-
-
Notifications
You must be signed in to change notification settings - Fork 70
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
New: Configuring Additional Lint Targets with
.eslintrc (#20)
Co-Authored-By: Teddy Katz <teddy.katz@gmail.com>
- Loading branch information
1 parent
e02058a
commit f1fe954
Showing
1 changed file
with
123 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,123 @@ | ||
| - Start Date: 2019-05-12 | ||
| - RFC PR: https://github.com/eslint/rfcs/pull/20 | ||
| - Authors: Toru Nagashima ([@mysticatea](https://github.com/mysticatea)) | ||
|
|
||
| # Configuring Additional Lint Targets with `.eslintrc` | ||
|
|
||
| ## Summary | ||
|
|
||
| This proposal adds the ability to specify additional target files into configuration files. This enhancement will solve the pain that people have to use the `--ext` option with wanted file extensions even if they use plugins which support additional file types. | ||
|
|
||
| ## Motivation | ||
|
|
||
| People have to use the `--ext` option or glob patterns to check wanted files even if they use plugins which support additional file types. | ||
|
|
||
| ```yml | ||
| plugins: | ||
| - markdown | ||
| - html | ||
| - "@typescript-eslint" | ||
| - react | ||
| - vue | ||
| ``` | ||
| ```bash | ||
| # ESLint checks only `*.js`. | ||
| eslint src docs | ||
|
|
||
| # Needs `--ext` option | ||
| eslint src docs --ext .js,.md,.html,.ts,.jsx,.tsx,.vue | ||
| ``` | ||
|
|
||
| However, using plugins which support additional file types is the intention that wants to check those files. The requirement of redundant CLI options is not reasonable. | ||
|
|
||
| Per "[Related Discussions](#related-discussions)" section, this is very regularly requested; I want to configure additional target files with `.eslintrc`. | ||
|
|
||
| ## Detailed Design | ||
|
|
||
| This proposal enhances `overrides` property of the config file. | ||
|
|
||
| - If a config file in a directory has `overrides` property, ESLint checks the files which are matched by any of override entries (i.e., `files`/`excludedFiles` criteria) additionally in the directory. | ||
| - If any of `files` value of an override entry ended with `*`, this enhancement doesn't use the entry in order to avoid checking too many kinds of files. | ||
| - This enhancement affects only the case where a directory path is provided on the CLI. If people provide glob patterns on the CLI, ESLint behaves the same as currently. | ||
| - The `--ext` option precedences this enhancement. If the `--ext` option was given, this enhancement is disabled. So people can use the current behavior by `--ext .js`. | ||
| - The ignoring configuration (`.eslintignore`) precedences this enhancement. If `.eslintignore` contains the additional target files, ESLint just ignores those as same as currently. | ||
|
|
||
| The `overrides` property means that people intend to check those files. So this behavior is intuitive. | ||
|
|
||
| <table><td> | ||
| 💡 <b>Example</b>: | ||
| <pre lang="yml"> | ||
| overrides: | ||
| - files: "*.ts" | ||
| parser: "@typescript-eslint/parser" | ||
| - files: "tests/**/*" | ||
| env: { mocha: true } | ||
| </pre> | ||
|
|
||
| With the above config, `eslint .` command will check `*.ts` files additionally. But the command doesn't check all files inside `tests` directory. | ||
| </td></table> | ||
|
|
||
| ### Code blocks | ||
|
|
||
| If a code block that processors extracted has the virtual filename, ESLint filters the file extension of the virtual filename with `--ext` option. This enhancement affects to that check. ESLint lints the code block if the `overrides` matches the virtual filename. | ||
|
|
||
| ### Legacy file extension processors | ||
|
|
||
| This enhancement **doesn't** affect legacy file extension processors. This means that `plugins` property in config files never changes the kinds of target files. | ||
|
|
||
| On the other hand, `extends` property in config files can change the kinds of target files by the `overrides` property in the shareable configs. | ||
|
|
||
| ### Implementation | ||
|
|
||
| - For files, we can add the check to [lib/cli-engine/file-enumerator.js#L410](https://github.com/eslint/eslint/blob/553795712892c8350b1780e947f65d3c019293a7/lib/cli-engine/file-enumerator.js#L410). | ||
| - For code blocks, we can add the check to [lib/cli-engine/cli-engine.js#L248](https://github.com/eslint/eslint/blob/21f3131aa1636afa8e5c01053e0e870f968425b1/lib/cli-engine/cli-engine.js#L248). | ||
|
|
||
| ## Documentation | ||
|
|
||
| This enhancement needs migration guide because of a breaking change. | ||
|
|
||
| - If your config contains `overrides` property, `eslint` command with directory paths lints the files which are matched automatically. This may increase errors of your command.<br> | ||
| If you don't want to add file types to check, please use glob patterns instead of directory paths or `--ext .js` option. | ||
|
|
||
| This enhancement, so it needs to update some documents. | ||
|
|
||
| - In the description of `--ext` CLI option, it should say that your config file may add file types automatically. | ||
| - In the description of `overrides` property, it should say that the `overrides[].files` property adds target files automatically. | ||
|
|
||
| ## Drawbacks | ||
|
|
||
| - This is a breaking change. | ||
| - Implicit behavior may be confusing people. | ||
|
|
||
| ## Backwards Compatibility Analysis | ||
|
|
||
| In the following situation, `eslint` command increases errors. | ||
|
|
||
| - Their configuration has `overrides` property (with `files` property which doesn't end with `*`). | ||
| - Their `eslint` command is using directory paths without `--ext` option. | ||
|
|
||
| I guess that the impact is limited because people use `--ext` option or glob patterns if they use configuration which affects files other than `*.js`. | ||
|
|
||
| ## Alternatives | ||
|
|
||
| - To add `extensions` property that behaves as same as `--ext` option. Explicit reduces confusion. However, plugins and shareable configs cannot add the `extensions` property without the breaking change that drops old ESLint support. | ||
|
|
||
| ## Open Questions | ||
|
|
||
| - | ||
|
|
||
| ## Frequently Asked Questions | ||
|
|
||
| - | ||
|
|
||
| ## Related Discussions | ||
|
|
||
| - [eslint/eslint#801](https://github.com/eslint/eslint/issues/801) - Configurable Extension Filter | ||
| - [eslint/eslint#1674](https://github.com/eslint/eslint/issues/1674) - Allow setting file extensions in .eslintrc | ||
| - [eslint/eslint#2274](https://github.com/eslint/eslint/issues/2274) - Configure file extensions in .eslintrc | ||
| - [eslint/eslint#2419](https://github.com/eslint/eslint/issues/2419) - Allow configuration of default JS file types | ||
| - [eslint/eslint#7324](https://github.com/eslint/eslint/issues/7324) - File extensions in .eslintrc | ||
| - [eslint/eslint#8399](https://github.com/eslint/eslint/issues/8399) - Add .jsx to the default --ext extensions list | ||
| - [eslint/eslint#10828](https://github.com/eslint/eslint/issues/10828) - Support specifying extensions in the config | ||
| - [eslint/eslint#11223](https://github.com/eslint/eslint/issues/11223) - Add --ext to `eslintrc` or other config files |