feat: improve table support for all conceal levels

## Details

Currently if users change the conceallevel from the non default value
they were likely to experience problems with table rendering. Level 2
would likely function just as well as the default of 3, but 0 and 1
required some modifications.

Level 0, concealing is entirely disabled:

- Alignment according to indicator is impossible, text cannot be shifted
- Rather than shifting text add a special case and right pad cells based
  on the amount of filler needed to get spaces to align
- The width calculation required no changes

Level 1, concealed blocks display a single character:

- Alignment according to indicator is possible, but we need to conceal
  an additional character to account for the one that gets added
- Width calculation must mark one less character as concealed per block

Add unit tests to validate behavior.

Author: MeanderingProgrammer

Diff for: lua/render-markdown/core/context.lua

@@ -4,16 +4,21 @@ local Str = require('render-markdown.lib.str')
 local log = require('render-markdown.core.log')
 local util = require('render-markdown.core.util')
 
+---@class render.md.context.Conceal
+---@field enabled boolean
+---@field block integer
+---@field rows? table<integer, [integer, integer][]>
+
 ---@class render.md.Context
 ---@field private buf integer
 ---@field private win integer
 ---@field private ranges render.md.Range[]
 ---@field private callouts table<integer, render.md.CustomCallout>
 ---@field private checkboxes table<integer, render.md.CustomCheckbox>
----@field private conceal? table<integer, [integer, integer][]>
 ---@field private links table<integer, [integer, integer, integer][]>
 ---@field private window_width? integer
 ---@field mode string
+---@field conceal render.md.context.Conceal
 ---@field last_heading? integer
 local Context = {}
 Context.__index = Context
@@ -28,20 +33,26 @@ function Context.new(buf, win, mode, offset)
     self.buf = buf
     self.win = win
 
-    local ranges = { Context.compute_range(self.buf, self.win, offset) }
+    local ranges = {}
     for _, window in ipairs(util.windows(buf)) do
-        if window ~= self.win then
-            table.insert(ranges, Context.compute_range(self.buf, window, offset))
-        end
+        table.insert(ranges, Context.compute_range(self.buf, window, offset))
     end
     self.ranges = Range.coalesce(ranges)
 
     self.callouts = {}
     self.checkboxes = {}
-    self.conceal = nil
     self.links = {}
     self.window_width = nil
     self.mode = mode
+
+    local conceal_level = util.get('win', self.win, 'conceallevel')
+    self.conceal = {
+        enabled = conceal_level > 0,
+        -- At conceal level 1 each block is replaced with one character
+        block = conceal_level == 1 and 1 or 0,
+        rows = nil,
+    }
+
     self.last_heading = nil
     return self
 end
@@ -93,7 +104,7 @@ end
 
 ---@return integer
 function Context:tab_size()
-    return util.get('buf', self.buf, 'tabstop') --[[@as integer]]
+    return util.get('buf', self.buf, 'tabstop')
 end
 
 ---@param node? render.md.Node
@@ -215,9 +226,12 @@ function Context:concealed(node)
     for _, index in ipairs(vim.fn.str2list(node.text)) do
         local ch = vim.fn.nr2char(index)
         for _, range in ipairs(ranges) do
-            -- Essentially vim.treesitter.is_in_node_range but only care about column
+            -- Column level implementation of vim.treesitter.is_in_node_range
             if col >= range[1] and col + 1 <= range[2] then
                 result = result + Str.width(ch)
+                if col == range[1] then
+                    result = result - self.conceal.block
+                end
             end
         end
         col = col + #ch
@@ -229,18 +243,17 @@ end
 ---@param row integer
 ---@return [integer, integer][]
 function Context:get_conceal(row)
-    if self.conceal == nil then
-        self.conceal = self:compute_conceal()
+    if self.conceal.rows == nil then
+        self.conceal.rows = self:compute_conceal()
     end
-    return self.conceal[row] or {}
+    return self.conceal.rows[row] or {}
 end
 
 ---Cached row level implementation of vim.treesitter.get_captures_at_pos
 ---@private
 ---@return table<integer, [integer, integer][]>
 function Context:compute_conceal()
-    local conceallevel = util.get('win', self.win, 'conceallevel')
-    if conceallevel == 0 then
+    if not self.conceal.enabled then
         return {}
     end
     local ranges = {}

Diff for: lua/render-markdown/core/util.lua

@@ -76,6 +76,11 @@ end
 ---@param id integer
 ---@param name string
 ---@return render.md.option.Value
+---@overload fun(variant: 'buf', id: integer, name: 'buftype'): string
+---@overload fun(variant: 'buf', id: integer, name: 'filetype'): string
+---@overload fun(variant: 'buf', id: integer, name: 'tabstop'): integer
+---@overload fun(variant: 'win', id: integer, name: 'conceallevel'): integer
+---@overload fun(variant: 'win', id: integer, name: 'diff'): boolean
 function M.get(variant, id, name)
     if variant == 'buf' then
         return vim.api.nvim_get_option_value(name, { buf = id })

Diff for: lua/render-markdown/health.lua

@@ -4,7 +4,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '7.5.2'
+M.version = '7.5.3'
 
 function M.check()
     M.start('version')

Diff for: lua/render-markdown/init.lua

@@ -25,7 +25,7 @@ local M = {}
 ---@field public enabled? boolean
 ---@field public query? string
 
----@alias render.md.option.Value number|string|boolean
+---@alias render.md.option.Value number|integer|string|boolean
 
 ---@class (exact) render.md.UserWindowOption
 ---@field public default? render.md.option.Value

Diff for: lua/render-markdown/render/table.lua

@@ -45,7 +45,10 @@ function Render:setup()
         return false
     end
 
-    local delim, table_rows = nil, {}
+    ---@type render.md.table.DelimRow?
+    local delim = nil
+    ---@type render.md.Node[]
+    local table_rows = {}
     self.node:for_each_child(function(row)
         if row.type == 'pipe_table_delimiter_row' then
             delim = self:parse_delim(row)
@@ -57,11 +60,13 @@ function Render:setup()
             end
         end
     end)
+
     -- Ensure delimiter and rows exist for table
     if delim == nil or #table_rows == 0 then
         return false
     end
 
+    ---@type render.md.table.Row[]
     local rows = {}
     table.sort(table_rows)
     for _, table_row in ipairs(table_rows) do
@@ -70,14 +75,16 @@ function Render:setup()
             table.insert(rows, row)
         end
     end
-    -- Store the max width information in the delimiter
+
+    -- Store the max width in the delimiter
     for _, row in ipairs(rows) do
         for i, column in ipairs(row.columns) do
-            local delim_column, width = delim.columns[i], column.width
+            local width = column.width
             if self.table.cell == 'trimmed' then
                 local space_available = column.space.left + column.space.right - (2 * self.table.padding)
                 width = width - math.max(space_available, 0)
             end
+            local delim_column = delim.columns[i]
             delim_column.width = math.max(delim_column.width, width)
         end
     end
@@ -95,6 +102,7 @@ function Render:parse_delim(row)
     if pipes == nil or cells == nil then
         return nil
     end
+    ---@type render.md.table.DelimColumn[]
     local columns = {}
     for i, cell in ipairs(cells) do
         local width = pipes[i + 1].start_col - pipes[i].end_col
@@ -106,22 +114,25 @@ function Render:parse_delim(row)
         elseif self.table.cell == 'trimmed' then
             width = self.table.min_width
         end
-        table.insert(columns, { width = width, alignment = Render.alignment(cell) })
+        ---@type render.md.table.DelimColumn
+        local column = { width = width, alignment = Render.alignment(cell) }
+        table.insert(columns, column)
     end
+    ---@type render.md.table.DelimRow
     return { node = row, columns = columns }
 end
 
 ---@private
----@param cell render.md.Node
+---@param node render.md.Node
 ---@return render.md.table.Alignment
-function Render.alignment(cell)
-    local align_left = cell:child('pipe_table_align_left') ~= nil
-    local align_right = cell:child('pipe_table_align_right') ~= nil
-    if align_left and align_right then
+function Render.alignment(node)
+    local has_left = node:child('pipe_table_align_left') ~= nil
+    local has_right = node:child('pipe_table_align_right') ~= nil
+    if has_left and has_right then
         return 'center'
-    elseif align_left then
+    elseif has_left then
         return 'left'
-    elseif align_right then
+    elseif has_right then
         return 'right'
     else
         return 'default'
@@ -137,6 +148,7 @@ function Render:parse_row(row, num_columns)
     if pipes == nil or cells == nil or #cells ~= num_columns then
         return nil
     end
+    ---@type render.md.table.Column[]
     local columns = {}
     for i, cell in ipairs(cells) do
         local start_col, end_col = pipes[i].end_col, pipes[i + 1].start_col
@@ -152,14 +164,17 @@ function Render:parse_row(row, num_columns)
         if width < 0 then
             return nil
         end
-        table.insert(columns, {
+        ---@type render.md.table.Column
+        local column = {
             row = cell.start_row,
             start_col = cell.start_col,
             end_col = cell.end_col,
             width = width,
             space = space,
-        })
+        }
+        table.insert(columns, column)
     end
+    ---@type render.md.table.Row
     return { node = row, pipes = pipes, columns = columns }
 end
 
@@ -200,20 +215,20 @@ end
 function Render:delimiter()
     local delim, border = self.data.delim, self.table.border
 
+    local indicator, icon = self.table.alignment_indicator, border[11]
     local sections = Iter.list.map(delim.columns, function(column)
-        local indicator, box = self.table.alignment_indicator, border[11]
         -- If column is small there's no good place to put the alignment indicator
         -- Alignment indicator must be exactly one character wide
         -- Do not put an indicator for default alignment
         if column.width < 3 or Str.width(indicator) ~= 1 or column.alignment == 'default' then
-            return box:rep(column.width)
+            return icon:rep(column.width)
         end
         if column.alignment == 'left' then
-            return indicator .. box:rep(column.width - 1)
+            return indicator .. icon:rep(column.width - 1)
         elseif column.alignment == 'right' then
-            return box:rep(column.width - 1) .. indicator
+            return icon:rep(column.width - 1) .. indicator
         else
-            return indicator .. box:rep(column.width - 2) .. indicator
+            return indicator .. icon:rep(column.width - 2) .. indicator
         end
     end)
 
@@ -250,7 +265,10 @@ function Render:row(row)
         for i, column in ipairs(row.columns) do
             local delim_column = delim.columns[i]
             local filler = delim_column.width - column.width
-            if delim_column.alignment == 'center' then
+            if not self.context.conceal.enabled then
+                -- Without concealing it is impossible to do full alignment
+                self:shift(column, 'right', filler)
+            elseif delim_column.alignment == 'center' then
                 local shift = math.floor((filler + column.space.right - column.space.left) / 2)
                 self:shift(column, 'left', shift)
                 self:shift(column, 'right', filler - shift)
@@ -290,6 +308,7 @@ function Render:shift(column, side, amount)
             virt_text_pos = 'inline',
         })
     elseif amount < 0 then
+        amount = amount - self.context.conceal.block
         self.marks:add(true, column.row, col + amount, {
             priority = 0,
             end_col = col,

Diff for: tests/table_spec.lua

@@ -225,4 +225,48 @@ describe('table.md', function()
             '      └───────────┴───────────┘',
         })
     end)
+
+    it('conceallevel 0', function()
+        util.setup('tests/data/table.md', { win_options = { conceallevel = { rendered = 0 } } })
+
+        util.assert_screen({
+            '󰫎   1 󰲡 Table with Inline',
+            '    2',
+            '      ┌───────────┬──────────────────────────┐',
+            '    3 │ Heading 1 │ `Heading 2`              │',
+            '    4 ├───────────┼─────────────────────────━┤',
+            '    5 │ `Item 行` │ 󰖟 [link](https://行.com) │',
+            '      └───────────┴──────────────────────────┘',
+            '    6',
+            '󰫎   7 󰲡 Table no Inline',
+            '    8',
+            '      ┌───────────┬───────────┐',
+            '    9 │ Heading 1 │ Heading 2 │',
+            '   10 ├───────────┼───────────┤',
+            '   11 │ Item 1    │ Item 2    │',
+            '      └───────────┴───────────┘',
+        })
+    end)
+
+    it('conceallevel 1', function()
+        util.setup('tests/data/table.md', { win_options = { conceallevel = { rendered = 1 } } })
+
+        util.assert_screen({
+            '󰫎   1 󰲡 Table with Inline',
+            '    2',
+            '      ┌───────────┬────────────────────────┐',
+            '    3 │ Heading 1 │             Heading 2  │',
+            '    4 ├───────────┼───────────────────────━┤',
+            '    5 │  Item 行  │            󰖟  link     │',
+            '      └───────────┴────────────────────────┘',
+            '    6',
+            '󰫎   7 󰲡 Table no Inline',
+            '    8',
+            '      ┌───────────┬───────────┐',
+            '    9 │ Heading 1 │ Heading 2 │',
+            '   10 ├───────────┼───────────┤',
+            '   11 │ Item 1    │ Item 2    │',
+            '      └───────────┴───────────┘',
+        })
+    end)
 end)