Improve Fix memory usage

.snapsquid.conf

@@ -1,14 +0,0 @@
-# In 2015, cabal-install had a http bug triggered when proxies didn't keep
-# the connection open. This version made it into Ubuntu Xenial as used by
-# Snapcraft. In June 2018, Snapcraft's proxy started triggering this bug.
-#
-#     https://bugs.launchpad.net/launchpad-buildd/+bug/1797809
-#
-# Workaround: add more proxy
-
-visible_hostname localhost
-http_port 8888
-cache_peer 10.10.10.1 parent 8222 0 no-query default
-cache_peer_domain localhost !.internal
-http_access allow all
-

CHANGELOG.md

@@ -1,26 +1,17 @@
-## v0.6.0 - 2018-12-02
+## ???
 ### Added
 - Command line option --severity/-S for filtering by minimum severity
 - Command line option --wiki-link-count/-W for showing wiki links
-- SC2152/SC2151: Warn about bad `exit` values like `1234` and `"foo"`
 - SC2236/SC2237: Suggest -n/-z instead of ! -z/-n
 - SC2238: Warn when redirecting to a known command name, e.g. ls > rm
 - SC2239: Warn if the shebang is not an absolute path, e.g. #!bin/sh
-- SC2240: Warn when passing additional arguments to dot (.) in sh/dash
 - SC1133: Better diagnostics when starting a line with |/||/&&
-
 ### Changed
 - Most warnings now have useful end positions
 - SC1117 about unknown double-quoted escape sequences has been retired
-
 ### Fixed
-- SC2021 no longer triggers for equivalence classes like `[=e=]`
+- SC2021 no longer triggers for equivalence classes like '[=e=]'
 - SC2221/SC2222 no longer mistriggers on fall-through case branches
-- SC2081 about glob matches in `[ .. ]` now also triggers for `!=`
-- SC2086 no longer warns about spaces in `$#`
-- SC2164 no longer suggests subshells for `cd ..; cmd; cd ..`
-- `read -a` is now correctly considered an array assignment
-- SC2039 no longer warns about LINENO now that it's POSIX
 
 ## v0.5.0 - 2018-05-31
 ### Added

Dockerfile

@@ -1,5 +1,5 @@
 # Build-only image
-FROM ubuntu:18.04 AS build
+FROM ubuntu:17.10 AS build
 USER root
 WORKDIR /opt/shellCheck
 

README.md

@@ -133,10 +133,6 @@ On OS X with homebrew:
 
     brew install shellcheck
 
-On OpenBSD:
-
-    pkg_add shellcheck
-
 On openSUSE
 
     zypper in ShellCheck
@@ -172,11 +168,6 @@ Alternatively, you can download pre-compiled binaries for the latest release her
 
 or see the [storage bucket listing](https://shellcheck.storage.googleapis.com/index.html) for checksums, older versions and the latest daily builds.
 
-Distro packages already come with a `man` page. If you are building from source, it can be installed with:
-
-    pandoc -s -t man shellcheck.1.md -o shellcheck.1
-    sudo mv shellcheck.1 /usr/share/man/man1
-
 ## Travis CI
 
 Travis CI has now integrated ShellCheck by default, so you don't need to manually install it.

Setup.hs

@@ -33,4 +33,4 @@ myPreSDist _ _ = do
   putStrLn $ "pandoc exited with " ++ show result
   return emptyHookedBuildInfo
   where
-    pandoc_cmd = "pandoc -s -f markdown-smart -t man shellcheck.1.md -o shellcheck.1"
+    pandoc_cmd = "pandoc -s -t man shellcheck.1.md -o shellcheck.1"

ShellCheck.cabal

@@ -1,5 +1,5 @@
 Name:             ShellCheck
-Version:          0.6.0
+Version:          0.5.0
 Synopsis:         Shell script analysis tool
 License:          GPL-3
 License-file:     LICENSE
@@ -28,8 +28,6 @@ Extra-Source-Files:
     shellcheck.1.md
     -- built with a cabal sdist hook
     shellcheck.1
-    -- convenience script for stripping tests
-    striptests
     -- tests
     test/shellcheck.hs
 
@@ -55,6 +53,7 @@ library
       base > 4.6.0.1 && < 5,
       bytestring,
       containers >= 0.5,
+      deepseq >= 1.4.0.0,
       directory,
       mtl >= 2.2.1,
       parsec,
@@ -91,6 +90,7 @@ executable shellcheck
       aeson,
       base >= 4 && < 5,
       bytestring,
+      deepseq >= 1.4.0.0,
       ShellCheck,
       containers,
       directory,
@@ -106,6 +106,7 @@ test-suite test-shellcheck
       aeson,
       base >= 4 && < 5,
       bytestring,
+      deepseq >= 1.4.0.0,
       ShellCheck,
       containers,
       directory,

snap/snapcraft.yaml

@@ -37,16 +37,9 @@ parts:
     source: ./
     build-packages:
       - cabal-install
-      - squid3
     build: |
-      # See comments in .snapsquid.conf
-      [ "$http_proxy" ] && {
-        squid3 -f .snapsquid.conf
-        export http_proxy="http://localhost:8888"
-        sleep 3
-      }
       cabal sandbox init
-      cabal update || cat /var/log/squid/*
+      cabal update
       cabal install -j
     install: |
       install -d $SNAPCRAFT_PART_INSTALL/usr/bin

src/ShellCheck/AST.hs

@@ -17,14 +17,17 @@
     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 DeriveGeneric, DeriveAnyClass #-}
 module ShellCheck.AST where
 
+import GHC.Generics (Generic)
 import Control.Monad.Identity
+import Control.DeepSeq
 import Text.Parsec
 import qualified ShellCheck.Regex as Re
 import Prelude hiding (id)
 
-newtype Id = Id Int deriving (Show, Eq, Ord)
+newtype Id = Id Int deriving (Show, Eq, Ord, Generic, NFData)
 
 data Quoted = Quoted | Unquoted deriving (Show, Eq)
 data Dashed = Dashed | Undashed deriving (Show, Eq)

src/ShellCheck/Analytics.hs

@@ -241,6 +241,39 @@ isCondition (child:parent:rest) =
             T_UntilExpression id c l -> take 1 . reverse $ c
             _ -> []
 
+-- helpers to build replacements
+replaceStart id params n r =
+    let tp = tokenPositions params
+        (start, _) = tp Map.! id
+        new_end = start {
+            posColumn = posColumn start + n
+        }
+    in
+    newReplacement {
+        repStartPos = start,
+        repEndPos = new_end,
+        repString = r
+    }
+replaceEnd id params n r =
+    -- because of the way we count columns 1-based
+    -- we have to offset end columns by 1
+    let tp = tokenPositions params
+        (_, end) = tp Map.! id
+        new_start = end {
+            posColumn = posColumn end - n + 1
+        }
+        new_end = end {
+            posColumn = posColumn end + 1
+        }
+    in
+    newReplacement {
+        repStartPos = new_start,
+        repEndPos = new_end,
+        repString = r
+    }
+surroundWidth id params s = fixWith [replaceStart id params 0 s, replaceEnd id params 0 s]
+fixWith fixes = newFix { fixReplacements = fixes }
+
 prop_checkEchoWc3 = verify checkEchoWc "n=$(echo $foo | wc -c)"
 checkEchoWc _ (T_Pipeline id _ [a, b]) =
     when (acmd == ["echo", "${VAR}"]) $
@@ -1197,12 +1230,11 @@ prop_checkComparisonAgainstGlob2 = verifyNot checkComparisonAgainstGlob "[[ $cow
 prop_checkComparisonAgainstGlob3 = verify checkComparisonAgainstGlob "[ $cow = *foo* ]"
 prop_checkComparisonAgainstGlob4 = verifyNot checkComparisonAgainstGlob "[ $cow = foo ]"
 prop_checkComparisonAgainstGlob5 = verify checkComparisonAgainstGlob "[[ $cow != $bar ]]"
-prop_checkComparisonAgainstGlob6 = verify checkComparisonAgainstGlob "[ $f != /* ]"
 checkComparisonAgainstGlob _ (TC_Binary _ DoubleBracket op _ (T_NormalWord id [T_DollarBraced _ _]))
     | op `elem` ["=", "==", "!="] =
         warn id 2053 $ "Quote the right-hand side of " ++ op ++ " in [[ ]] to prevent glob matching."
 checkComparisonAgainstGlob _ (TC_Binary _ SingleBracket op _ word)
-        | op `elem` ["=", "==", "!="] && isGlob word =
+        | (op == "=" || op == "==") && isGlob word =
     err (getId word) 2081 "[ .. ] can't match globs. Use [[ .. ]] or case statement."
 checkComparisonAgainstGlob _ _ = return ()
 
@@ -1335,8 +1367,10 @@ checkPS1Assignments _ _ = return ()
 prop_checkBackticks1 = verify checkBackticks "echo `foo`"
 prop_checkBackticks2 = verifyNot checkBackticks "echo $(foo)"
 prop_checkBackticks3 = verifyNot checkBackticks "echo `#inlined comment` foo"
-checkBackticks _ (T_Backticked id list) | not (null list) =
+checkBackticks params (T_Backticked id list) | not (null list) =
-    style id 2006 "Use $(...) notation instead of legacy backticked `...`."
+    addComment $
+        makeCommentWithFix StyleC id 2006  "Use $(...) notation instead of legacy backticked `...`."
+            (fixWith [replaceStart id params 1 "$(", replaceEnd id params 1 ")"])
 checkBackticks _ _ = return ()
 
 prop_checkIndirectExpansion1 = verify checkIndirectExpansion "${foo$n}"
@@ -1640,8 +1674,10 @@ checkSpacefulness params t =
                 makeComment InfoC (getId token) 2223
                     "This default assignment may cause DoS due to globbing. Quote it."
             else
-                makeComment InfoC (getId token) 2086
+                makeCommentWithFix InfoC (getId token) 2086
-                    "Double quote to prevent globbing and word splitting."
+                    "Double quote to prevent globbing and word splitting." (surroundWidth (getId token) params "\"")
+                -- makeComment InfoC (getId token) 2086
+                --     "Double quote to prevent globbing and word splitting."
 
     writeF _ _ name (DataString SourceExternal) = setSpaces name True >> return []
     writeF _ _ name (DataString SourceInteger) = setSpaces name False >> return []
@@ -2538,7 +2574,8 @@ checkUncheckedCdPushdPopd params root =
             && not (isSafeDir t)
             && not (name t `elem` ["pushd", "popd"] && ("n" `elem` map snd (getAllFlags t)))
             && not (isCondition $ getPath (parentMap params) t)) $
-                warn (getId t) 2164 "Use 'cd ... || exit' or 'cd ... || return' in case cd fails."
+                warnWithFix (getId t) 2164 "Use 'cd ... || exit' or 'cd ... || return' in case cd fails."
+                    (fixWith [replaceEnd (getId t) params 0 " || exit"])
     checkElement _ = return ()
     name t = fromMaybe "" $ getCommandName t
     isSafeDir t = case oversimplify t of
@@ -2695,7 +2732,7 @@ checkArrayAssignmentIndices params root =
                         T_Literal id str -> [(id,str)]
                         _ -> []
                     guard $ '=' `elem` str
-                    return $ warn id 2191 "The = here is literal. To assign by index, use ( [index]=value ) with no spaces. To keep as literal, quote it."
+                    return $ warnWithFix id 2191 "The = here is literal. To assign by index, use ( [index]=value ) with no spaces. To keep as literal, quote it." (surroundWidth id params "\"")
                 in
                     if null literalEquals && isAssociative
                     then warn (getId t) 2190 "Elements in associative arrays need index, e.g. array=( [index]=value ) ."

src/ShellCheck/AnalyzerLib.hs

@@ -20,26 +20,28 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TemplateHaskell  #-}
 module ShellCheck.AnalyzerLib where
-import           ShellCheck.AST
-import           ShellCheck.ASTLib
-import           ShellCheck.Data
-import           ShellCheck.Interface
-import           ShellCheck.Parser
-import           ShellCheck.Regex
 
-import           Control.Arrow          (first)
+import ShellCheck.AST
-import           Control.Monad.Identity
+import ShellCheck.ASTLib
-import           Control.Monad.RWS
+import ShellCheck.Data
-import           Control.Monad.State
+import ShellCheck.Interface
-import           Control.Monad.Writer
+import ShellCheck.Parser
-import           Data.Char
+import ShellCheck.Regex
-import           Data.List
-import qualified Data.Map               as Map
-import           Data.Maybe
-import           Data.Semigroup
 
-import           Test.QuickCheck.All    (forAllProperties)
+import Control.Arrow (first)
-import           Test.QuickCheck.Test   (maxSuccess, quickCheckWithResult, stdArgs)
+import Control.DeepSeq
+import Control.Monad.Identity
+import Control.Monad.RWS
+import Control.Monad.State
+import Control.Monad.Writer
+import Data.Char
+import Data.List
+import Data.Maybe
+import Data.Semigroup
+import qualified Data.Map as Map
+
+import Test.QuickCheck.All (forAllProperties)
+import Test.QuickCheck.Test (maxSuccess, quickCheckWithResult, stdArgs)
 
 type Analysis = AnalyzerM ()
 type AnalyzerM a = RWS Parameters [TokenComment] Cache a
@@ -81,7 +83,8 @@ data Parameters = Parameters {
     parentMap          :: Map.Map Id Token, -- A map from Id to parent Token
     shellType          :: Shell,            -- The shell type, such as Bash or Ksh
     shellTypeSpecified :: Bool,    -- True if shell type was forced via flags
-    rootNode           :: Token              -- The root node of the AST
+    rootNode           :: Token,              -- The root node of the AST
+    tokenPositions     :: Map.Map Id (Position, Position) -- map from token id to start and end position
     }
 
 -- TODO: Cache results of common AST ops here
@@ -142,7 +145,7 @@ makeComment severity id code note =
         }
     }
 
-addComment note = tell [note]
+addComment note = note `deepseq` tell [note]
 
 warn :: MonadWriter [TokenComment] m => Id -> Code -> String -> m ()
 warn  id code str = addComment $ makeComment WarningC id code str
@@ -150,6 +153,20 @@ err   id code str = addComment $ makeComment ErrorC id code str
 info  id code str = addComment $ makeComment InfoC id code str
 style id code str = addComment $ makeComment StyleC id code str
 
+warnWithFix id code str fix = addComment $
+    let comment = makeComment WarningC id code str in
+    comment {
+        tcFix = Just fix
+    }
+
+makeCommentWithFix :: Severity -> Id -> Code -> String -> Fix -> TokenComment
+makeCommentWithFix severity id code str fix =
+    let comment = makeComment severity id code str
+        withFix = comment {
+            tcFix = Just fix
+        }
+    in withFix `deepseq` withFix
+
 makeParameters spec =
     let params = Parameters {
         rootNode = root,
@@ -164,7 +181,8 @@ makeParameters spec =
 
         shellTypeSpecified = isJust $ asShellType spec,
         parentMap = getParentTree root,
-        variableFlow = getVariableFlow params root
+        variableFlow = getVariableFlow params root,
+        tokenPositions = asTokenPositions spec
     } in params
   where root = asScript spec
 

src/ShellCheck/Checker.hs

@@ -42,7 +42,8 @@ tokenToPosition startMap t = fromMaybe fail $ do
     return $ newPositionedComment {
         pcStartPos = fst span,
         pcEndPos = snd span,
-        pcComment = tcComment t
+        pcComment = tcComment t,
+        pcFix = tcFix t
     }
   where
     fail = error "Internal shellcheck error: id doesn't exist. Please report!"
@@ -63,11 +64,20 @@ checkScript sys spec = do
             psShellTypeOverride = csShellTypeOverride spec
         }
         let parseMessages = prComments result
+        let tokenPositions = prTokenPositions result
+        let analysisSpec root =
+                as {
+                    asScript = root,
+                    asShellType = csShellTypeOverride spec,
+                    asCheckSourced = csCheckSourced spec,
+                    asExecutionMode = Executed,
+                    asTokenPositions = tokenPositions
+                } where as = newAnalysisSpec root
         let analysisMessages =
                 fromMaybe [] $
                     (arComments . analyzeScript . analysisSpec)
                         <$> prRoot result
-        let translator = tokenToPosition (prTokenPositions result)
+        let translator = tokenToPosition tokenPositions
         return . nub . sortMessages . filter shouldInclude $
             (parseMessages ++ map translator analysisMessages)
 
@@ -90,13 +100,6 @@ checkScript sys spec = do
          cMessage comment)
     getPosition = pcStartPos
 
-    analysisSpec root =
-        as {
-            asScript = root,
-            asShellType = csShellTypeOverride spec,
-            asCheckSourced = csCheckSourced spec,
-            asExecutionMode = Executed
-         } where as = newAnalysisSpec root
 
 getErrors sys spec =
     sort . map getCode . crComments $

src/ShellCheck/Checks/Commands.hs

@@ -61,7 +61,6 @@ commandChecks = [
     ,checkGrepRe
     ,checkTrapQuotes
     ,checkReturn
-    ,checkExit
     ,checkFindExecWithSingleArgument
     ,checkUnusedEchoEscapes
     ,checkInjectableFindSh
@@ -93,7 +92,6 @@ commandChecks = [
     ,checkWhich
     ,checkSudoRedirect
     ,checkSudoArgs
-    ,checkSourceArgs
     ]
 
 buildCommandMap :: [CommandCheck] -> Map.Map CommandName (Token -> Analysis)
@@ -282,28 +280,15 @@ prop_checkReturn4 = verifyNot checkReturn "return $((a|b))"
 prop_checkReturn5 = verify checkReturn "return -1"
 prop_checkReturn6 = verify checkReturn "return 1000"
 prop_checkReturn7 = verify checkReturn "return 'hello world'"
-checkReturn = CommandCheck (Exactly "return") (returnOrExit
+checkReturn = CommandCheck (Exactly "return") (f . arguments)
-        (\c -> err c 2151 "Only one integer 0-255 can be returned. Use stdout for other data.")
-        (\c -> err c 2152 "Can only return 0-255. Other data should be written to stdout."))
-
-prop_checkExit1 = verifyNot checkExit "exit"
-prop_checkExit2 = verifyNot checkExit "exit 1"
-prop_checkExit3 = verifyNot checkExit "exit $var"
-prop_checkExit4 = verifyNot checkExit "exit $((a|b))"
-prop_checkExit5 = verify checkExit "exit -1"
-prop_checkExit6 = verify checkExit "exit 1000"
-prop_checkExit7 = verify checkExit "exit 'hello world'"
-checkExit = CommandCheck (Exactly "exit") (returnOrExit
-        (\c -> err c 2241 "The exit status can only be one integer 0-255. Use stdout for other data.")
-        (\c -> err c 2242 "Can only exit with status 0-255. Other data should be written to stdout/stderr."))
-
-returnOrExit multi invalid = (f . arguments)
   where
     f (first:second:_) =
-        multi (getId first)
+        err (getId second) 2151
+            "Only one integer 0-255 can be returned. Use stdout for other data."
     f [value] =
         when (isInvalid $ literal value) $
-            invalid (getId value)
+            err (getId value) 2152
+                "Can only return 0-255. Other data should be written to stdout."
     f _ = return ()
 
     isInvalid s = s == "" || any (not . isDigit) s || length s > 5
@@ -1023,16 +1008,5 @@ checkSudoArgs = CommandCheck (Basename "sudo") f
     -- This mess is why ShellCheck prefers not to know.
     parseOpts = getBsdOpts "vAknSbEHPa:g:h:p:u:c:T:r:"
 
-prop_checkSourceArgs1 = verify checkSourceArgs "#!/bin/sh\n. script arg"
-prop_checkSourceArgs2 = verifyNot checkSourceArgs "#!/bin/sh\n. script"
-prop_checkSourceArgs3 = verifyNot checkSourceArgs "#!/bin/bash\n. script arg"
-checkSourceArgs = CommandCheck (Exactly ".") f
-  where
-    f t = whenShell [Sh, Dash] $
-        case arguments t of
-            (file:arg1:_) -> warn (getId arg1) 2240 $
-                "The dot command does not support arguments in sh/dash. Set them as variables."
-            _ -> return ()
-
 return []
 runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Formatter/JSON.hs

@@ -39,7 +39,20 @@ format = do
         footer = finish ref
     }
 
-instance ToJSON (PositionedComment) where
+instance ToJSON Replacement where
+    toJSON replacement =
+        let start = repStartPos replacement
+            end = repEndPos replacement
+            str = repString replacement in
+        object [
+          "line" .= posLine start,
+          "endLine" .= posLine end,
+          "column" .= posColumn start,
+          "endColumn" .= posColumn end,
+          "replaceWith" .= str
+        ]
+
+instance ToJSON PositionedComment where
   toJSON comment =
     let start = pcStartPos comment
         end = pcEndPos comment
@@ -52,7 +65,8 @@ instance ToJSON (PositionedComment) where
       "endColumn" .= posColumn end,
       "level" .= severityText comment,
       "code" .= cCode c,
-      "message" .= cMessage c
+      "message" .= cMessage c,
+      "fix" .= pcFix comment
     ]
 
   toEncoding comment =
@@ -68,8 +82,14 @@ instance ToJSON (PositionedComment) where
       <> "level" .= severityText comment
       <> "code" .= cCode c
       <> "message" .= cMessage c
+      <> "fix" .= pcFix comment
     )
 
+instance ToJSON Fix where
+    toJSON fix = object [
+        "replacements" .= fixReplacements fix
+        ]
+
 outputError file msg = hPutStrLn stderr $ file ++ ": " ++ msg
 collectResult ref result _ =
     modifyIORef ref (\x -> crComments result ++ x)
@@ -77,4 +97,3 @@ collectResult ref result _ =
 finish ref = do
     list <- readIORef ref
     BL.putStrLn $ encode list
-

src/ShellCheck/Formatter/TTY.hs

@@ -25,6 +25,7 @@ import ShellCheck.Formatter.Format
 import Control.Monad
 import Data.IORef
 import Data.List
+import Data.Maybe
 import GHC.Exts
 import System.IO
 import System.Info
@@ -94,7 +95,7 @@ outputWiki errRef = do
   where
     showErr (_, code, msg) =
         putStrLn $ "  " ++ wikiLink ++ "SC" ++ show code ++ " -- " ++ shorten msg
-    limit = 36
+    limit = 40
     shorten msg =
         if length msg < limit
         then msg
@@ -118,8 +119,8 @@ outputForFile color sys comments = do
     let fileLines = lines contents
     let lineCount = fromIntegral $ length fileLines
     let groups = groupWith lineNo comments
-    mapM_ (\x -> do
+    mapM_ (\commentsForLine -> do
-        let lineNum = lineNo (head x)
+        let lineNum = lineNo (head commentsForLine)
         let line = if lineNum < 1 || lineNum > lineCount
                         then ""
                         else fileLines !! fromIntegral (lineNum - 1)
@@ -127,10 +128,62 @@ outputForFile color sys comments = do
         putStrLn $ color "message" $
            "In " ++ fileName ++" line " ++ show lineNum ++ ":"
         putStrLn (color "source" line)
-        mapM_ (\c -> putStrLn (color (severityText c) $ cuteIndent c)) x
+        mapM_ (\c -> putStrLn (color (severityText c) $ cuteIndent c)) commentsForLine
         putStrLn ""
+        -- FIXME: Enable when reasonably stable
+        -- showFixedString color comments lineNum line
       ) groups
 
+hasApplicableFix lineNum comment = fromMaybe False $ do
+    replacements <- fixReplacements <$> pcFix comment
+    guard $ all (\c -> onSameLine (repStartPos c) && onSameLine (repEndPos c)) replacements
+    return True
+  where
+    onSameLine pos = posLine pos == lineNum
+
+-- FIXME: Work correctly with multiple replacements
+showFixedString color comments lineNum line =
+    case filter (hasApplicableFix lineNum) comments of
+        (first:_) -> do
+            -- in the spirit of error prone
+            putStrLn $ color "message" "Did you mean: "
+            putStrLn $ fixedString first line
+            putStrLn ""
+        _ -> return ()
+
+-- need to do something smart about sorting by end index
+fixedString :: PositionedComment -> String -> String
+fixedString comment line =
+    case (pcFix comment) of
+    Nothing -> ""
+    Just rs ->
+        applyReplacement (fixReplacements rs) line 0
+        where
+            applyReplacement [] s _ = s
+            applyReplacement (rep:xs) s offset =
+                let replacementString = repString rep
+                    start = (posColumn . repStartPos) rep
+                    end = (posColumn . repEndPos) rep
+                    z = doReplace start end s replacementString
+                    len_r = (fromIntegral . length) replacementString in
+                applyReplacement xs z (offset + (end - start) + len_r)
+
+-- FIXME: Work correctly with tabs
+-- start and end comes from pos, which is 1 based
+-- doReplace 0 0 "1234" "A" -> "A1234" -- technically not valid
+-- doReplace 1 1 "1234" "A" -> "A1234"
+-- doReplace 1 2 "1234" "A" -> "A234"
+-- doReplace 3 3 "1234" "A" -> "12A34"
+-- doReplace 4 4 "1234" "A" -> "123A4"
+-- doReplace 5 5 "1234" "A" -> "1234A"
+doReplace start end o r =
+    let si = fromIntegral (start-1)
+        ei = fromIntegral (end-1)
+        (x, xs) = splitAt si o
+        (y, z) = splitAt (ei - si) xs
+    in
+    x ++ r ++ z
+
 cuteIndent :: PositionedComment -> String
 cuteIndent comment =
     replicate (fromIntegral $ colNo comment - 1) ' ' ++

src/ShellCheck/Interface.hs

@@ -17,6 +17,7 @@
     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 DeriveGeneric, DeriveAnyClass #-}
 module ShellCheck.Interface
     (
     SystemInterface(..)
@@ -24,7 +25,7 @@ module ShellCheck.Interface
     , CheckResult(crFilename, crComments)
     , ParseSpec(psFilename, psScript, psCheckSourced, psShellTypeOverride)
     , ParseResult(prComments, prTokenPositions, prRoot)
-    , AnalysisSpec(asScript, asShellType, asExecutionMode, asCheckSourced)
+    , AnalysisSpec(asScript, asShellType, asExecutionMode, asCheckSourced, asTokenPositions)
     , AnalysisResult(arComments)
     , FormatterOptions(foColorOption, foWikiLinkCount)
     , Shell(Ksh, Sh, Bash, Dash)
@@ -34,9 +35,9 @@ module ShellCheck.Interface
     , Severity(ErrorC, WarningC, InfoC, StyleC)
     , Position(posFile, posLine, posColumn)
     , Comment(cSeverity, cCode, cMessage)
-    , PositionedComment(pcStartPos , pcEndPos , pcComment)
+    , PositionedComment(pcStartPos , pcEndPos , pcComment, pcFix)
     , ColorOption(ColorAuto, ColorAlways, ColorNever)
-    , TokenComment(tcId, tcComment)
+    , TokenComment(tcId, tcComment, tcFix)
     , emptyCheckResult
     , newParseResult
     , newAnalysisSpec
@@ -49,10 +50,18 @@ module ShellCheck.Interface
     , emptyCheckSpec
     , newPositionedComment
     , newComment
+    , Fix(fixReplacements)
+    , newFix
+    , Replacement(repStartPos, repEndPos, repString)
+    , newReplacement
     ) where
 
 import ShellCheck.AST
+
+import Control.DeepSeq
 import Control.Monad.Identity
+import Data.Monoid
+import GHC.Generics (Generic)
 import qualified Data.Map as Map
 
 
@@ -126,14 +135,16 @@ data AnalysisSpec = AnalysisSpec {
     asScript :: Token,
     asShellType :: Maybe Shell,
     asExecutionMode :: ExecutionMode,
-    asCheckSourced :: Bool
+    asCheckSourced :: Bool,
+    asTokenPositions :: Map.Map Id (Position, Position)
 }
 
 newAnalysisSpec token = AnalysisSpec {
     asScript = token,
     asShellType = Nothing,
     asExecutionMode = Executed,
-    asCheckSourced = False
+    asCheckSourced = False,
+    asTokenPositions = Map.empty
 }
 
 newtype AnalysisResult = AnalysisResult {
@@ -163,12 +174,13 @@ data ExecutionMode = Executed | Sourced deriving (Show, Eq)
 type ErrorMessage = String
 type Code = Integer
 
-data Severity = ErrorC | WarningC | InfoC | StyleC deriving (Show, Eq, Ord)
+data Severity = ErrorC | WarningC | InfoC | StyleC
+    deriving (Show, Eq, Ord, Generic, NFData)
 data Position = Position {
     posFile :: String,    -- Filename
     posLine :: Integer,   -- 1 based source line
     posColumn :: Integer  -- 1 based source column, where tabs are 8
-} deriving (Show, Eq)
+} deriving (Show, Eq, Generic, NFData)
 
 newPosition :: Position
 newPosition = Position {
@@ -181,7 +193,7 @@ data Comment = Comment {
     cSeverity :: Severity,
     cCode     :: Code,
     cMessage  :: String
-} deriving (Show, Eq)
+} deriving (Show, Eq, Generic, NFData)
 
 newComment :: Comment
 newComment = Comment {
@@ -190,27 +202,52 @@ newComment = Comment {
     cMessage  = ""
 }
 
+-- only support single line for now
+data Replacement = Replacement {
+    repStartPos :: Position,
+    repEndPos :: Position,
+    repString :: String
+} deriving (Show, Eq, Generic, NFData)
+
+newReplacement = Replacement {
+    repStartPos = newPosition,
+    repEndPos = newPosition,
+    repString = ""
+}
+
+data Fix = Fix {
+    fixReplacements :: [Replacement]
+} deriving (Show, Eq, Generic, NFData)
+
+newFix = Fix {
+    fixReplacements = []
+}
+
 data PositionedComment = PositionedComment {
     pcStartPos :: Position,
     pcEndPos   :: Position,
-    pcComment  :: Comment
+    pcComment  :: Comment,
-} deriving (Show, Eq)
+    pcFix      :: Maybe Fix
+} deriving (Show, Eq, Generic, NFData)
 
 newPositionedComment :: PositionedComment
 newPositionedComment = PositionedComment {
     pcStartPos = newPosition,
     pcEndPos   = newPosition,
-    pcComment  = newComment
+    pcComment  = newComment,
+    pcFix      = Nothing
 }
 
 data TokenComment = TokenComment {
     tcId :: Id,
-    tcComment :: Comment
+    tcComment :: Comment,
-} deriving (Show, Eq)
+    tcFix :: Maybe Fix
+} deriving (Show, Eq, Generic, NFData)
 
 newTokenComment = TokenComment {
     tcId = Id 0,
-    tcComment = newComment
+    tcComment = newComment,
+    tcFix = Nothing
 }
 
 data ColorOption =

src/ShellCheck/Parser.hs

@@ -1916,9 +1916,8 @@ readNewlineList =
   where
     checkBadBreak = optional $ do
                 pos <- getPosition
-                try $ lookAhead (oneOf "|&") --  See if the next thing could be |, || or &&
+                try $ lookAhead (oneOf "|&") -- |, || or &&
-                parseProblemAt pos ErrorC 1133
+                parseProblemAt pos ErrorC 1133 "Unexpected start of line. If breaking lines, |/||/&& should be at the end of the previous one."
-                    "Unexpected start of line. If breaking lines, |/||/&& should be at the end of the previous one."
 readLineBreak = optional readNewlineList
 
 prop_readSeparator1 = isWarning readScript "a &; b"

test/distrotest

@@ -16,14 +16,10 @@ and is still highly experimental.
 
 Make sure you're plugged in and have screen/tmux in place,
 then re-run with $0 --run to continue.
-
-Also note that 'dist' will be deleted.
 EOF
 exit 0
 }
 
-echo "Deleting 'dist'..."
-rm -rf dist
 
 log=$(mktemp) || die "Can't create temp file"
 date >> "$log" || die "Can't write to log"
@@ -67,8 +63,7 @@ opensuse:latest       zypper install -y cabal-install ghc
 ubuntu:18.04          apt-get update && apt-get install -y cabal-install
 ubuntu:17.10          apt-get update && apt-get install -y cabal-install
 
-# Misc Haskell including current and latest Stack build
+# Misc
-ubuntu:18.10          set -e; apt-get update && apt-get install -y curl && curl -sSL https://get.haskellstack.org/ | sh -s - -f && cd /mnt && exec test/stacktest
 haskell:latest        true
 
 # Known to currently fail

test/stacktest

@@ -1,27 +0,0 @@
-#!/bin/bash
-# This script builds ShellCheck through `stack` using
-# various resolvers. It's run via distrotest.
-
-resolvers=(
-  nightly-"$(date -d "3 days ago" +"%Y-%m-%d")"
-)
-
-die() { echo "$*" >&2; exit 1; }
-
-[ -e "ShellCheck.cabal" ] ||
-  die "ShellCheck.cabal not in current dir"
-[ -e "stack.yaml" ] ||
-  die "stack.yaml not in current dir"
-command -v stack ||
-  die "stack is missing"
-
-stack setup        || die "Failed to setup with default resolver"
-stack build --test || die "Failed to build/test with default resolver"
-
-for resolver in "${resolvers[@]}"
-do
-  stack --resolver="$resolver" setup        || die "Failed to setup $resolver"
-  stack --resolver="$resolver" build --test || die "Failed build/test with $resolver!"
-done
-
-echo "Success"