Separate ESLint and Prettier configurations

[s-kawabe]

Why

Currently, the frolint command is set up to run Prettier integrated with ESLint.

What this means is that you can use the eslint-plugin-prettier plugin to run formater as if it were acting as a linter. This has the following concerns and ideas, which we believe should be quit in this day and age. 🤔

Idea

• When eslint-plugin-prettier was recommended, many of the editors did not support Prettier, and the idea was that you had no choice but to use them via ESLint. However, many modern editors support Prettier execution, so this concern is almost no longer a concern.

Concerns

• Running Prettier on ESLint slows it down.
• In order to run Prettier on ESLint, you need to put a layer between them, which may lead to unintended behavior.
• linter and formatter are not separated, leading to unintentional warnings in the format context as a linter warning.

The Prettier formula also recommends that in the modern era it be run alone, not on ESLint. https://prettier.io/docs/en/integrating-with-linters.html#notes

First, we have plugins that let you run Prettier as if it was a linter rule:

• eslint-plugin-prettier
• stylelint-prettier These plugins were especially useful when Prettier was new. By running Prettier inside your linters, you didn’t have to set up any > new infrastructure and you could re-use your editor integrations for the linters. But these days you can run prettier --check . and most editors have Prettier support.

What

Remove eslint-plugin-prettier so that Prettier runs by itself.

(This change is not disruptive to the developer experience for frolint users.)