feat: 新增 validateTaskFormat 校验函数

src/core/task-parser.ts

@@ -14,3 +14,22 @@ export function parseTasks(content: string): TaskItem[] {
   }
   return tasks;
 }
+
+export class TaskFormatError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = this.constructor.name;
+  }
+}
+
+export function validateTaskFormat(content: string): void {
+  const tasks = parseTasks(content);
+  if (tasks.length === 0) {
+    throw new TaskFormatError("task.md 必须包含至少一个 checkbox 项");
+  }
+  for (const task of tasks) {
+    if (task.text.trim() === "") {
+      throw new TaskFormatError("task.md 中每个 checkbox 项必须有非空描述");
+    }
+  }
+}