packages/muya/src/selection/__tests__/offsetClamp.spec.ts - develop - githubmirror/marktext

packages/muya/src/selection/__tests__/offsetClamp.spec.ts

62 строки2 KB

Ran Luo

fix(muya): clamp selection offset to the node's legal range (#4575, #4464, #4458) (#4626)

22 июн 2026, 10:22

22 июн 2026, 10:22a1855dd

// @vitest-environment happy-dom

import { describe, expect, it } from 'vitest';
import { getLegalOffset, getNodeAndOffset } from '../dom';

// Regression coverage for the `Failed to execute 'setStart' on 'Range'`
// crashes reported in #4575 / #4464 (offset past the rendered text after a
// re-render) and #4458 (offset 4294967295 = unsigned -1 from a corrupted
// browser selection). The legacy engine clamped the recorded offset to the
// node's legal range before touching the DOM Range API; the rewrite dropped
// that guard. `getLegalOffset` restores it.
describe('getLegalOffset', () => {
    it('clamps a text-node offset to the text length', () => {
        const text = document.createTextNode('abc');

        expect(getLegalOffset(text, 99)).toBe(3);
    });

    it('clamps an element-node offset to childNodes.length', () => {
        const el = document.createElement('span');
        el.appendChild(document.createTextNode('a'));
        el.appendChild(document.createElement('b'));

        expect(getLegalOffset(el, 99)).toBe(2);
    });

    it('coerces a negative offset to 0', () => {
        const text = document.createTextNode('abc');

        expect(getLegalOffset(text, -1)).toBe(0);
    });

    it('clamps the unsigned -1 offset (4294967295) to the text length', () => {
        const text = document.createTextNode('abc');

        expect(getLegalOffset(text, 4294967295)).toBe(3);
    });

    it('leaves an in-range offset unchanged', () => {
        const text = document.createTextNode('abcde');

        expect(getLegalOffset(text, 2)).toBe(2);
    });

    it('produces an offset Range.setStart accepts when getNodeAndOffset overflows', () => {
        const p = document.createElement('p');
        p.appendChild(document.createTextNode('hello'));
        document.body.appendChild(p);

        const { node, offset } = getNodeAndOffset(p, 999);
        const legal = getLegalOffset(node, offset);

        expect(legal).toBeLessThanOrEqual(
            node.nodeType === Node.TEXT_NODE
                ? (node as Text).length
                : node.childNodes.length,
        );
        expect(legal).toBeGreaterThanOrEqual(0);

        p.remove();
    });
});