Help - Diff Plugin not compatible with new flat config

[mlwyatt]

Either this plugin isn't compatible with ESLint's flat config file yet, or I'm not setting it up quite right.

Here's a simple example:

Config

import globals from 'globals';
import diff from 'eslint-plugin-diff';

export default [
  {
    ...diff.configs.diff.overrides[0],
    plugins: { diff },
    processor: diff.processors.diff,
  },
  {
    rules: {
      'no-console': ['error'],
    },
  },
];

console.log(1);
+console.log(2);
console.log(3);
console.log(4);

Expected

  2:1  error  Unexpected console statement  no-console

Actual

  1:1  error  Unexpected console statement  no-console
  2:1  error  Unexpected console statement  no-console
  3:1  error  Unexpected console statement  no-console
  4:1  error  Unexpected console statement  no-console

Any help would be appreciated.
Thanks in advance

[paleite]

Ah, that's interesting. Great find! Do you have a reproduction repository i could check?

[mlwyatt]

Unfortunately, I don't. I was migrating a couple of my work projects, one of which is written in TS, to the flat config but then came across this saying the TS plugin won't be updated until the flat config is almost finished. Once I found out that, I just dropped it and moved on

[alexeyr-ci]

I can say it appears to work for me. The only thing I needed to do is

const { FlatCompat } = require('@eslint/eslintrc');
const js = require('@eslint/js');

const compat = new FlatCompat({
  baseDirectory: __dirname,
  recommendedConfig: js.configs.recommended,
});

module.exports = [
  // what we had previously
  ...compat.extends('plugin:diff/diff'),
];

[Lucasgb7]

Are there any updates about ESLint's flat config support?

[lionmark01]

For me I figured out how to make it work with my setup

My setup

• eslint 9.14.0
• typescript-eslint 8.14.0
• eslint-plugin-diff 2.0.3

My eslint.config.mjs

import diff from 'eslint-plugin-diff';

export default tseslint.config(
  // include some rule
  
  {
    plugins: {
      diff
    },
    processor: diff.processors.diff,
    
    // other config
  }
);

Hope this help !