eslint-loader
Last updated
Last updated
A ESlint loader for webpack
Note: You also need to install eslint
from npm, if you haven't already:
In your webpack configuration:
When using with transpiling loaders (like babel-loader
), make sure they are in correct order (bottom to top). Otherwise files will be checked after being processed by babel-loader
:
To be safe, you can use enforce: 'pre'
section to check source files, not modified by other loaders (like babel-loader
):
You can pass eslint options using standard webpack loader options.
Note that the config option you provide will be passed to the CLIEngine
. This is a different set of options than what you'd specify in package.json
or .eslintrc
. See the eslint docs for more detail.
cache
Type: Boolean|String
Default: false
This option will enable caching of the linting results into a file. This is particularly useful in reducing linting time when doing a full build.
This can either be a boolean
value or the cache directory path(ex: './.eslint-loader-cache'
).
If cache: true
is used, the cache is written to the ./node_modules/.cache/eslint-loader
directory. This is the recommended usage.
eslintPath
Type: String
Default: eslint
Path to eslint
instance that will be used for linting. If the eslintPath
is a folder like a official eslint, or specify a formatter
option. Now you dont have to install eslint
.
fix
Type: Boolean
Default: false
This option will enable ESLint autofix feature.
Be careful: this option will change source files.
formatter
Type: String|Function
Default: stylish
This option accepts a function that will have one argument: an array of eslint messages (object). The function must return the output as a string. You can use official eslint formatters.
By default the loader will auto adjust error reporting depending on eslint errors/warnings counts. You can still force this behavior by using emitError
or emitWarning
options:
emitError
Type: Boolean
Default: false
Will always return errors, if this option is set to true
.
emitWarning
Type: Boolean
Default: false
Will always return warnings, if option is set to true
. If you're using hot module replacement, you may wish to enable this in development, or else updates will be skipped when there's an eslint error.
failOnError
Type: Boolean
Default: false
Will cause the module build to fail if there are any errors, if option is set to true
.
failOnWarning
Type: Boolean
Default: false
Will cause the module build to fail if there are any warnings, if option is set to true
.
quiet
Type: Boolean
Default: false
Will process and report errors only and ignore warnings, if this option is set to true
.
outputReport
Type: Boolean|Object
Default: false
Write the output of the errors to a file, for example a checkstyle xml file for use for reporting on Jenkins CI.
The filePath
is an absolute path or relative to the webpack config: output.path
. You can pass in a different formatter
for the output file, if none is passed in the default/configured formatter will be used.
NoEmitOnErrorsPlugin
is now automatically enabled in webpack 4, when mode is either unset, or set to production. So even ESLint warnings will fail the build. No matter what error settings are used for eslint-loader
, except if emitWarning
enabled.
configFile
or using eslint -c path/.eslintrc
Bear in mind that when you define configFile
, eslint
doesn't automatically look for .eslintrc
files in the directory of the file to be linted. More information is available in official eslint documentation in section Using Configuration Files. See #129.