The plugin helps to unify imports style via compile warnings/errors
Tested with:
- 9.2.7
- 9.4.8
- 9.6.4
- 9.8.2
build-depends: ..., import-style-plugin, ...
ghc-options: -fplugin ImportStylePlugin.Yaml -fplugin-opt ImportStylePlugin.Yaml:<path-to-config>qualificationStyle: Post | Pre | null
bannedModules: # can be null
Module.Name:
severity: Error | Warning
why: string with ban reason
importRules: # can be null
DataModuleName:
severity: Error | Warning
rules:
- qualification: Required | Forbidden | null
aliases:
# Either `exactly`, so alias can't be omitted
exactly:
- Module.Alias
- Alias
# or just list, so alias can be omitted
- Module.Alias
- Alias
# or null
importedNames:
# Either whitelist, so import should be
# accompanied with explicit import list
whitelist:
- pattern (:|>)
- type (+)
- foo
# or blacklist, so import should be
# accompanied with explicit hiding list with all these names
# or explicit import list shouldn't contain any of these names
blacklist:
- pattern (:|>)
- type (+)
- foo
# or nullqualificationStyle: Post
bannedModules:
# Forbids Data.Map at all
Data.Map:
severity: Error
why: Use 'Data.Map.Strict'
importRules:
# Either
# import Data.Text (Text)
# or
# import Data.Text qualified as Text
Data.Text:
severity: Warning
rules:
- qualification: Required
aliases:
exactly:
- Text
- qualification: Forbidden
importedNames:
whitelist:
- TextIt can be useful if you have a lot of projects with one style. So you haven't to copy paste config but just use style as library
- Create library package
- Add to deps
import-style-plugin - Create module
YourPlugin.hs(or something like that, it's unimportant) - Put there
module YourPlugin where import ImportStylePlugin.Derived qualified as Derived import ImportStylePlugin.Config as Cfg -- variable name `plugin` IS important -- Configure your style with Haskell types from `ImportStylePlugin.Config` plugin = Derived.plugin ImportsStyle { qualificationStyle = ... , bannedModules = ... , importRules = ... }
- Plug in
build-depends: ..., your-import-style-plugin, ... ghc-options: -fplugin YourPlugin
Since ghc-9.8 the plugin introduces custom warning x-import-style. So if you set -Werror but still want to style warnings be warnings use ghc option -Wwarn=x-import-style. You also can disable at all warnings with -Wno-x-import-style
