import assert from "node:assert/strict";
import test from "node:test";
import { mergeStreamingText } from "../src/channels/feishu/streaming-card.js";

test("mergeStreamingText prefers progressive full-text updates", () => {
  assert.equal(mergeStreamingText("", "hel"), "hel");
  assert.equal(mergeStreamingText("hel", "hello"), "hello");
  assert.equal(mergeStreamingText("hello", "hello world"), "hello world");
});

test("mergeStreamingText merges overlapping chunks without duplicating suffixes", () => {
  assert.equal(mergeStreamingText("hello", "lo world"), "hello world");
  assert.equal(mergeStreamingText("abc", "bcdef"), "abcdef");
});