writing-diff.test.ts

writing-diff.test.tsapps/web/src/lib/__tests__/writing-diff.test.tsraw ← __tests__2,835 B← Back to the app
1/**
2 * TASK-0123 — the diff's OLD-side extractor (`blockPlainText`) + the
3 * word-level diff renderer's input contract (`wordDiff` from @factory/editor).
4 *
5 * The writing diff renders `wordDiff(oldText, newText)` for improve/rewrite/
6 * translate (summarize shows the raw summary). These tests pin the pure
7 * pieces: the extractor across the content model's shapes, and that the
8 * shared diff util produces same/del/add segments that reconstruct BOTH sides
9 * (so the UI can't silently drop or duplicate text).
10 *
11 * @vitest-environment node (no DOM).
12 */
13import { describe, it, expect } from "vitest";
14import { blockPlainText } from "@/lib/ai";
15import { wordDiff, reconstructOld, reconstructNew } from "@factory/editor";
16 
17describe("blockPlainText (the diff's OLD side)", () => {
18  it("reads {text} (the canonical content model)", () => {
19    expect(blockPlainText({ text: "Hello world" })).toBe("Hello world");
20  });
21  it("passes a raw string through (legacy/inline path)", () => {
22    expect(blockPlainText("just a string")).toBe("just a string");
23  });
24  it("falls back to {title}", () => {
25    expect(blockPlainText({ title: "Page title" })).toBe("Page title");
26  });
27  it("prefers {text} over {title}", () => {
28    expect(blockPlainText({ text: "body", title: "head" })).toBe("body");
29  });
30  it("returns '' for null/undefined/non-object", () => {
31    expect(blockPlainText(null)).toBe("");
32    expect(blockPlainText(undefined)).toBe("");
33    expect(blockPlainText(42)).toBe("");
34    expect(blockPlainText({ text: 42 })).toBe("");
35  });
36});
37 
38describe("wordDiff (the diff renderer's input)", () => {
39  it("marks unchanged text as `same`", () => {
40    expect(wordDiff("hello world", "hello world")).toEqual([{ type: "same", text: "hello world" }]);
41  });
42  it("produces add/del segments that reconstruct BOTH sides", () => {
43    const old = "the quick brown fox";
44    const neu = "the slow brown fox";
45    const segs = wordDiff(old, neu);
46    // At least one del (quick) and one add (slow) — the visible diff.
47    expect(segs.some((s) => s.type === "del")).toBe(true);
48    expect(segs.some((s) => s.type === "add")).toBe(true);
49    // The segments must reconstruct the original AND the proposed text, so
50    // the UI can't drop or duplicate words.
51    expect(reconstructOld(segs)).toBe(old);
52    expect(reconstructNew(segs)).toBe(neu);
53  });
54  it("treats a full replacement as all-del + all-add", () => {
55    const segs = wordDiff("alpha beta", "gamma delta");
56    expect(reconstructOld(segs)).toBe("alpha beta");
57    expect(reconstructNew(segs)).toBe("gamma delta");
58    expect(segs.some((s) => s.type === "del")).toBe(true);
59    expect(segs.some((s) => s.type === "add")).toBe(true);
60  });
61  it("returns [] for an empty old text", () => {
62    expect(wordDiff("", "new")).toEqual([{ type: "add", text: "new" }]);
63  });
64});
65