Prototype fix

src/ShellCheck/Analytics.hs

@@ -1336,7 +1336,10 @@ 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) =
-    style id 2006 "Use $(...) notation instead of legacy backticked `...`."
+    addComment $
+        makeCommentWithFix StyleC id 2006  "Use $(...) notation instead of legacy backticked `...`."
+            ((replaceStart 1 "$(") ++ (replaceEnd 1 ")"))
+    -- style id 2006 "Use $(...) notation instead of legacy backticked `...`."
 checkBackticks _ _ = return ()
 
 prop_checkIndirectExpansion1 = verify checkIndirectExpansion "${foo$n}"
@@ -1640,8 +1643,10 @@ 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
-                    "Double quote to prevent globbing and word splitting."
+                makeCommentWithFix InfoC (getId token) 2086
+                    "Double quote to prevent globbing and word splitting." (surroundWith "\"")
+                -- 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 +2543,9 @@ 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."
+                -- 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."
+                    (replaceEnd 0 " || exit")
     checkElement _ = return ()
     name t = fromMaybe "" $ getCommandName t
     isSafeDir t = case oversimplify t of
@@ -2695,7 +2702,7 @@ 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." (surroundWith "\"")
                 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

@@ -150,6 +150,19 @@ 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 in
+    comment {
+        tcFix = Just fix
+    }
+
 makeParameters spec =
     let params = Parameters {
         rootNode = root,

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!"

src/ShellCheck/Formatter/TTY.hs

@@ -129,8 +129,47 @@ outputForFile color sys comments = do
         putStrLn (color "source" line)
         mapM_ (\c -> putStrLn (color (severityText c) $ cuteIndent c)) x
         putStrLn ""
+        mapM_ (\c -> putStrLn "Did you mean:" >> putStrLn (fixedString c line)) x
       ) groups
 
+-- need to do something smart about sorting by end index
+fixedString :: PositionedComment -> String -> String
+fixedString comment line =
+    case (pcFix comment) of
+    Nothing -> ""
+    Just rs ->
+        apply_replacement rs line 0
+        where
+            apply_replacement [] s _ = s
+            apply_replacement ((Start n r):xs) s offset =
+                let start = (posColumn . pcStartPos) comment
+                    end = start + n
+                    z = do_replace start end s r
+                    len_r = (fromIntegral . length) r in
+                apply_replacement xs z (offset + (end - start) + len_r)
+            apply_replacement ((End n r):xs) s offset =
+                -- tricky math because column is 1 based
+                let end = (posColumn . pcEndPos) comment + 1
+                    start = end - n
+                    z = do_replace start end s r
+                    len_r = (fromIntegral . length) r in
+                apply_replacement xs z (offset + (end - start) + len_r)
+
+-- start and end comes from pos, which is 1 based
+-- do_replace 0 0 "1234" "A" -> "A1234" -- technically not valid
+-- do_replace 1 1 "1234" "A" -> "A1234"
+-- do_replace 1 2 "1234" "A" -> "A234"
+-- do_replace 3 3 "1234" "A" -> "12A34"
+-- do_replace 4 4 "1234" "A" -> "123A4"
+-- do_replace 5 5 "1234" "A" -> "1234A"
+do_replace 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

@@ -34,9 +34,9 @@ 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 +49,16 @@ module ShellCheck.Interface
     , emptyCheckSpec
     , newPositionedComment
     , newComment
+    , Fix
+    , Replacement(Start, End)
+    , surroundWith
+    , replaceStart
+    , replaceEnd
     ) where
 
 import ShellCheck.AST
 import Control.Monad.Identity
+import Data.Monoid
 import qualified Data.Map as Map
 
 
@@ -190,27 +196,50 @@ newComment = Comment {
     cMessage  = ""
 }
 
+-- only support single line for now
+data Replacement =
+      Start Integer String
+    | End Integer String
+    deriving (Show, Eq)
+
+type Fix = [Replacement]
+
+surroundWith s =
+    (replaceStart 0 s) ++ (replaceEnd 0 s)
+
+-- replace first n chars
+replaceStart n r =
+    [ Start n r ]
+
+-- replace last n chars
+replaceEnd n r =
+    [ End n r ]
+
 data PositionedComment = PositionedComment {
     pcStartPos :: Position,
     pcEndPos   :: Position,
-    pcComment  :: Comment
+    pcComment  :: Comment,
+    pcFix      :: Maybe Fix
 } deriving (Show, Eq)
 
 newPositionedComment :: PositionedComment
 newPositionedComment = PositionedComment {
     pcStartPos = newPosition,
     pcEndPos   = newPosition,
-    pcComment  = newComment
+    pcComment  = newComment,
+    pcFix      = Nothing
 }
 
 data TokenComment = TokenComment {
     tcId :: Id,
-    tcComment :: Comment
+    tcComment :: Comment,
+    tcFix :: Maybe Fix
 } deriving (Show, Eq)
 
 newTokenComment = TokenComment {
     tcId = Id 0,
-    tcComment = newComment
+    tcComment = newComment,
+    tcFix = Nothing
 }
 
 data ColorOption =