Off-by-one columns in babel/code-frame #17316

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• Would you like to work on a fix?

How are you using Babel?

Programmatic API (babel.transform, babel.parse)

Input code

import {parse} from '@babel/parser';
import {codeFrameColumns} from '@babel/code-frame';

var code = 'x = "foobar";';
var ast = parse(code);
console.error(codeFrameColumns(code, ast.program.body[0].expression.right.loc));

Configuration file name

No response

Configuration

No response

Current and expected behavior

Current output:

> 1 | x = "foobar";
    |    ^^^^^^^^

Expected output:

> 1 | x = "foobar";
    |     ^^^^^^^^

The column is clearly interpreted as 1-based even though Babel AST returns them as 0-based everywhere else, and codeFrameColumns accepts a NodeLocation which suggests it should use a compatible location format:

Environment

npx envinfo --preset babel

System:
OS: Windows 11 10.0.26100
Binaries:
Node: 24.0.0 - C:\Program Files\nodejs\node.EXE
npm: 11.3.0 - C:\Program Files\nodejs\npm.CMD
pnpm: 9.15.5 - ~\AppData\Local\pnpm\pnpm.CMD
npmPackages:
@babel/code-frame: ^7.27.1 => 7.26.2
@babel/core: ^7.27.1 => 7.26.10
@babel/generator: ^7.27.1 => 7.26.10
@babel/parser: ^7.27.1 => 7.26.10
@babel/preset-env: ^7.27.1 => 7.26.9
@babel/types: ^7.27.1 => 7.26.10

Possible solution

No response

Additional context

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