Add React version into eslint-config-react-app

[UnableHead]

Hello everyone,

Is this a bug report?

No

Situation

I'm working on a project that use React (react@15.6.2). I use react-scripts (1.0.11) to start and build my project.

According to my React version, I use some deprecated function:

• componentWillMount (https://reactjs.org/docs/react-component.html#unsafe_componentwillmount)
• componentWillReceiveProps (https://reactjs.org/docs/react-component.html#unsafe_componentwillreceiveprops)

These functions are deprecated in 16.3.0 of React.

Problems

Now, when I start or build my project, I get several warnings inside console and browser for this deprecated function.

Explanation

I try to understand why I got this message for the React 15.6.2 which are not concern by this warning. In fact, the package eslint-config-react-app@2.1.0 set the ESLint configuration for the actions of react-scripts.

The ESLint's plugin eslint-plugin-react have a rule: "react/no-deprecated" that created the warnings. This rule match on deprecated code, according to the configured React version number given in the ESLint config file. But, in this case, eslint-config-react-app does not define React version. So, as explain here: https://github.com/yannickcr/eslint-plugin-react#configuration, the default value is the latest React stable release.

That explain why I got warnings aiming React 16.3 in my project which use React 15.6.2.

Solution

I suggest as solution to define React version in the configuration file of eslint-config-react-app.

I resolve my problem on adding this:

settings: {
  react: {
    version: require('react').version
  }
},

inside the file index.js of eslint-config-react-app.

This solution could have some problems, especially, the package react is now mandatory (we could add a verification if package react exist before).

I know, that I could also "eject" my project and edit the config files, but I think this modification should be helpful for other users.

Discussion

In first time, I enjoy to know if my solution is correct on the content and the style. In second time, if people agree with me, I will create a pull request to integrate this modification inside the project.

Thanks for the reading. I hope that my post is clear enough.

[Timer]

This sounds reasonable -- though I could be convinced either way, @gaearon?