Ignore commonly generated folders

I think all entries in .gitignore should be ignored by Prettier without the need to specify --ignore-path .gitignore. The .gitignore should be a constant with the option to additionally use a .prettierignore. I think this is sensible because I cannot think of a reason as to why a file that is not version controlled would need to be formatted. With this, many projects may not even need to add a .prettierignore. A .prettierignore is particularly useful for ignoring files that are version controlled because that cannot be done with a .gitignore.

I think it’s safe to say that eventually Prettier will face the same requests from the community as ESLint did. So I suggest following ESLint’s ignore features: https://eslint.org/docs/user-guide/configuring#ignoring-files-and-directories

Specifically:

• Supporting –ignore-pattern CLI command (can be used multiple times) to add custom ignore patterns on top of the ones from --ignore-path.
  • This is useful for running Prettier without needing to add config files.
  • e.g. npx prettier --ignore-pattern ... would be really nice.
  • But this is not comfortable when you have many patterns you want to ignore, and would require extra integration from IDE’s (otherwise “Format On Save” could format a file we want to ignore).
  • Another interesting use case: Un-ignore a pattern, thus force formatting files that are usually ignored (e.g. “Format this file with Prettier” command in IDE’s doesn’t work without it if the file is ignored elsewhere).
• Supporting ignorePatterns property in Prettier configurations.
  • In ESLint, this one took several years of discussions and tickets from the community until they were finally convinced to add it.
  • This essentially solves most custom ignore use cases, as Prettier already uses the config no matter how you run it. So IDE support is out-of-the-box.
• /* prettier-disable */ block comment at the top of the file (Disabling Rules with Inline Comments)
  • Mentioned in https://github.com/prettier/prettier/issues/3634#issuecomment-585261717
• Worth mentioning they also have –no-ignore

An alternative would be to always include .prettierignore and let --ignore-path merge on top of that. Or support several --ignore-path commands. But that would be confusing IMO.