feat: allow users to disable code block delimiter concealing

## Details

Request: #475

Among the changes introduced back in `0.11.0`, how the delimiter nodes
around code blocks were handled was one them. Rather than a horizontal
conceal a new vertical conceal was added which entirely removed those
lines if conceal was enabled.

In order to still allow borders to be rendered I needed a way to disable
this feature while still allowing for concealing elsewhere. Luckily in
the set of changes a way to dynamically turn off certain highlights was
also added, which we use at startup to disable this behavior for users.

While fixing all the odds and ends I decided to replicate the old
behavior and apply a horizontal conceal over the various delimiter
nodes, I didn't give much thought towards other approaches.

This feature allows users who want those delimiter elements to still
have them. To make this happen the following new options have been added:

- `code.conceal_delimiters` - stops us from adding conceal over the
  delimiter nodes if set to `false`
- `code.language` - a more direct way to disable language headings,
  functionally the same as `style = 'normal'`

To get the backticks back these 2 must be set properly and `border` must
also be disabled. This removes all the things that currently cover these
nodes, final config ends up as:

```lua
require('render-markdown').setup({
    code = {
        conceal_delimiters = false,
        language = false,
        border = 'none',
    },
})
```

Author: MeanderingProgrammer

README.md

@@ -435,24 +435,28 @@ require('render-markdown').setup({
         -- Turn on / off any sign column related rendering.
         sign = true,
         -- Determines how code blocks & inline code are rendered.
-        -- | none     | disables all rendering                                                    |
-        -- | normal   | highlight group to code blocks & inline code, adds padding to code blocks |
-        -- | language | language icon to sign column if enabled and icon + name above code blocks |
-        -- | full     | normal + language                                                         |
+        -- | none     | disables all rendering                   |
+        -- | normal   | background highlighting + padding        |
+        -- | language | language heading with icon + sign column |
+        -- | full     | normal + language                        |
         style = 'full',
+        -- Whether to conceal nodes at the top and bottom of code blocks.
+        conceal_delimiters = true,
+        -- Turn on / off any language heading related rendering.
+        language = true,
         -- Determines where language icon is rendered.
         -- | right | right side of code block |
         -- | left  | left side of code block  |
         position = 'left',
-        -- Amount of padding to add around the language.
-        -- If a float < 1 is provided it is treated as a percentage of available window space.
-        language_pad = 0,
         -- Whether to include the language icon above code blocks.
         language_icon = true,
         -- Whether to include the language name above code blocks.
         language_name = true,
         -- Whether to include the language info above code blocks.
         language_info = true,
+        -- Amount of padding to add around the language.
+        -- If a float < 1 is provided it is treated as a percentage of available window space.
+        language_pad = 0,
         -- A list of language names for which background highlighting will be disabled.
         -- Likely because that language has background highlights itself.
         -- Use a boolean to make behavior apply to all languages.
@@ -1058,24 +1062,28 @@ require('render-markdown').setup({
         -- Turn on / off any sign column related rendering.
         sign = true,
         -- Determines how code blocks & inline code are rendered.
-        -- | none     | disables all rendering                                                    |
-        -- | normal   | highlight group to code blocks & inline code, adds padding to code blocks |
-        -- | language | language icon to sign column if enabled and icon + name above code blocks |
-        -- | full     | normal + language                                                         |
+        -- | none     | disables all rendering                   |
+        -- | normal   | background highlighting + padding        |
+        -- | language | language heading with icon + sign column |
+        -- | full     | normal + language                        |
         style = 'full',
+        -- Whether to conceal nodes at the top and bottom of code blocks.
+        conceal_delimiters = true,
+        -- Turn on / off any language heading related rendering.
+        language = true,
         -- Determines where language icon is rendered.
         -- | right | right side of code block |
         -- | left  | left side of code block  |
         position = 'left',
-        -- Amount of padding to add around the language.
-        -- If a float < 1 is provided it is treated as a percentage of available window space.
-        language_pad = 0,
         -- Whether to include the language icon above code blocks.
         language_icon = true,
         -- Whether to include the language name above code blocks.
         language_name = true,
         -- Whether to include the language info above code blocks.
         language_info = true,
+        -- Amount of padding to add around the language.
+        -- If a float < 1 is provided it is treated as a percentage of available window space.
+        language_pad = 0,
         -- A list of language names for which background highlighting will be disabled.
         -- Likely because that language has background highlights itself.
         -- Use a boolean to make behavior apply to all languages.

doc/render-markdown.txt

@@ -1,4 +1,4 @@
-*render-markdown.txt*        For NVIM v0.11.2        Last change: 2025 July 15
+*render-markdown.txt*        For NVIM v0.11.3        Last change: 2025 July 17
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*
@@ -501,24 +501,28 @@ Default Configuration ~
             -- Turn on / off any sign column related rendering.
             sign = true,
             -- Determines how code blocks & inline code are rendered.
-            -- | none     | disables all rendering                                                    |
-            -- | normal   | highlight group to code blocks & inline code, adds padding to code blocks |
-            -- | language | language icon to sign column if enabled and icon + name above code blocks |
-            -- | full     | normal + language                                                         |
+            -- | none     | disables all rendering                   |
+            -- | normal   | background highlighting + padding        |
+            -- | language | language heading with icon + sign column |
+            -- | full     | normal + language                        |
             style = 'full',
+            -- Whether to conceal nodes at the top and bottom of code blocks.
+            conceal_delimiters = true,
+            -- Turn on / off any language heading related rendering.
+            language = true,
             -- Determines where language icon is rendered.
             -- | right | right side of code block |
             -- | left  | left side of code block  |
             position = 'left',
-            -- Amount of padding to add around the language.
-            -- If a float < 1 is provided it is treated as a percentage of available window space.
-            language_pad = 0,
             -- Whether to include the language icon above code blocks.
             language_icon = true,
             -- Whether to include the language name above code blocks.
             language_name = true,
             -- Whether to include the language info above code blocks.
             language_info = true,
+            -- Amount of padding to add around the language.
+            -- If a float < 1 is provided it is treated as a percentage of available window space.
+            language_pad = 0,
             -- A list of language names for which background highlighting will be disabled.
             -- Likely because that language has background highlights itself.
             -- Use a boolean to make behavior apply to all languages.
@@ -1118,24 +1122,28 @@ Code Block Configuration ~
             -- Turn on / off any sign column related rendering.
             sign = true,
             -- Determines how code blocks & inline code are rendered.
-            -- | none     | disables all rendering                                                    |
-            -- | normal   | highlight group to code blocks & inline code, adds padding to code blocks |
-            -- | language | language icon to sign column if enabled and icon + name above code blocks |
-            -- | full     | normal + language                                                         |
+            -- | none     | disables all rendering                   |
+            -- | normal   | background highlighting + padding        |
+            -- | language | language heading with icon + sign column |
+            -- | full     | normal + language                        |
             style = 'full',
+            -- Whether to conceal nodes at the top and bottom of code blocks.
+            conceal_delimiters = true,
+            -- Turn on / off any language heading related rendering.
+            language = true,
             -- Determines where language icon is rendered.
             -- | right | right side of code block |
             -- | left  | left side of code block  |
             position = 'left',
-            -- Amount of padding to add around the language.
-            -- If a float < 1 is provided it is treated as a percentage of available window space.
-            language_pad = 0,
             -- Whether to include the language icon above code blocks.
             language_icon = true,
             -- Whether to include the language name above code blocks.
             language_name = true,
             -- Whether to include the language info above code blocks.
             language_info = true,
+            -- Amount of padding to add around the language.
+            -- If a float < 1 is provided it is treated as a percentage of available window space.
+            language_pad = 0,
             -- A list of language names for which background highlighting will be disabled.
             -- Likely because that language has background highlights itself.
             -- Use a boolean to make behavior apply to all languages.

lua/render-markdown/config/code.lua

@@ -1,11 +1,13 @@
 ---@class (exact) render.md.code.Config: render.md.base.Config
 ---@field sign boolean
 ---@field style render.md.code.Style
+---@field conceal_delimiters boolean
+---@field language boolean
 ---@field position render.md.code.Position
----@field language_pad number
 ---@field language_icon boolean
 ---@field language_name boolean
 ---@field language_info boolean
+---@field language_pad number
 ---@field disable_background boolean|string[]
 ---@field width render.md.code.Width
 ---@field left_margin number
@@ -68,24 +70,28 @@ M.default = {
     -- Turn on / off any sign column related rendering.
     sign = true,
     -- Determines how code blocks & inline code are rendered.
-    -- | none     | disables all rendering                                                    |
-    -- | normal   | highlight group to code blocks & inline code, adds padding to code blocks |
-    -- | language | language icon to sign column if enabled and icon + name above code blocks |
-    -- | full     | normal + language                                                         |
+    -- | none     | disables all rendering                   |
+    -- | normal   | background highlighting + padding        |
+    -- | language | language heading with icon + sign column |
+    -- | full     | normal + language                        |
     style = 'full',
+    -- Whether to conceal nodes at the top and bottom of code blocks.
+    conceal_delimiters = true,
+    -- Turn on / off any language heading related rendering.
+    language = true,
     -- Determines where language icon is rendered.
     -- | right | right side of code block |
     -- | left  | left side of code block  |
     position = 'left',
-    -- Amount of padding to add around the language.
-    -- If a float < 1 is provided it is treated as a percentage of available window space.
-    language_pad = 0,
     -- Whether to include the language icon above code blocks.
     language_icon = true,
     -- Whether to include the language name above code blocks.
     language_name = true,
     -- Whether to include the language info above code blocks.
     language_info = true,
+    -- Amount of padding to add around the language.
+    -- If a float < 1 is provided it is treated as a percentage of available window space.
+    language_pad = 0,
     -- A list of language names for which background highlighting will be disabled.
     -- Likely because that language has background highlights itself.
     -- Use a boolean to make behavior apply to all languages.
@@ -148,11 +154,13 @@ function M.validate(spec)
     require('render-markdown.config.base').validate(spec)
     spec:type('sign', 'boolean')
     spec:one_of('style', vim.tbl_values(Style))
+    spec:type('conceal_delimiters', 'boolean')
+    spec:type('language', 'boolean')
     spec:one_of('position', vim.tbl_values(Position))
-    spec:type('language_pad', 'number')
     spec:type('language_icon', 'boolean')
     spec:type('language_name', 'boolean')
     spec:type('language_info', 'boolean')
+    spec:type('language_pad', 'number')
     spec:list('disable_background', 'string', 'boolean')
     spec:one_of('width', vim.tbl_values(Width))
     spec:type('left_margin', 'number')

lua/render-markdown/health.lua

@@ -5,7 +5,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '8.6.4'
+M.version = '8.6.5'
 
 function M.check()
     M.start('version')

lua/render-markdown/render/markdown/code.lua

@@ -72,15 +72,17 @@ end
 ---@protected
 function Render:run()
     local start_row = self.node.start_row
-    local above = self.node:child('fenced_code_block_delimiter', start_row)
-    self.marks:over(true, above, { conceal = '' })
-
     local end_row = self.node.end_row - 1
-    local below = self.node:child('fenced_code_block_delimiter', end_row)
-    self.marks:over(true, below, { conceal = '' })
 
+    local above = self.node:child('fenced_code_block_delimiter', start_row)
+    local below = self.node:child('fenced_code_block_delimiter', end_row)
     local info = self.node:child('info_string')
-    self.marks:over(true, info, { conceal = '' })
+
+    if self.config.conceal_delimiters then
+        self.marks:over(true, above, { conceal = '' })
+        self.marks:over(true, below, { conceal = '' })
+        self.marks:over(true, info, { conceal = '' })
+    end
 
     local language = info and info:child('language')
     if not self:language(info, language, above) then
@@ -104,6 +106,9 @@ function Render:language(info, language, delim)
     if not vim.tbl_contains({ 'language', 'full' }, self.config.style) then
         return false
     end
+    if not self.config.language then
+        return false
+    end
     if not info or not language or not delim then
         return false
     end

lua/render-markdown/types.lua

@@ -86,11 +86,13 @@
 ---@class (exact) render.md.code.UserConfig: render.md.base.UserConfig
 ---@field sign? boolean
 ---@field style? render.md.code.Style
+---@field conceal_delimiters? boolean
+---@field language? boolean
 ---@field position? render.md.code.Position
----@field language_pad? number
 ---@field language_icon? boolean
 ---@field language_name? boolean
 ---@field language_info? boolean
+---@field language_pad? number
 ---@field disable_background? boolean|string[]
 ---@field width? render.md.code.Width
 ---@field left_margin? number