feat: better anti-conceal for multi-line decorations

## Details

Previously only the starting row of a mark would be used when deciding
whether the mark should be hidden or shown. This means if a mark spanned
multiple rows (like with scope highlights) we would only hide the
decoration if the users cursor was on the first line, but show it when
the cursor was anywhere in the middle.

This is okay, but definitely not ideal, so now the logic uses both the
start and end row of a mark and hides it if the current row overlaps the
mark. We use overlap since in visual mode it is not a single row, but
multiple. Now any overlapping marks within the cursor range are hidden.

There is a special case for `hl_eol` marks, which specify an end row but
do not actually impact that row, instead their impact effectively ends
one row earlier. So we handle this case specifically and offset the end
of a mark by 1 if `hl_eol` is specified. Hopefully there are no other
such edge cases.

Minor other changes:

- Add unit tests for `range` class
- Rename `render.md.Renderer` to `render.md.Render`
- Match order of fields in `default_buffer_config()` with class

Author: MeanderingProgrammer

Diff for: benches/medium_table_spec.lua

@@ -4,7 +4,7 @@ local util = require('benches.util')
 
 describe('medium-table.md', function()
     it('default', function()
-        local base_marks = 337
+        local base_marks = 341
         util.less_than(util.setup('temp/medium-table.md'), 120)
         util.num_marks(base_marks)
 

Diff for: benches/util.lua

@@ -1,7 +1,7 @@
 ---@module 'luassert'
 
-local eq = assert.are.same
-local truthy = assert.truthy
+local Eq = assert.are.same
+local True = assert.True
 
 ---@class render.md.bench.Util
 local M = {}
@@ -52,14 +52,14 @@ end
 ---@param actual number
 ---@param max number
 function M.less_than(actual, max)
-    truthy(actual < max, string.format('expected %f < %f', actual, max))
+    True(actual < max, string.format('expected %f < %f', actual, max))
 end
 
 ---@param expected integer
 function M.num_marks(expected)
     local ui = require('render-markdown.core.ui')
     local marks = vim.api.nvim_buf_get_extmarks(0, ui.ns, 0, -1, {})
-    eq(expected, #marks)
+    Eq(expected, #marks)
 end
 
 return M

Diff for: doc/render-markdown.txt

@@ -1,4 +1,4 @@
-*render-markdown.txt*           For 0.11.0          Last change: 2025 April 11
+*render-markdown.txt*           For 0.11.0          Last change: 2025 April 15
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*

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

@@ -119,7 +119,7 @@ end
 ---@return render.md.Range?
 function Config:hidden(mode, row)
     -- Anti-conceal is not enabled -> hide nothing
-    -- Row is not known means buffer is not active -> hide nothing
+    -- Row is not known -> buffer is not active -> hide nothing
     if not self.anti_conceal.enabled or row == nil then
         return nil
     end

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

@@ -22,12 +22,17 @@ end
 
 ---@param range? render.md.Range
 ---@return boolean
-function Extmark:inside(range)
+function Extmark:overlaps(range)
     if range == nil then
         return false
     end
-    local row = self.mark.start_row
-    return range:contains(row, row)
+    local top = self.mark.start_row
+    local bottom = self.mark.opts.end_row or top
+    -- overlap for hl_eol should not include last line
+    if self.mark.opts.hl_eol then
+        bottom = bottom - 1
+    end
+    return range:overlaps(top, bottom)
 end
 
 ---@param ns integer

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

@@ -36,7 +36,7 @@ end
 ---@param bottom integer
 ---@return boolean
 function Range:overlaps(top, bottom)
-    return top < self.bottom and bottom >= self.top
+    return top <= self.bottom and bottom >= self.top
 end
 
 ---@param ranges render.md.Range[]

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

@@ -64,7 +64,7 @@ function M.get_row_marks(buf, win)
 
     local marks = {}
     for _, extmark in ipairs(buffer:get_marks()) do
-        if extmark:inside(hidden) then
+        if extmark:overlaps(hidden) then
             marks[#marks + 1] = extmark:get()
         end
     end
@@ -167,7 +167,7 @@ function M.run_update(buf, win, change)
             state.on.initial({ buf = buf, win = win })
         end
         for _, extmark in ipairs(extmarks) do
-            if extmark:get().conceal and extmark:inside(hidden) then
+            if extmark:get().conceal and extmark:overlaps(hidden) then
                 extmark:hide(M.ns, buf)
             else
                 extmark:show(M.ns, buf)

Diff for: lua/render-markdown/debug/marks.lua

@@ -56,7 +56,7 @@ end
 ---@return string
 function Mark:__tostring()
     local lines = {}
-    lines[#lines + 1] = string.rep('=', vim.o.columns - 10)
+    lines[#lines + 1] = string.rep('=', vim.o.columns - 1)
     lines[#lines + 1] = string.format('row: %s', Mark.collapse(self.row))
     lines[#lines + 1] = string.format('column: %s', Mark.collapse(self.col))
     lines[#lines + 1] = string.format('hide: %s', vim.inspect(self.conceal))

Diff for: lua/render-markdown/handler/html.lua

@@ -8,7 +8,7 @@ local ts = require('render-markdown.integ.ts')
 ---@field private context render.md.Context
 ---@field private marks render.md.Marks
 ---@field private query vim.treesitter.Query
----@field private renderers table<string, render.md.Renderer>
+---@field private renderers table<string, render.md.Render>
 local Handler = {}
 Handler.__index = Handler
 

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

@@ -8,7 +8,7 @@ local ts = require('render-markdown.integ.ts')
 ---@field private context render.md.Context
 ---@field private marks render.md.Marks
 ---@field private query vim.treesitter.Query
----@field private renderers table<string, render.md.Renderer>
+---@field private renderers table<string, render.md.Render>
 local Handler = {}
 Handler.__index = Handler
 

Diff for: lua/render-markdown/handler/markdown_inline.lua

@@ -8,7 +8,7 @@ local ts = require('render-markdown.integ.ts')
 ---@field private context render.md.Context
 ---@field private marks render.md.Marks
 ---@field private query vim.treesitter.Query
----@field private renderers table<string, render.md.Renderer>
+---@field private renderers table<string, render.md.Render>
 local Handler = {}
 Handler.__index = Handler
 

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

@@ -5,7 +5,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '8.2.10'
+M.version = '8.2.11'
 
 function M.check()
     M.start('version')

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

@@ -2,21 +2,21 @@ local Iter = require('render-markdown.lib.iter')
 local Str = require('render-markdown.lib.str')
 local colors = require('render-markdown.colors')
 
----@class render.md.Renderer
+---@class render.md.Render
 ---@field protected marks render.md.Marks
 ---@field protected config render.md.BufferConfig
 ---@field protected context render.md.Context
 ---@field protected node render.md.Node
----@field setup fun(self: render.md.Renderer): boolean
----@field render fun(self: render.md.Renderer)
+---@field setup fun(self: render.md.Render): boolean
+---@field render fun(self: render.md.Render)
 local Base = {}
 Base.__index = Base
 
 ---@param marks render.md.Marks
 ---@param config render.md.BufferConfig
 ---@param context render.md.Context
 ---@param node render.md.Node
----@return render.md.Renderer
+---@return render.md.Render
 function Base:new(marks, config, context, node)
     local instance = setmetatable({}, self)
     instance.marks = marks

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

@@ -8,7 +8,7 @@ local Str = require('render-markdown.lib.str')
 ---@field spaces integer
 ---@field checkbox? render.md.checkbox.custom.Config
 
----@class render.md.render.ListMarker: render.md.Renderer
+---@class render.md.render.Bullet: render.md.Render
 ---@field private info render.md.bullet.Config
 ---@field private data render.md.bullet.Data
 local Render = setmetatable({}, Base)

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

@@ -1,6 +1,6 @@
 local Base = require('render-markdown.render.base')
 
----@class render.md.render.Checkbox: render.md.Renderer
+---@class render.md.render.Checkbox: render.md.Render
 ---@field private info render.md.checkbox.component.Config
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -10,7 +10,7 @@ local colors = require('render-markdown.colors')
 ---@field margin integer
 ---@field indent integer
 
----@class render.md.render.Code: render.md.Renderer
+---@class render.md.render.Code: render.md.Render
 ---@field private info render.md.code.Config
 ---@field private data render.md.code.Data
 local Render = setmetatable({}, Base)

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

@@ -1,7 +1,7 @@
 local Base = require('render-markdown.render.base')
 local colors = require('render-markdown.colors')
 
----@class render.md.render.CodeInline: render.md.Renderer
+---@class render.md.render.CodeInline: render.md.Render
 ---@field private info render.md.code.Config
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -1,6 +1,6 @@
 local Base = require('render-markdown.render.base')
 
----@class render.md.render.Dash: render.md.Renderer
+---@class render.md.render.Dash: render.md.Render
 ---@field private info render.md.dash.Config
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -23,7 +23,7 @@ local colors = require('render-markdown.colors')
 ---@field padding integer
 ---@field content integer
 
----@class render.md.render.Heading: render.md.Renderer
+---@class render.md.render.Heading: render.md.Render
 ---@field private info render.md.heading.Config
 ---@field private data render.md.heading.Data
 local Render = setmetatable({}, Base)

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

@@ -1,6 +1,6 @@
 local Base = require('render-markdown.render.base')
 
----@class render.md.render.html.Comment: render.md.Renderer
+---@class render.md.render.html.Comment: render.md.Render
 ---@field private info render.md.html.comment.Config
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -1,6 +1,6 @@
 local Base = require('render-markdown.render.base')
 
----@class render.md.render.html.Tag: render.md.Renderer
+---@class render.md.render.html.Tag: render.md.Render
 ---@field private info render.md.html.Tag
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -1,6 +1,6 @@
 local Base = require('render-markdown.render.base')
 
----@class render.md.render.InlineHighlight: render.md.Renderer
+---@class render.md.render.InlineHighlight: render.md.Render
 ---@field private info render.md.inline.highlight.Config
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -5,7 +5,7 @@ local Base = require('render-markdown.render.base')
 ---@field highlight string
 ---@field autolink boolean
 
----@class render.md.render.Link: render.md.Renderer
+---@class render.md.render.Link: render.md.Render
 ---@field private data render.md.link.Data
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -1,6 +1,6 @@
 local Base = require('render-markdown.render.base')
 
----@class render.md.render.Paragraph: render.md.Renderer
+---@class render.md.render.Paragraph: render.md.Render
 ---@field private info render.md.paragraph.Config
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -7,7 +7,7 @@ local ts = require('render-markdown.integ.ts')
 ---@field highlight string
 ---@field repeat_linebreak? boolean
 
----@class render.md.render.Quote: render.md.Renderer
+---@class render.md.render.Quote: render.md.Render
 ---@field private data render.md.quote.Data
 local Render = setmetatable({}, Base)
 Render.__index = Render

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

@@ -1,7 +1,7 @@
 local Base = require('render-markdown.render.base')
 local Str = require('render-markdown.lib.str')
 
----@class render.md.render.Section: render.md.Renderer
+---@class render.md.render.Section: render.md.Render
 ---@field private info render.md.indent.Config
 ---@field private level_change integer
 local Render = setmetatable({}, Base)

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

@@ -2,7 +2,7 @@ local Base = require('render-markdown.render.base')
 local Converter = require('render-markdown.lib.converter')
 local Str = require('render-markdown.lib.str')
 
----@class render.md.render.Shortcut: render.md.Renderer
+---@class render.md.render.Shortcut: render.md.Render
 local Render = setmetatable({}, Base)
 Render.__index = Render
 

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

@@ -39,7 +39,7 @@ local Alignment = {
 ---@field left integer
 ---@field right integer
 
----@class render.md.render.Table: render.md.Renderer
+---@class render.md.render.Table: render.md.Render
 ---@field private info render.md.table.Config
 ---@field private data render.md.table.Data
 local Render = setmetatable({}, Base)

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

@@ -107,26 +107,26 @@ function M.default_buffer_config()
     ---@type render.md.buffer.Config
     local buffer_config = {
         enabled = true,
+        render_modes = config.render_modes,
         max_file_size = config.max_file_size,
         debounce = config.debounce,
-        render_modes = config.render_modes,
         anti_conceal = config.anti_conceal,
-        padding = config.padding,
-        heading = config.heading,
-        paragraph = config.paragraph,
-        code = config.code,
-        dash = config.dash,
         bullet = config.bullet,
-        checkbox = config.checkbox,
-        quote = config.quote,
-        pipe_table = config.pipe_table,
         callout = config.callout,
-        link = config.link,
-        sign = config.sign,
-        inline_highlight = config.inline_highlight,
+        checkbox = config.checkbox,
+        code = config.code,
+        dash = config.dash,
+        heading = config.heading,
+        html = config.html,
         indent = config.indent,
+        inline_highlight = config.inline_highlight,
         latex = config.latex,
-        html = config.html,
+        link = config.link,
+        padding = config.padding,
+        paragraph = config.paragraph,
+        pipe_table = config.pipe_table,
+        quote = config.quote,
+        sign = config.sign,
         win_options = config.win_options,
     }
     return vim.deepcopy(buffer_config)

Diff for: tests/comp_spec.lua

@@ -2,7 +2,7 @@
 
 local util = require('tests.util')
 
-local eq = assert.are.same
+local Eq = assert.are.same
 
 ---@param row integer
 ---@param col integer
@@ -13,7 +13,7 @@ local function assert_items(row, col, expected)
     table.sort(actual, function(a, b)
         return a.label < b.label
     end)
-    eq(expected, actual)
+    Eq(expected, actual)
 end
 
 ---@param prefix string

Diff for: tests/latex_spec.lua

@@ -3,20 +3,20 @@
 local stub = require('luassert.stub')
 local util = require('tests.util')
 
-local eq = assert.are.same
-local truthy = assert.truthy
+local Eq = assert.are.same
+local True = assert.True
 
 ---@param converter string
 ---@param responses table<string, string>
 local function set_responses(converter, responses)
     stub.new(vim.fn, 'executable', function(expr)
-        eq(converter, expr)
+        Eq(converter, expr)
         return 1
     end)
     stub.new(vim.fn, 'system', function(cmd, input)
-        eq(converter, cmd)
+        Eq(converter, cmd)
         local result = responses[input]
-        truthy(result, 'No output for: ' .. input)
+        True(result ~= nil, 'No output for: ' .. input)
         return result
     end)
 end