eslint/docs/src/user-guide/configuring/ignoring-code.md

   1 ---
   2 title: Ignoring Code
   3 layout: doc
   4 eleventyNavigation:
   5     key: ignoring code
   6     parent: configuring
   7     title: Ignoring Code
   8     order: 5
   9
  10 ---
  11
  12 ## `ignorePatterns` in Config Files
  13
  14 You can tell ESLint to ignore specific files and directories using `ignorePatterns` in your config files. `ignorePatterns` patterns follow the same rules as `.eslintignore`. Please see the [the `.eslintignore` file documentation](./ignoring-code#the-eslintignore-file) to learn more.
  15
  16 ```json
  17 {
  18     "ignorePatterns": ["temp.js", "**/vendor/*.js"],
  19     "rules": {
  20         //...
  21     }
  22 }
  23 ```
  24
  25 * Glob patterns in `ignorePatterns` are relative to the directory that the config file is placed in.
  26 * You cannot write `ignorePatterns` property under `overrides` property.
  27 * Patterns defined in `.eslintignore` take precedence over the `ignorePatterns` property of config files.
  28
  29 If a glob pattern starts with `/`, the pattern is relative to the base directory of the config file. For example, `/foo.js` in `lib/.eslintrc.json` matches to `lib/foo.js` but not `lib/subdir/foo.js`.
  30
  31 If a config is provided via the `--config` CLI option, the ignore patterns that start with `/` in the config are relative to the current working directory rather than the base directory of the given config. For example, if `--config configs/.eslintrc.json` is present, the ignore patterns in the config are relative to `.` rather than `./configs`.
  32
  33 ## The `.eslintignore` File
  34
  35 You can tell ESLint to ignore specific files and directories by creating an `.eslintignore` file in your project's root directory. The `.eslintignore` file is a plain text file where each line is a glob pattern indicating which paths should be omitted from linting. For example, the following will omit all JavaScript files:
  36
  37 ```text
  38 **/*.js
  39 ```
  40
  41 When ESLint is run, it looks in the current working directory to find an `.eslintignore` file before determining which files to lint. If this file is found, then those preferences are applied when traversing directories. Only one `.eslintignore` file can be used at a time, so `.eslintignore` files other than the one in the current working directory will not be used.
  42
  43 Globs are matched using [node-ignore](https://github.com/kaelzhang/node-ignore), so a number of features are available:
  44
  45 * Lines beginning with `#` are treated as comments and do not affect the ignore patterns.
  46 * Paths are relative to the current working directory. This is also true of paths passed in via the `--ignore-pattern` [command](../command-line-interface#--ignore-pattern).
  47 * Lines preceded by `!` are negated patterns that re-include a pattern that was ignored by an earlier pattern.
  48 * Ignore patterns behave according to the `.gitignore` [specification](https://git-scm.com/docs/gitignore).
  49
  50 Of particular note is that like `.gitignore` files, all paths used as patterns for both `.eslintignore` and `--ignore-pattern` must use forward slashes as their path separators.
  51
  52 ```text
  53 # Valid
  54 /root/src/*.js
  55
  56 # Invalid
  57 \root\src\*.js
  58 ```
  59
  60 Please see [`.gitignore`](https://git-scm.com/docs/gitignore)'s specification for further examples of valid syntax.
  61
  62 In addition to any patterns in the `.eslintignore` file, ESLint always follows a couple of implicit ignore rules even if the `--no-ignore` flag is passed. The implicit rules are as follows:
  63
  64 * `node_modules/` is ignored.
  65 * dot-files (except for `.eslintrc.*`), as well as dot-folders and their contents, are ignored.
  66
  67 There are also some exceptions to these rules:
  68
  69 * If the path to lint is a glob pattern or directory path and contains a dot-folder, all dot-files and dot-folders will be linted. This includes dot-files and dot-folders that are buried deeper in the directory structure.
  70
  71   For example, `eslint .config/` will lint all dot-folders and dot-files in the `.config` directory, including immediate children as well as children that are deeper in the directory structure.
  72
  73 * If the path to lint is a specific file path and the `--no-ignore` flag has been passed, ESLint will lint the file regardless of the implicit ignore rules.
  74
  75   For example, `eslint .config/my-config-file.js --no-ignore` will cause `my-config-file.js` to be linted. It should be noted that the same command without the `--no-ignore` line will not lint the `my-config-file.js` file.
  76
  77 * Allowlist and denylist rules specified via `--ignore-pattern` or `.eslintignore` are prioritized above implicit ignore rules.
  78
  79   For example, in this scenario, `.build/test.js` is the desired file to allowlist. Because all dot-folders and their children are ignored by default, `.build` must first be allowlisted so that eslint becomes aware of its children. Then, `.build/test.js` must be explicitly allowlisted, while the rest of the content is denylisted. This is done with the following `.eslintignore` file:
  80
  81   ```text
  82   # Allowlist 'test.js' in the '.build' folder
  83   # But do not allow anything else in the '.build' folder to be linted
  84   !.build
  85   .build/*
  86   !.build/test.js
  87   ```
  88
  89   The following `--ignore-pattern` is also equivalent:
  90
  91   ```shell
  92   eslint --ignore-pattern '!.build' --ignore-pattern '.build/*' --ignore-pattern '!.build/test.js' parent-folder/
  93   ```
  94
  95 ## Using an Alternate File
  96
  97 If you'd prefer to use a different file than the `.eslintignore` in the current working directory, you can specify it on the command line using the `--ignore-path` option. For example, you can use `.jshintignore` file because it has the same format:
  98
  99 ```shell
 100 eslint --ignore-path .jshintignore file.js
 101 ```
 102
 103 You can also use your `.gitignore` file:
 104
 105 ```shell
 106 eslint --ignore-path .gitignore file.js
 107 ```
 108
 109 Any file that follows the standard ignore file format can be used. Keep in mind that specifying `--ignore-path` means that any existing `.eslintignore` file will not be used. Note that globbing rules in `.eslintignore` follow those of `.gitignore`.
 110
 111 ## Using eslintIgnore in package.json
 112
 113 If an `.eslintignore` file is not found and an alternate file is not specified, ESLint will look in package.json for an `eslintIgnore` key to check for files to ignore.
 114
 115 ```json
 116 {
 117     "name": "mypackage",
 118     "version": "0.0.1",
 119     "eslintConfig": {
 120         "env": {
 121             "browser": true,
 122             "node": true
 123         }
 124     },
 125     "eslintIgnore": ["hello.js", "world.js"]
 126 }
 127 ```
 128
 129 ## Ignored File Warnings
 130
 131 When you pass directories to ESLint, files and directories are silently ignored. If you pass a specific file to ESLint, then you will see a warning indicating that the file was skipped. For example, suppose you have an `.eslintignore` file that looks like this:
 132
 133 ```text
 134 foo.js
 135 ```
 136
 137 And then you run:
 138
 139 ```shell
 140 eslint foo.js
 141 ```
 142
 143 You'll see this warning:
 144
 145 ```text
 146 foo.js
 147   0:0  warning  File ignored because of a matching ignore pattern. Use "--no-ignore" to override.
 148
 149 ✖ 1 problem (0 errors, 1 warning)
 150 ```
 151
 152 This message occurs because ESLint is unsure if you wanted to actually lint the file or not. As the message indicates, you can use `--no-ignore` to omit using the ignore rules.
 153
 154 Consider another scenario where you may want to run ESLint on a specific dot-file or dot-folder, but have forgotten to specifically allow those files in your `.eslintignore` file. You would run something like this:
 155
 156 ```shell
 157 eslint .config/foo.js
 158 ```
 159
 160 You would see this warning:
 161
 162 ```text
 163 .config/foo.js
 164   0:0  warning  File ignored by default.  Use a negated ignore pattern (like "--ignore-pattern '!<relative/path/to/filename>'") to override
 165
 166 ✖ 1 problem (0 errors, 1 warning)
 167 ```
 168
 169 This message occurs because, normally, this file would be ignored by ESLint's implicit ignore rules (as mentioned above). A negated ignore rule in your `.eslintignore` file would override the implicit rule and reinclude this file for linting. Additionally, in this specific case, `--no-ignore` could be used to lint the file as well.