Add EditorConfig support for shellcheck directives

Co-authored-by: Freed-Wu <32936898+Freed-Wu@users.noreply.github.com>

Author: Copilot

ShellCheck.cabal

@@ -84,6 +84,7 @@ library
       ShellCheck.Checks.Custom
       ShellCheck.Checks.ShellSupport
       ShellCheck.Data
+      ShellCheck.EditorConfig
       ShellCheck.Fixer
       ShellCheck.Formatter.Format
       ShellCheck.Formatter.CheckStyle

shellcheck.1.md

@@ -334,6 +334,31 @@ Use `shellcheckrc` without the dot instead.
 Note for Docker users: ShellCheck will only be able to look for files that
 are mounted in the container, so `~/.shellcheckrc` will not be read.
 
+# EDITORCONFIG
+
+Unless `--norc` is used, ShellCheck will also look for a file `.editorconfig`
+in the script's directory and each parent directory. Any section whose glob
+pattern matches the checked file will have its `shellcheck.*` keys read as
+directives, with the `shellcheck.` prefix stripped. This uses the same
+`key=value` syntax as `.shellcheckrc`.
+
+For example:
+
+    [*.{ebuild,eclass}]
+    shellcheck.shell=bash
+    shellcheck.disable=SC2034
+
+    [{PKGBUILD,APKBUILD}]
+    shellcheck.shell=bash
+    shellcheck.disable=SC2034
+
+If no matching directives are found in any `.editorconfig` in the parent
+directories, ShellCheck will look in the global default
+`$XDG_CONFIG_HOME/editorconfig.ini` (usually `~/.config/editorconfig.ini`).
+
+Directives from `.shellcheckrc`/`shellcheckrc` and from `.editorconfig` are
+both applied, with `.shellcheckrc` taking precedence in case of conflicts.
+
 
 # ENVIRONMENT VARIABLES
 

shellcheck.hs

@@ -20,6 +20,7 @@
 import qualified ShellCheck.Analyzer
 import           ShellCheck.Checker
 import           ShellCheck.Data
+import           ShellCheck.EditorConfig
 import           ShellCheck.Interface
 import           ShellCheck.Regex
 
@@ -514,8 +515,22 @@ ioInterface options files = do
         fallback path _ = return path
 
 
-    -- Returns the name and contents of .shellcheckrc for the given file
-    getConfig cache filename =
+    -- Returns the name and contents of .shellcheckrc for the given file,
+    -- merged with any shellcheck.* directives found in applicable
+    -- EditorConfig files.
+    getConfig cache filename = do
+        rcResult <- getRcConfig cache filename
+        ecResult <- getEditorConfig filename
+        return $ mergeConfigs filename rcResult ecResult
+
+    mergeConfigs filename rcResult ecResult =
+        case (rcResult, ecResult) of
+            (Nothing, Nothing) -> Nothing
+            (Just (_, rc), Nothing) -> Just (filename, rc)
+            (Nothing, Just ec) -> Just (filename, ec)
+            (Just (_, rc), Just ec) -> Just (filename, rc ++ "\n" ++ ec)
+
+    getRcConfig cache filename =
         case rcfile options of
             Just file -> do
                 -- We have a specified rcfile. Ignore normal rcfile resolution.
@@ -541,6 +556,47 @@ ioInterface options files = do
                     writeIORef cache (dir, result)
                     return result
 
+    -- Look for .editorconfig files in the target file's directory and
+    -- all its parents (as per the EditorConfig spec), plus the global
+    -- ${XDG_CONFIG_HOME}/editorconfig.ini default. shellcheck.* keys in
+    -- matching sections are turned into directives.
+    getEditorConfig filename = do
+        path <- normalize filename
+        dirConfigs <- collectDirConfigs (takeDirectory path)
+        globalConfig <- readGlobalEditorConfig
+        let directives = concatMap (directivesFor path) (dirConfigs ++ globalConfig)
+        return $ if null directives then Nothing else Just (concat directives)
+      where
+        directivesFor path (file, contents) =
+            let relative = makeRelativeTo (takeDirectory file) path
+                result = parseEditorConfig contents relative
+            in [result | not (null result)]
+
+        makeRelativeTo dir path =
+            case stripPrefix (addTrailingSlash dir) path of
+                Just rest -> rest
+                Nothing -> takeFileName path
+
+        addTrailingSlash dir
+            | null dir = dir
+            | last dir == '/' = dir
+            | otherwise = dir ++ "/"
+
+        collectDirConfigs dir = do
+            let next = takeDirectory dir
+            rest <- if next /= dir
+                    then collectDirConfigs next
+                    else return []
+            current <- readConfig (dir </> ".editorconfig")
+            return $ maybeToList current ++ rest
+
+        readGlobalEditorConfig = do
+            path <- (getXdgDirectory XdgConfig "editorconfig.ini")
+                        `catch` ((const $ return "") :: IOException -> IO FilePath)
+            if null path
+              then return []
+              else maybeToList <$> readConfig path
+
     findConfig paths =
         case paths of
             (file:rest) -> do

src/ShellCheck/EditorConfig.hs

@@ -0,0 +1,145 @@
+{-
+    Copyright 2012-2024 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+
+{-# LANGUAGE TemplateHaskell #-}
+-- Minimal support for reading shellcheck directives from EditorConfig
+-- style files (https://editorconfig.org/). Only the `shellcheck.*` keys
+-- of sections whose glob matches the file being checked are extracted,
+-- and turned into the same "key=value" directive syntax that is used in
+-- .shellcheckrc files.
+module ShellCheck.EditorConfig (parseEditorConfig, globToRegexString, runTests) where
+
+import Data.Char
+import Data.List
+import Data.Maybe
+
+import ShellCheck.Regex
+
+import Test.QuickCheck
+
+-- Given the contents of an EditorConfig style file and the name of the
+-- file being checked, return the shellcheck directives (as a
+-- "key=value\n" delimited blob, suitable for feeding into the same
+-- parser as .shellcheckrc) found in matching sections.
+parseEditorConfig :: String -> FilePath -> String
+parseEditorConfig contents name =
+    unlines . concatMap sectionDirectives $ sections
+  where
+    ls = lines contents
+    sections = splitSections ls
+
+    splitSections [] = []
+    splitSections (l:rest) =
+        case parseHeader l of
+            Just pat ->
+                let (body, rest') = break (isJust . parseHeader) rest
+                in (pat, body) : splitSections rest'
+            Nothing -> splitSections rest
+
+    parseHeader l =
+        let t = trim (stripComment l)
+        in case t of
+            ('[':cs@(_:_)) | last cs == ']' -> Just (init cs)
+            _ -> Nothing
+
+    sectionDirectives (pat, body) =
+        if matchesGlob pat name
+        then mapMaybe toDirective body
+        else []
+
+    toDirective l =
+        let t = trim (stripComment l)
+        in case break (== '=') t of
+            (key, '=':value) ->
+                let key' = trim key
+                    value' = trim value
+                in if "shellcheck." `isPrefixOf` key'
+                    then Just (drop (length "shellcheck.") key' ++ "=" ++ value')
+                    else Nothing
+            _ -> Nothing
+
+    stripComment = takeWhile (\c -> c /= '#' && c /= ';')
+
+trim :: String -> String
+trim = dropWhileEnd isSpace . dropWhile isSpace
+
+-- Does the (basename of the) file match the given EditorConfig glob?
+matchesGlob :: String -> FilePath -> Bool
+matchesGlob pattern name =
+    name `matches` mkRegex (globToRegexString pattern)
+
+-- Translate an EditorConfig glob pattern into an anchored regex string.
+globToRegexString :: String -> String
+globToRegexString pattern = "^" ++ go pattern ++ "$"
+  where
+    go [] = ""
+    go ('*':'*':rest) = ".*" ++ go rest
+    go ('*':rest) = "[^/]*" ++ go rest
+    go ('?':rest) = "[^/]" ++ go rest
+    go ('[':rest) =
+        let (cls, rest') = break (== ']') rest
+        in case rest' of
+            (']':rest'') -> "[" ++ translateClass cls ++ "]" ++ go rest''
+            _ -> "\\[" ++ go rest
+    go ('{':rest) =
+        let (body, rest') = break (== '}') rest
+        in case rest' of
+            ('}':rest'') ->
+                "(" ++ intercalate "|" (map go (splitCommas body)) ++ ")" ++ go rest''
+            _ -> "\\{" ++ go rest
+    go (c:rest)
+        | c `elem` regexSpecials = ['\\', c] ++ go rest
+        | otherwise = c : go rest
+
+    regexSpecials = ".\\+()^$|"
+
+    translateClass ('!':cs) = '^' : escapeClass cs
+    translateClass cs = escapeClass cs
+    escapeClass = concatMap (\c -> if c == '\\' then "\\\\" else [c])
+
+    splitCommas s =
+        case break (== ',') s of
+            (before, ',':after) -> before : splitCommas after
+            (before, "") -> [before]
+            (before, after) -> [before ++ after]
+
+prop_globStar = matchesGlob "*.ebuild" "foo.ebuild"
+prop_globBraceExt = matchesGlob "*.{ebuild,eclass}" "foo.eclass"
+prop_globBraceExt2 = matchesGlob "*.{ebuild,eclass}" "foo.ebuild"
+prop_globBraceName = matchesGlob "{PKGBUILD,APKBUILD}" "PKGBUILD"
+prop_globBraceName2 = matchesGlob "{PKGBUILD,APKBUILD}" "APKBUILD"
+prop_globNoMatch = not $ matchesGlob "*.ebuild" "foo.txt"
+prop_globQuestion = matchesGlob "foo?.sh" "food.sh"
+prop_globClass = matchesGlob "foo[0-9].sh" "foo1.sh"
+prop_globClassNeg = not $ matchesGlob "foo[!0-9].sh" "foo1.sh"
+
+prop_parseEditorConfig1 =
+    parseEditorConfig "[*.{ebuild,eclass}]\nshellcheck.shell=bash\nshellcheck.disable=SC2034\n" "foo.ebuild"
+        == "shell=bash\ndisable=SC2034\n"
+prop_parseEditorConfig2 =
+    parseEditorConfig "[*.{ebuild,eclass}]\nshellcheck.shell=bash\n" "foo.txt" == ""
+prop_parseEditorConfig3 =
+    parseEditorConfig "[{PKGBUILD,APKBUILD}]\nshellcheck.disable=SC2034\n" "PKGBUILD" == "disable=SC2034\n"
+prop_parseEditorConfig4 =
+    parseEditorConfig "root = true\n[*.sh]\nindent_style = space\nshellcheck.shell=bash\n" "foo.sh"
+        == "shell=bash\n"
+
+return []
+runTests = $quickCheckAll

test/shellcheck.hs

@@ -12,6 +12,7 @@ import qualified ShellCheck.Checks.Commands
 import qualified ShellCheck.Checks.ControlFlow
 import qualified ShellCheck.Checks.Custom
 import qualified ShellCheck.Checks.ShellSupport
+import qualified ShellCheck.EditorConfig
 import qualified ShellCheck.Fixer
 import qualified ShellCheck.Formatter.Diff
 import qualified ShellCheck.Parser
@@ -35,6 +36,7 @@ main = do
       , ("Checks.ControlFlow" , ShellCheck.Checks.ControlFlow.runTests)
       , ("Checks.Custom"      , ShellCheck.Checks.Custom.runTests)
       , ("Checks.ShellSupport", ShellCheck.Checks.ShellSupport.runTests)
+      , ("EditorConfig"       , ShellCheck.EditorConfig.runTests)
       , ("Fixer"              , ShellCheck.Fixer.runTests)
       , ("Formatter.Diff"     , ShellCheck.Formatter.Diff.runTests)
       , ("Parser"             , ShellCheck.Parser.runTests)