EXTEND_ESLINT=true not working

[Barik85]

Describe the bug

I created .env file in root directory with EXTEND_ESLINT=true
then created .eslint.json file with my config for eslint
but while running npm start this config doesn't work!
So I had to run npm run eject
in file '/config/webpack.config.js' on the line 38 I have found
const isExtendingEslintConfig = process.env.EXTEND_ESLINT === 'true';
but this variable never used.
So on line 339 I just added useEslintrc: isExtendingEslintConfig, and it begans work correctly!

            {
              options: {
                cache: true,
                formatter: require.resolve('react-dev-utils/eslintFormatter'),
                eslintPath: require.resolve('eslint'),
                resolvePluginsRelativeTo: __dirname,
                useEslintrc: isExtendingEslintConfig,
              },
              loader: require.resolve('eslint-loader'),
            },
          ],

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Environment

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Steps to reproduce

1. npx create-react-app my-app --template typescript
2. add .env file in root directory with EXTEND_ESLINT=true
3. add .eslint.json with some rules, for example "react/jsx-props-no-spreading": [0]
4. Try to check if the rule is working. In my case it's not!

Expected behavior

Expect it will consider rules from .eslintrc.json

Actual behavior

Ignoring rules from .eslintrc.json

Reproducible demo

(Paste the link to an example project and exact instructions to reproduce the issue.)

[mrmckeb]

I'll take a look at this for you in the coming days.

[mrmckeb]

Hi @Barik85,

I see that code is used, but removed on eject.

create-react-app/packages/react-scripts/config/webpack.config.js

Lines 364 to 370 in f5c3bdb

	ignore: isExtendingEslintConfig,
	baseConfig: isExtendingEslintConfig
	? undefined
	: {
	extends: [require.resolve('eslint-config-react-app')],
	},
	useEslintrc: isExtendingEslintConfig,

The issue in your case seems to be that you used .eslint.json, as it works for me with .eslintrc.json - but if that's not the case, please re-open with a small reproduction and I'll dig deeper :)

[GapMAX]

Hi @Barik85,

I see that code is used, but removed on eject.

create-react-app/packages/react-scripts/config/webpack.config.js

Lines 364 to 370 in f5c3bdb

	ignore: isExtendingEslintConfig,
	baseConfig: isExtendingEslintConfig
	? undefined
	: {
	extends: [require.resolve('eslint-config-react-app')],
	},
	useEslintrc: isExtendingEslintConfig,

The issue in your case seems to be that you used .eslint.json, as it works for me with .eslintrc.json - but if that's not the case, please re-open with a small reproduction and I'll dig deeper :)

Why removed it on eject?