Summary

In f09e296, offset property is added to Node.Position. But, the property is wrong value in some cases. The offset is 1 larger than expected.

Reproduction

• https://stackblitz.com/edit/stackblitz-starters-6ycx24v4?file=index.ts&view=editor

import { Declaration, parse, Rule } from 'postcss';

const css = parse('a { one: X }');
const a = css.first as Rule;
let one = a.first as Declaration;

console.log(css.source?.end); // ok
console.log(a.source?.end); // NG
console.log(one.source?.end); // NG

$ npm start

> start
> ts-node index.ts

{ column: 13, line: 1, offset: 12 }
{ column: 12, line: 1, offset: 12 }
{ column: 10, line: 1, offset: 10 }

Expected Behavior

The following will be output:

$ npm start

> start
> ts-node index.ts

{ column: 13, line: 1, offset: 12 }
{ column: 12, line: 1, offset: 11 }
{ column: 10, line: 1, offset: 9 }

Additional Information

• I discovered this behavior while working on Add CssSyntaxError.offset and CssSyntaxError.endOffset #2022.
• I can send a pull request to fix it.