shared-settings.md

Shared Settings

The following options can be set by shared settings. Several rules have the same option, but we can set this option at once.

eslint-plugin-n reads both the node, and the n settings to allow for backward compatibility with eslint-plugin-node.

version

This rule reads the [engines] field of package.json but, you can overwrite the version by version option.

The version option accepts the valid version range of node-semver.

Example version

{ "version": ">= 14" }

Default version

{ "version": ">= 16.0.0" }

allowModules

Some platforms have additional embedded modules. For example, Electron has electron module.

We can specify additional embedded modules with this option. This option is an array of strings as module names.

Example allowModules

{ "allowModules": ["electron"] }

Default allowModules

{ "allowModules": [] }

resolvePaths

Adds additional paths to try for when resolving imports. If a path is relative, it will be resolved from CWD.

Example resolvePaths

{ "resolvePaths": ["/path/to/somewhere", "../relative/path"] }

Default resolvePaths

{ "resolvePaths": [] }

convertPath

If we use transpilers (e.g. Babel), perhaps the file path to a source code is never published. convertPath option tells to the rule, it needs to convert file paths.

This option has two shapes:

type ConvertPathObject = {
  [includedFiles: string]: [ pattern: string, replacement: string ]
}

type ConvertPathArray = {
  include: string[],
  exclude?: string[],
  replace: [ pattern: string, replacement: string ]
}[]

All replacements use the following code:

path.replace(new RegExp(pattern), replacement);

This means the following replacements are permitted:

Pattern	Inserts
$$	Inserts a "$".
$&	Inserts the matched substring.
$`	Inserts the portion of the string that precedes the matched substring.
$'	Inserts the portion of the string that follows the matched substring.
$n	Inserts the nth (1-indexed) capturing group where n is a positive integer less than 100.
$<Name>	Inserts the named capturing group where Name is the group name.

convertPath - Object

This option has the following shape: <targetFiles>: [<pattern>, <replacement>]

• targetFiles is a glob pattern matching linted files
• pattern is a string escaped regex we pass to new RegExp
• replacement is the replacement string.

Example convertPath - Object

So in this example, src/bin/index.js is handled as bin/index.js.

{ "convertPath": {
  "src/bin/**/*.js": ["^src/bin/(.+)$", "bin/$1"]
} }

convertPath - Array

This option has the following shape: { include: <includedFiles>, exclude: <excludedFiles>, replace: [<pattern>, <replacement>] }

• includedFiles is a glob pattern matching linted files
• excludedFiles is a glob pattern matching files in includedFiles that we want to exclude
• pattern is a string escaped regex we pass to new RegExp
• replacement is the replacement string.

Example 1 - Basics

So in this example, src/bin/index.js is handled as bin/index.js.

{ "convertPath": [
  {
    "include": ["src/bin/**/*.js"],
    "replace": ["^src/bin/(.+)$", "bin/$1"]
  }
] }

Example 2 - Exclude specs

So in this example, src/bin/index.js is handled as bin/index.js but, we exclude all .spec.js from the conversion.

{ "convertPath": [
  {
    "include": ["src/bin/**/*.js"],
    "exclude": ["**/*.spec.js"],
    "replace": ["^src/bin/(.+)$", "bin/$1"]
  }
] }

tryExtensions

When an import path does not exist, this rule checks whether or not any of path.js, path.json, and path.node exists. tryExtensions option is the extension list this rule uses at the time.

Example tryExtensions

In this example we only allow the .js, and .ts extensions to be tried.

{ "tryExtensions": [ ".js", ".ts" ] }

Default tryExtensions

{ "tryExtensions": [ ".js", ".json", ".node" ] }

tsconfigPath

Adds the ability to specify the tsconfig used by the typescriptExtensionMap tool.

Example absolute tsconfigPath

{ "tsconfigPath": "/path/to/tsconfig.json" }

Example relative tsconfigPath

{ "tsconfigPath": "./.tsconfig/development.json" }

Default tsconfigPath

By default the tsconfigPath is searched for up the file tree from the currently linted file.

typescriptExtensionMap

Adds the ability to change the extension mapping when converting between typescript and javascript

You can also use the typescript compiler jsx options to automatically use the correct mapping.

We perform the following checks to work out what your ts extension mappings should be:

1. This checks options.typescriptExtensionMap, if its an array then it gets returned.
2. This checks options.typescriptExtensionMap, if its a string, convert to the correct mapping.
3. This checks options.tsconfigFile, if its set it check for a compilerOptions.jsx property
4. This checks settings.typescriptExtensionMap, if its an array then it gets returned.
5. This checks settings.typescriptExtensionMap, if its a string, convert to the correct mapping.
6. This checks settings.tsconfigFile, if its set it check for a compilerOptions.jsx property
7. This tries to find the closest tsconfig.json, then checks for a compilerOptions.jsx property
8. This returns PRESERVE_MAPPING.

Example - Custom react mappings

{ "typescriptExtensionMap": [
    [ "", ".js" ],
    [ ".ts", ".js" ],
    [ ".cts", ".cjs" ],
    [ ".mts", ".mjs" ],
    [ ".tsx", ".js" ],
] }

Example - Wordy react mappings

{ "typescriptExtensionMap": "react" }

Default typescriptExtensionMap

If we cannot find a tsconfig file, we fall back to using:

{ "typescriptExtensionMap": "preserve" }