history.test.ts

history.test.tspackages/editor/src/history.test.tsraw ← src2,341 B← Back to the app
1import { describe, expect, it } from "vitest";
2 
3import { History, HISTORY_LIMIT } from "./history.js";
4import type { BlockDto } from "./types.js";
5 
6function block(id: string, text: string, version = 1): BlockDto {
7  return {
8    id,
9    type: "paragraph",
10    content: { text },
11    parentId: null,
12    position: "1",
13    version,
14  };
15}
16 
17describe("History (undo/redo, 100 steps)", () => {
18  it("records, undoes and redoes", () => {
19    const h = new History([block("a", "A")]);
20    expect(h.canUndo).toBe(false);
21    expect(h.canRedo).toBe(false);
22 
23    h.record(h.current(), [block("a", "AB")], "type");
24    expect(h.canUndo).toBe(true);
25    expect(h.depth).toBe(1);
26 
27    const undo = h.undo();
28    expect(undo?.blocks.map((b) => (b.content as { text: string }).text)).toEqual(["A"]);
29    expect(h.canRedo).toBe(true);
30 
31    const redo = h.redo();
32    expect(redo?.blocks.map((b) => (b.content as { text: string }).text)).toEqual(["AB"]);
33    expect(h.canRedo).toBe(false);
34  });
35 
36  it("truncates the redo branch on a new edit after undo", () => {
37    const h = new History([block("a", "A")]);
38    h.record(h.current(), [block("a", "B")], "e1");
39    h.record(h.current(), [block("a", "C")], "e2");
40    h.undo(); // back to B
41    h.record(h.current(), [block("a", "D")], "e3"); // new branch
42    expect(h.canRedo).toBe(false);
43    expect(h.depth).toBe(2);
44  });
45 
46  it("coalesces consecutive same-label steps (typing burst)", () => {
47    const h = new History([block("a", "A")]);
48    h.record(h.current(), [block("a", "AB")], "type");
49    h.record(h.current(), [block("a", "ABC")], "type");
50    expect(h.depth).toBe(1); // one step, not two
51    const undo = h.undo();
52    expect(undo?.blocks.map((b) => (b.content as { text: string }).text)).toEqual(["A"]);
53  });
54 
55  it("caps the undo stack at 100 steps", () => {
56    const h = new History([block("a", "A")]);
57    for (let i = 0; i < HISTORY_LIMIT + 10; i += 1) {
58      h.record(h.current(), [block("a", `T${i}`)], `edit-${i}`);
59    }
60    expect(h.depth).toBe(HISTORY_LIMIT);
61  });
62 
63  it("reset drops all history", () => {
64    const h = new History([block("a", "A")]);
65    h.record(h.current(), [block("a", "B")], "x");
66    h.reset([block("b", "fresh")]);
67    expect(h.canUndo).toBe(false);
68    expect(h.canRedo).toBe(false);
69    expect(h.current().map((b) => b.id)).toEqual(["b"]);
70  });
71});
72