ESLint not included by default

[cmacdonnacha]

Hey,

When I create a new app it doesn't include ESLint, is it supposed to?

npx create-react-app my-cra-app

[ghost]

Projects created using Create React App have linting with ESLint already working and configured out of the box with sensible defaults.

[cmacdonnacha]

Great thanks for that info. Just curios, what does extending react-app and react-app/jest achieve? I was under the impression it would use the CRA eslint config, if that is the case do I still take complete ownership of my linting since I extend those two?

[npetruzzelli]

With eslint you can leave off the eslint-config- part of a shareable config's name. What is actually being extended is the config that CRA uses: eslint-config-react-app

• react-app = https://github.com/facebook/create-react-app/blob/v4.0.3/packages/eslint-config-react-app/index.js
• react-app/jest = https://github.com/facebook/create-react-app/blob/v4.0.3/packages/eslint-config-react-app/jest.js

[npetruzzelli]

By take ownership, I mean that CRA won't be responsible for any problems from conflicting or misconfigured rules that you may add. CRA is only responsible for what is in their sharable config. This can happen if you are new to eslint or as more eslint plugins are added to your config.

[ghost]

A configuration file, once extended, can inherit all the traits of another configuration file (including rules, plugins, and language options) and modify all the options. As a result, there are three configurations, as defined below:

• Base config: the configuration that is extended.
• Derived config: the configuration that extends the base configuration.
• Resulting actual config: the result of merging the derived configuration into the base configuration.

Find out more about extending configuration files here.

[cmacdonnacha]

Great thanks @npetruzzelli @harshcut that explains it perfectly.