Update parsing to strip whitespace from table cells (#1074)

* Update parsing to strip leading & trailing whitespace from table cells

* Update fixture data to disallow whitespaces at both ends in table cells

* Add test case for whitespaces stripped from both ends of table cells

* Update table reference test data for html tests

9 files changed, 102 insertions, 98 deletions

diff --git a/haddock-library/fixtures/examples/table-cell-strip-whitespaces.input b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.input
new file mode 100644
index 00000000..f5e3756d
--- /dev/null
+++ b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.input
@@ -0,0 +1,5 @@
++------+--------------+-------------------------------------------------+
+| C1   |     C2       |         C3                                      |
++======+==============+=================================================+
+| row  | 'test'       | 'test table cell with  .. whitepspace '         |
++------+--------------+-------------------------------------------------+
diff --git a/haddock-library/fixtures/examples/table-cell-strip-whitespaces.parsed b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.parsed
new file mode 100644
index 00000000..19002369
--- /dev/null
+++ b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.parsed
@@ -0,0 +1,29 @@
+DocTable
+  Table
+    {tableBodyRows = [TableRow
+                        [TableCell
+                           {tableCellColspan = 1,
+                            tableCellContents = DocString "row",
+                            tableCellRowspan = 1},
+                         TableCell
+                           {tableCellColspan = 1,
+                            tableCellContents = DocIdentifier "test",
+                            tableCellRowspan = 1},
+                         TableCell
+                           {tableCellColspan = 1,
+                            tableCellContents = DocString
+                                                  "'test table cell with  .. whitepspace '",
+                            tableCellRowspan = 1}]],
+     tableHeaderRows = [TableRow
+                          [TableCell
+                             {tableCellColspan = 1,
+                              tableCellContents = DocString "C1",
+                              tableCellRowspan = 1},
+                           TableCell
+                             {tableCellColspan = 1,
+                              tableCellContents = DocString "C2",
+                              tableCellRowspan = 1},
+                           TableCell
+                             {tableCellColspan = 1,
+                              tableCellContents = DocString "C3",
+                              tableCellRowspan = 1}]]}
diff --git a/haddock-library/fixtures/examples/table-simple.parsed b/haddock-library/fixtures/examples/table-simple.parsed
index b5e62453..d027c75d 100644
--- a/haddock-library/fixtures/examples/table-simple.parsed
+++ b/haddock-library/fixtures/examples/table-simple.parsed
@@ -3,50 +3,40 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " 200  ",
+                            tableCellContents = DocString "200",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocAppend
-                                                  (DocString "   ")
-                                                  (DocAppend
-                                                     (DocMonospaced (DocString "OK"))
-                                                     (DocString "       ")),
+                            tableCellContents = DocMonospaced (DocString "OK"),
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString
-                                                  " operation successful                     ",
+                            tableCellContents = DocString "operation successful",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " 204  ",
+                            tableCellContents = DocString "204",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocAppend
-                                                  (DocString " ")
-                                                  (DocAppend
-                                                     (DocMonospaced (DocString "No Content"))
-                                                     (DocString " ")),
+                            tableCellContents = DocMonospaced (DocString "No Content"),
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
                             tableCellContents = DocString
-                                                  " operation successful, no body returned   ",
+                                                  "operation successful, no body returned",
                             tableCellRowspan = 1}]],
      tableHeaderRows = [TableRow
                           [TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " code ",
+                              tableCellContents = DocString "code",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " message      ",
+                              tableCellContents = DocString "message",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    " description                              ",
+                              tableCellContents = DocString "description",
                               tableCellRowspan = 1}]]}
diff --git a/haddock-library/fixtures/examples/table1.parsed b/haddock-library/fixtures/examples/table1.parsed
index 2fa58fd8..8b8908f4 100644
--- a/haddock-library/fixtures/examples/table1.parsed
+++ b/haddock-library/fixtures/examples/table1.parsed
@@ -3,79 +3,66 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 1, column 1   ",
+                            tableCellContents = DocString "body row 1, column 1",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 2   ",
+                            tableCellContents = DocString "column 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 3 ",
+                            tableCellContents = DocString "column 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 4 ",
+                            tableCellContents = DocString "column 4",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 2             ",
+                            tableCellContents = DocString "body row 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 3,
-                            tableCellContents = DocString " Cells may span columns.          ",
+                            tableCellContents = DocString "Cells may span columns.",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 3             ",
+                            tableCellContents = DocString "body row 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
                             tableCellContents = DocString
-                                                  (concat
-                                                     [" Cells may  \n",
-                                                      " span rows. \n",
-                                                      "            "]),
+                                                  (concat ["Cells may\n", "span rows.\n"]),
                             tableCellRowspan = 2},
                          TableCell
                            {tableCellColspan = 2,
-                            tableCellContents = DocAppend
-                                                  (DocString " ")
-                                                  (DocAppend
-                                                     (DocMathDisplay
-                                                        (concat
-                                                           ["                  \n",
-                                                            " f(n) = \\sum_{i=1}   \n",
-                                                            " "]))
-                                                     (DocString "                  ")),
+                            tableCellContents = DocMathDisplay
+                                                  (concat ["\n", "f(n) = \\sum_{i=1}\n"]),
                             tableCellRowspan = 2}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 4             ",
+                            tableCellContents = DocString "body row 4",
                             tableCellRowspan = 1}]],
      tableHeaderRows = [TableRow
                           [TableCell
                              {tableCellColspan = 1,
                               tableCellContents = DocString
                                                     (concat
-                                                       [" Header row, column 1   \n",
-                                                        " (header rows optional) "]),
+                                                       ["Header row, column 1\n",
+                                                        "(header rows optional)"]),
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    (concat [" Header 2   \n", "            "]),
+                              tableCellContents = DocString "Header 2\n",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    (concat [" Header 3 \n", "          "]),
+                              tableCellContents = DocString "Header 3\n",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    (concat [" Header 4 \n", "          "]),
+                              tableCellContents = DocString "Header 4\n",
                               tableCellRowspan = 1}]]}
diff --git a/haddock-library/fixtures/examples/table2.parsed b/haddock-library/fixtures/examples/table2.parsed
index e3dbf0b4..44cc813b 100644
--- a/haddock-library/fixtures/examples/table2.parsed
+++ b/haddock-library/fixtures/examples/table2.parsed
@@ -3,44 +3,44 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 1, col 1 ",
+                            tableCellContents = DocString "row 1, col 1",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 2 ",
+                            tableCellContents = DocString "column 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 3  ",
+                            tableCellContents = DocString "column 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 4  ",
+                            tableCellContents = DocString "column 4",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 2        ",
+                            tableCellContents = DocString "row 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 3,
-                            tableCellContents = DocString "                                  ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 3        ",
+                            tableCellContents = DocString "row 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "          ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}]],
      tableHeaderRows = []}
diff --git a/haddock-library/fixtures/examples/table3.parsed b/haddock-library/fixtures/examples/table3.parsed
index cabff9cb..c978b50f 100644
--- a/haddock-library/fixtures/examples/table3.parsed
+++ b/haddock-library/fixtures/examples/table3.parsed
@@ -3,48 +3,48 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 1, col 1 ",
+                            tableCellContents = DocString "row 1, col 1",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 2 ",
+                            tableCellContents = DocString "column 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 3  ",
+                            tableCellContents = DocString "column 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 4  ",
+                            tableCellContents = DocString "column 4",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 2        ",
+                            tableCellContents = DocString "row 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 2,
-                            tableCellContents = DocString " Use the command ``ls ",
+                            tableCellContents = DocString "Use the command ``ls",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " more``.   ",
+                            tableCellContents = DocString "more``.",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 3        ",
+                            tableCellContents = DocString "row 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "          ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}]],
      tableHeaderRows = []}
diff --git a/haddock-library/fixtures/examples/table4.parsed b/haddock-library/fixtures/examples/table4.parsed
index cfdd6f0f..c4dabb0d 100644
--- a/haddock-library/fixtures/examples/table4.parsed
+++ b/haddock-library/fixtures/examples/table4.parsed
@@ -8,10 +8,10 @@ DocAppend
                                  {tableCellColspan = 1,
                                   tableCellContents = DocString
                                                         (concat
-                                                           ["   outer     \n",
-                                                            "             \n",
-                                                            "-------+     \n",
-                                                            " inner |     "]),
+                                                           ["outer\n",
+                                                            "\n",
+                                                            "-------+\n",
+                                                            "inner |"]),
                                   tableCellRowspan = 1}]],
            tableHeaderRows = []})
      (DocAppend
@@ -21,6 +21,6 @@ DocAppend
              {tableBodyRows = [TableRow
                                  [TableCell
                                     {tableCellColspan = 1,
-                                     tableCellContents = DocString " inner ",
+                                     tableCellContents = DocString "inner",
                                      tableCellRowspan = 1}]],
               tableHeaderRows = []})))
diff --git a/haddock-library/fixtures/examples/table5.parsed b/haddock-library/fixtures/examples/table5.parsed
index 9a547ad3..f9a387bb 100644
--- a/haddock-library/fixtures/examples/table5.parsed
+++ b/haddock-library/fixtures/examples/table5.parsed
@@ -4,50 +4,43 @@ DocTable
                         [TableCell
                            {tableCellColspan = 1,
                             tableCellContents = DocString
-                                                  (concat
-                                                     [" row 2        \n",
-                                                      "              \n",
-                                                      "              \n",
-                                                      " row 3        "]),
+                                                  (concat ["row 2\n", "\n", "\n", "row 3"]),
                             tableCellRowspan = 2},
                          TableCell
                            {tableCellColspan = 3,
                             tableCellContents = DocAppend
-                                                  (DocString " Use the command  ")
+                                                  (DocString "Use the command  ")
                                                   (DocAppend
                                                      (DocMonospaced (DocString "ls | more"))
-                                                     (DocString
-                                                        (concat
-                                                           [".    \n",
-                                                            "                                  "]))),
+                                                     (DocString ".\n")),
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "          ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}]],
      tableHeaderRows = [TableRow
                           [TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " row 1, col 1 ",
+                              tableCellContents = DocString "row 1, col 1",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " column 2 ",
+                              tableCellContents = DocString "column 2",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " column 3  ",
+                              tableCellContents = DocString "column 3",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " column 4  ",
+                              tableCellContents = DocString "column 4",
                               tableCellRowspan = 1}]]}
diff --git a/haddock-library/src/Documentation/Haddock/Parser.hs b/haddock-library/src/Documentation/Haddock/Parser.hs
index 028422a7..17240792 100644
--- a/haddock-library/src/Documentation/Haddock/Parser.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser.hs
@@ -267,7 +267,7 @@ picture = DocPic . makeLabeled Picture
 -- >>> parseString "\\(\\int_{-\\infty}^{\\infty} e^{-x^2/2} = \\sqrt{2\\pi}\\)"
 -- DocMathInline "\\int_{-\\infty}^{\\infty} e^{-x^2/2} = \\sqrt{2\\pi}"
 mathInline :: Parser (DocH mod a)
-mathInline = DocMathInline . T.unpack 
+mathInline = DocMathInline . T.unpack
              <$> disallowNewline  ("\\(" *> takeUntil "\\)")
 
 -- | Display math parser, surrounded by \\[ and \\].
@@ -492,7 +492,7 @@ tableStepFour rs hdrIndex cells =  case hdrIndex of
     -- extract cell contents given boundaries
     extract :: Int -> Int -> Int -> Int -> Text
     extract x y x2 y2 = T.intercalate "\n"
-        [ T.take (x2 - x + 1) $ T.drop x $ rs !! y'
+        [ T.stripEnd $ T.stripStart $ T.take (x2 - x + 1) $ T.drop x $ rs !! y'
         | y' <- [y .. y2]
         ]
 
@@ -579,7 +579,7 @@ definitionList indent = DocDefList <$> p
         Right i -> (label, contents) : i
 
 -- | Drops all trailing newlines.
-dropNLs :: Text -> Text 
+dropNLs :: Text -> Text
 dropNLs = T.dropWhileEnd (== '\n')
 
 -- | Main worker for 'innerList' and 'definitionList'.
@@ -653,7 +653,7 @@ takeNonEmptyLine = do
 --
 -- More precisely: skips all whitespace-only lines and returns indentation
 -- (horizontal space, might be empty) of that non-empty line.
-takeIndent :: Parser Text 
+takeIndent :: Parser Text
 takeIndent = do
   indent <- takeHorizontalSpace
   choice' [ "\n" *> takeIndent
@@ -711,14 +711,14 @@ examples = DocExamples <$> (many (try (skipHorizontalSpace *> "\n")) *> go)
         substituteBlankLine "<BLANKLINE>" = ""
         substituteBlankLine xs = xs
 
-nonEmptyLine :: Parser Text 
+nonEmptyLine :: Parser Text
 nonEmptyLine = try (mfilter (T.any (not . isSpace)) takeLine)
 
 takeLine :: Parser Text
 takeLine = try (takeWhile (/= '\n') <* endOfLine)
 
 endOfLine :: Parser ()
-endOfLine = void "\n" <|> Parsec.eof 
+endOfLine = void "\n" <|> Parsec.eof
 
 -- | Property parser.
 --
@@ -800,7 +800,7 @@ autoUrl :: Parser (DocH mod a)
 autoUrl = mkLink <$> url
   where
     url = mappend <$> choice' [ "http://", "https://", "ftp://"] <*> takeWhile1 (not . isSpace)
-    
+
     mkLink :: Text -> DocH mod a
     mkLink s = case T.unsnoc s of
       Just (xs,x) | x `elem` (",.!?" :: String) -> DocHyperlink (mkHyperlink xs) `docAppend` DocString [x]