Support mixed nested lists (#39)

tests/mixed-lists.test.mjs

@@ -0,0 +1,80 @@
+import assert from 'node:assert/strict';
+import { readFile } from 'node:fs/promises';
+import test from 'node:test';
+import { Schema } from '@tiptap/pm/model';
+import { transformWithEsbuild } from 'vite';
+
+const source = await readFile(
+  new URL('../src/lib/editor/mixedLists.ts', import.meta.url),
+  'utf8'
+);
+const { code } = await transformWithEsbuild(source, 'mixedLists.ts', {
+  loader: 'ts',
+  format: 'esm',
+  target: 'esnext'
+});
+const { convertListNode } = await import(
+  `data:text/javascript;base64,${Buffer.from(code).toString('base64')}`
+);
+
+const schema = new Schema({
+  nodes: {
+    doc: { content: 'block+' },
+    paragraph: { content: 'text*', group: 'block' },
+    text: { group: 'inline' },
+    bulletList: { content: 'listItem+', group: 'block' },
+    listItem: { content: 'paragraph block*' },
+    taskList: { content: 'taskItem+', group: 'block' },
+    taskItem: {
+      attrs: { checked: { default: false } },
+      content: 'paragraph block*'
+    }
+  }
+});
+
+function paragraph(text) {
+  return schema.node('paragraph', null, [schema.text(text)]);
+}
+
+test('converts every task item in a list to a bullet item', () => {
+  const sourceList = schema.node('taskList', null, [
+    schema.node('taskItem', { checked: true }, [paragraph('First')]),
+    schema.node('taskItem', { checked: false }, [paragraph('Second')])
+  ]);
+
+  const converted = convertListNode(schema, sourceList, 'bulletList');
+
+  assert.equal(converted.type.name, 'bulletList');
+  assert.deepEqual(
+    converted.content.content.map((item) => item.type.name),
+    ['listItem', 'listItem']
+  );
+  assert.equal(converted.textContent, 'FirstSecond');
+  assert.equal(sourceList.type.name, 'taskList');
+});
+
+test('converts bullet items to unchecked tasks without dropping nested blocks', () => {
+  const nestedBullets = schema.node('bulletList', null, [
+    schema.node('listItem', null, [paragraph('Nested note')])
+  ]);
+  const sourceList = schema.node('bulletList', null, [
+    schema.node('listItem', null, [paragraph('Parent'), nestedBullets])
+  ]);
+
+  const converted = convertListNode(schema, sourceList, 'taskList');
+  const taskItem = converted.firstChild;
+
+  assert.equal(converted.type.name, 'taskList');
+  assert.equal(taskItem.type.name, 'taskItem');
+  assert.equal(taskItem.attrs.checked, false);
+  assert.equal(taskItem.lastChild.type.name, 'bulletList');
+  assert.equal(taskItem.textContent, 'ParentNested note');
+});
+
+test('leaves a list alone when it already has the requested type', () => {
+  const bullets = schema.node('bulletList', null, [
+    schema.node('listItem', null, [paragraph('Unchanged')])
+  ]);
+
+  assert.equal(convertListNode(schema, bullets, 'bulletList'), null);
+});