The problem

In the most recent version of eslint-config-react-app, which gives support to ESLint 6.x, the dependencies versions are incorrect.

If you see in eslint-config-react-app's package.json file, the required ESLint version should be in the 6th major release range:

https://github.com/facebook/create-react-app/blob/24780bbc608810d874575791bffeb0148e311fef/packages/eslint-config-react-app/package.json#L21

But in this same dependency tree, we also have the need of @typescript-eslint/parser and @typescript-eslint/eslint-plugin packages, both in the 1.x version range.

The problem is: both @typescript-eslint/parser and @typescript-eslint/eslint-plugin in the 1.x version range (the version that eslint-config-react-app uses) do not support ESLint 6.x. You can it in the following links:

• https://github.com/typescript-eslint/typescript-eslint/blob/c367b34abd8c58eddd2c15685ed8c17b983f0da1/packages/eslint-plugin/package.json#L57

• https://github.com/typescript-eslint/typescript-eslint/blob/c367b34abd8c58eddd2c15685ed8c17b983f0da1/packages/parser/package.json#L41

The solution

I suggest that we upgrade @typescript-eslint/parser and @typescript-eslint/eslint-plugin to its latest major release (2.x), which supports ESLint 6.x.

PS: I think that this problem is causing some issues with the create-react-app preflight checks.