Fix #918 - Save prettier details for Haskell linters

2 files changed, 56 insertions, 12 deletions

diff --git a/autoload/ale/handlers/haskell.vim b/autoload/ale/handlers/haskell.vim
index 09606692..8a0d0013 100644
--- a/autoload/ale/handlers/haskell.vim
+++ b/autoload/ale/handlers/haskell.vim
@@ -24,20 +24,25 @@ function! ale#handlers#haskell#HandleGHCFormat(buffer, lines) abort
 
     let l:corrected_lines = []
 
+    " Group the lines into smaller lists.
     for l:line in a:lines
         if len(matchlist(l:line, l:pattern)) > 0
-            call add(l:corrected_lines, l:line)
+            call add(l:corrected_lines, [l:line])
         elseif l:line is# ''
-            call add(l:corrected_lines, l:line)
-        else
-            if len(l:corrected_lines) > 0
-                let l:line = substitute(l:line, '\v^\s+', ' ', '')
-                let l:corrected_lines[-1] .= l:line
-            endif
+            call add(l:corrected_lines, [l:line])
+        elseif len(l:corrected_lines) > 0
+            call add(l:corrected_lines[-1], l:line)
         endif
     endfor
 
-    for l:line in l:corrected_lines
+    for l:line_list in l:corrected_lines
+        " Join the smaller lists into one large line to parse.
+        let l:line = l:line_list[0]
+
+        for l:extra_line in l:line_list[1:]
+            let l:line .= substitute(l:extra_line, '\v^\s+', ' ', '')
+        endfor
+
         let l:match = matchlist(l:line, l:pattern)
 
         if len(l:match) == 0
@@ -67,12 +72,19 @@ function! ale#handlers#haskell#HandleGHCFormat(buffer, lines) abort
         " Replace temporary filenames in problem messages with the basename
         let l:text = substitute(l:text, l:temp_filename_regex, l:basename, 'g')
 
-        call add(l:output, {
+        let l:item = {
         \   'lnum': l:match[2] + 0,
         \   'col': l:match[3] + 0,
         \   'text': l:text,
         \   'type': l:type,
-        \})
+        \}
+
+        " Include extra lines as details if they are there.
+        if len(l:line_list) > 1
+            let l:item.detail = join(l:line_list[1:], "\n")
+        endif
+
+        call add(l:output, l:item)
     endfor
 
     return l:output
diff --git a/test/handler/test_ghc_handler.vader b/test/handler/test_ghc_handler.vader
index b47cdf67..2a26f863 100644
--- a/test/handler/test_ghc_handler.vader
+++ b/test/handler/test_ghc_handler.vader
@@ -8,6 +8,10 @@ Execute(The ghc handler should handle hdevtools output):
   \     'type': 'W',
   \     'col': 62,
   \     'text': '• Couldnt match type ‘a -> T.Text’ with ‘T.Text’ Expected type: [T.Text]',
+  \     'detail': join([
+  \       '• Couldnt match type ‘a -> T.Text’ with ‘T.Text’',
+  \       '  Expected type: [T.Text]',
+  \     ], "\n"),
   \   },
   \ ],
   \ ale#handlers#haskell#HandleGHCFormat(bufnr(''), [
@@ -26,12 +30,20 @@ Execute(The ghc handler should handle ghc 8 output):
   \     'type': 'E',
   \     'col': 1,
   \     'text': 'Failed to load interface for ‘GitHub.Data’ Use -v to see a list of the files searched for.',
+  \     'detail': join([
+  \       '    Failed to load interface for ‘GitHub.Data’',
+  \       '    Use -v to see a list of the files searched for.',
+  \     ], "\n"),
   \   },
   \   {
   \     'lnum': 7,
   \     'type': 'W',
   \     'col': 1,
   \     'text': 'Failed to load interface for ‘GitHub.Endpoints.PullRequests’ Use -v to see a list of the files searched for.',
+  \     'detail': join([
+  \       '    Failed to load interface for ‘GitHub.Endpoints.PullRequests’',
+  \       '    Use -v to see a list of the files searched for.',
+  \     ], "\n"),
   \   },
   \ ],
   \ ale#handlers#haskell#HandleGHCFormat(bufnr(''), [
@@ -55,24 +67,36 @@ Execute(The ghc handler should handle ghc 7 output):
   \     'type': 'E',
   \     'col': 1,
   \     'text': 'parse error (possibly incorrect indentation or mismatched brackets)',
+  \     'detail': join([
+  \       '    parse error (possibly incorrect indentation or mismatched brackets)',
+  \     ], "\n"),
   \   },
   \   {
   \     'lnum': 84,
   \     'col': 1,
   \     'type': 'W',
-  \     'text': 'Top-level binding with no type signature:^@  myLayout :: Choose Tall (Choose (Mirror Tall) Full) a',
+  \     'text': 'Top-level binding with no type signature: myLayout :: Choose Tall (Choose (Mirror Tall) Full) a',
+  \     'detail': join([
+  \       '    Top-level binding with no type signature:',
+  \       '    myLayout :: Choose Tall (Choose (Mirror Tall) Full) a',
+  \     ], "\n"),
   \   },
   \   {
   \     'lnum': 94,
   \     'col': 5,
   \     'type': 'E',
   \     'text': 'Some other error',
+  \     'detail': join([
+  \       '  Some other error',
+  \     ], "\n"),
   \   },
   \ ],
   \ ale#handlers#haskell#HandleGHCFormat(bufnr(''), [
   \ ale#path#Winify('src/Main.hs') . ':168:1:',
   \ '    parse error (possibly incorrect indentation or mismatched brackets)',
-  \ ale#path#Winify('src/Main.hs') . ':84:1:Warning: Top-level binding with no type signature:^@  myLayout :: Choose Tall (Choose (Mirror Tall) Full) a',
+  \ ale#path#Winify('src/Main.hs') . ':84:1:Warning:',
+  \ '    Top-level binding with no type signature:',
+  \ '    myLayout :: Choose Tall (Choose (Mirror Tall) Full) a',
   \ ale#path#Winify('src/Main.hs') . ':94:5:Error:',
   \ '  Some other error',
   \ ])
@@ -87,6 +111,14 @@ Execute(The ghc handler should handle stack 1.5.1 output):
   \     'col': 14,
   \     'type': 'E',
   \     'text': '• Expecting one fewer arguments to ‘Exp’ Expected kind ‘k0 -> *’, but ‘Exp’ has kind ‘*’ • In the type ‘Exp a’ | 160 | pattern F :: Exp a |              ^^^^^',
+  \     'detail': join([
+  \       '        • Expecting one fewer arguments to ‘Exp’',
+  \       '          Expected kind ‘k0 -> *’, but ‘Exp’ has kind ‘*’',
+  \       '        • In the type ‘Exp a’',
+  \       '        |',
+  \       '    160 | pattern F :: Exp a',
+  \       '        |              ^^^^^',
+  \     ], "\n"),
   \   },
   \ ],
   \ ale#handlers#haskell#HandleGHCFormat(bufnr(''), [