect(listOpenTags[0]).toContain(TASK_LIST_CLASS);
+    expect(listOpenTags[0]).toContain("list-none");
+    expect(listOpenTags[0]).not.toContain("pl-6");
+    expect(listOpenTags[1]).not.toContain(TASK_LIST_CLASS);
+    expect(listOpenTags[1]).toContain("pl-6");
+    expect(listOpenTags[1]).toContain("list-disc");
+    expect(html).toContain('<li class="mt-0.5 leading-6">milk</li>');
+    expect(html).not.toContain('<li class="mt-0.5 leading-6">\n<p>milk</p>');
+    expect(html).toContain(TASK_LIST_ITEM_CLASS);
+  });
+
+  it("keeps compact styling for pure task lists", () => {
+    const html = renderListContent("- [ ] pickup package\n- [ ] library returns");
+
+    expect(html).toMatch(/<ul class="[^"]*\blist-none\b[^"]*"/);
+    expect(html).not.toMatch(/<ul class="[^"]*\blist-disc\b[^"]*"/);
+  });
+});