fix: lsp hover doc for neovim < 0.11.0

## Details

Follow up to the fix for 0.11.0:
b57d51d

That change ended up causing the same problem that existed for 0.11.0
for older versions of neovim, i.e. not rendering on the initial load.

This is due to when the LSP window is created. On the `initial` run the
first call would use a non-final floating window. The final one gets
created later. Due to the debounce the next call with the correct
window was skipped.

To fix this add a check that the buffer is not empty before triggering
the update. This should work for all versions and skipping empty buffers
should always be valid.

Minor refactor: rename `BufferState` -> `Buffer`.

Author: MeanderingProgrammer

README.md

@@ -176,18 +176,18 @@ Some of the more useful fields are discussed further down.
 require('render-markdown').setup({
     -- Whether markdown should be rendered by default.
     enabled = true,
-    -- Vim modes that will show a rendered view of the markdown file, :h mode(), for
-    -- all enabled components. Individual components can be enabled for other modes.
-    -- Remaining modes will be unaffected by this plugin.
+    -- Vim modes that will show a rendered view of the markdown file, :h mode(), for all enabled
+    -- components. Individual components can be enabled for other modes. Remaining modes will be
+    -- unaffected by this plugin.
     render_modes = { 'n', 'c', 't' },
     -- Maximum file size (in MB) that this plugin will attempt to render.
     -- Any file larger than this will effectively be ignored.
     max_file_size = 10.0,
     -- Milliseconds that must pass before updating marks, updates occur.
     -- within the context of the visible window, not the entire buffer.
     debounce = 100,
-    -- Pre configured settings that will attempt to mimic various target
-    -- user experiences. Any user provided settings will take precedence.
+    -- Pre configured settings that will attempt to mimic various target user experiences.
+    -- Any user provided settings will take precedence.
     -- | obsidian | mimic Obsidian UI                                          |
     -- | lazy     | will attempt to stay up to date with LazyVim configuration |
     -- | none     | does nothing                                               |
@@ -221,7 +221,7 @@ require('render-markdown').setup({
         enabled = true,
         -- Which elements to always show, ignoring anti conceal behavior. Values can either be
         -- booleans to fix the behavior or string lists representing modes where anti conceal
-        -- behavior will be ignored. Possible keys are:
+        -- behavior will be ignored. Valid values are:
         --   head_icon, head_background, head_border, code_language, code_background, code_border
         --   dash, bullet, check_icon, check_scope, quote, table_border, callout, link, sign
         ignore = {
@@ -238,7 +238,7 @@ require('render-markdown').setup({
         highlight = 'Normal',
     },
     latex = {
-        -- Whether latex should be rendered, mainly used for health check
+        -- Turn on / off latex rendering.
         enabled = true,
         -- Additional modes to render latex.
         render_modes = false,
@@ -505,10 +505,10 @@ require('render-markdown').setup({
         -- Define custom checkbox states, more involved, not part of the markdown grammar.
         -- As a result this requires neovim >= 0.10.0 since it relies on 'inline' extmarks.
         -- The key is for healthcheck and to allow users to change its values, value type below.
-        -- | raw             | matched against the raw text of a 'shortcut_link'  |
-        -- | rendered        | replaces the 'raw' value when rendering            |
-        -- | highlight       | highlight for the 'rendered' icon                  |
-        -- | scope_highlight | highlight for item associated with custom checkbox |
+        -- | raw             | matched against the raw text of a 'shortcut_link'           |
+        -- | rendered        | replaces the 'raw' value when rendering                     |
+        -- | highlight       | highlight for the 'rendered' icon                           |
+        -- | scope_highlight | optional highlight for item associated with custom checkbox |
         custom = {
             todo = { raw = '[-]', rendered = '󰥔 ', highlight = 'RenderMarkdownTodo', scope_highlight = nil },
         },
@@ -1095,10 +1095,10 @@ require('render-markdown').setup({
         -- Define custom checkbox states, more involved, not part of the markdown grammar.
         -- As a result this requires neovim >= 0.10.0 since it relies on 'inline' extmarks.
         -- The key is for healthcheck and to allow users to change its values, value type below.
-        -- | raw             | matched against the raw text of a 'shortcut_link'  |
-        -- | rendered        | replaces the 'raw' value when rendering            |
-        -- | highlight       | highlight for the 'rendered' icon                  |
-        -- | scope_highlight | highlight for item associated with custom checkbox |
+        -- | raw             | matched against the raw text of a 'shortcut_link'           |
+        -- | rendered        | replaces the 'raw' value when rendering                     |
+        -- | highlight       | highlight for the 'rendered' icon                           |
+        -- | scope_highlight | optional highlight for item associated with custom checkbox |
         custom = {
             todo = { raw = '[-]', rendered = '󰥔 ', highlight = 'RenderMarkdownTodo', scope_highlight = nil },
         },

doc/render-markdown.txt

@@ -237,18 +237,18 @@ Default Configuration ~
     require('render-markdown').setup({
         -- Whether markdown should be rendered by default.
         enabled = true,
-        -- Vim modes that will show a rendered view of the markdown file, :h mode(), for
-        -- all enabled components. Individual components can be enabled for other modes.
-        -- Remaining modes will be unaffected by this plugin.
+        -- Vim modes that will show a rendered view of the markdown file, :h mode(), for all enabled
+        -- components. Individual components can be enabled for other modes. Remaining modes will be
+        -- unaffected by this plugin.
         render_modes = { 'n', 'c', 't' },
         -- Maximum file size (in MB) that this plugin will attempt to render.
         -- Any file larger than this will effectively be ignored.
         max_file_size = 10.0,
         -- Milliseconds that must pass before updating marks, updates occur.
         -- within the context of the visible window, not the entire buffer.
         debounce = 100,
-        -- Pre configured settings that will attempt to mimic various target
-        -- user experiences. Any user provided settings will take precedence.
+        -- Pre configured settings that will attempt to mimic various target user experiences.
+        -- Any user provided settings will take precedence.
         -- | obsidian | mimic Obsidian UI                                          |
         -- | lazy     | will attempt to stay up to date with LazyVim configuration |
         -- | none     | does nothing                                               |
@@ -282,7 +282,7 @@ Default Configuration ~
             enabled = true,
             -- Which elements to always show, ignoring anti conceal behavior. Values can either be
             -- booleans to fix the behavior or string lists representing modes where anti conceal
-            -- behavior will be ignored. Possible keys are:
+            -- behavior will be ignored. Valid values are:
             --   head_icon, head_background, head_border, code_language, code_background, code_border
             --   dash, bullet, check_icon, check_scope, quote, table_border, callout, link, sign
             ignore = {
@@ -299,7 +299,7 @@ Default Configuration ~
             highlight = 'Normal',
         },
         latex = {
-            -- Whether latex should be rendered, mainly used for health check
+            -- Turn on / off latex rendering.
             enabled = true,
             -- Additional modes to render latex.
             render_modes = false,
@@ -566,10 +566,10 @@ Default Configuration ~
             -- Define custom checkbox states, more involved, not part of the markdown grammar.
             -- As a result this requires neovim >= 0.10.0 since it relies on 'inline' extmarks.
             -- The key is for healthcheck and to allow users to change its values, value type below.
-            -- | raw             | matched against the raw text of a 'shortcut_link'  |
-            -- | rendered        | replaces the 'raw' value when rendering            |
-            -- | highlight       | highlight for the 'rendered' icon                  |
-            -- | scope_highlight | highlight for item associated with custom checkbox |
+            -- | raw             | matched against the raw text of a 'shortcut_link'           |
+            -- | rendered        | replaces the 'raw' value when rendering                     |
+            -- | highlight       | highlight for the 'rendered' icon                           |
+            -- | scope_highlight | optional highlight for item associated with custom checkbox |
             custom = {
                 todo = { raw = '[-]', rendered = '󰥔 ', highlight = 'RenderMarkdownTodo', scope_highlight = nil },
             },
@@ -1144,10 +1144,10 @@ Checkbox Configuration ~
             -- Define custom checkbox states, more involved, not part of the markdown grammar.
             -- As a result this requires neovim >= 0.10.0 since it relies on 'inline' extmarks.
             -- The key is for healthcheck and to allow users to change its values, value type below.
-            -- | raw             | matched against the raw text of a 'shortcut_link'  |
-            -- | rendered        | replaces the 'raw' value when rendering            |
-            -- | highlight       | highlight for the 'rendered' icon                  |
-            -- | scope_highlight | highlight for item associated with custom checkbox |
+            -- | raw             | matched against the raw text of a 'shortcut_link'           |
+            -- | rendered        | replaces the 'raw' value when rendering                     |
+            -- | highlight       | highlight for the 'rendered' icon                           |
+            -- | scope_highlight | optional highlight for item associated with custom checkbox |
             custom = {
                 todo = { raw = '[-]', rendered = '󰥔 ', highlight = 'RenderMarkdownTodo', scope_highlight = nil },
             },

lua/render-markdown/core/buffer.lua

@@ -0,0 +1,62 @@
+---@class render.md.Buffer
+---@field private buf integer
+---@field private empty boolean
+---@field private timer uv_timer_t
+---@field private running boolean
+---@field private marks? render.md.Extmark[]
+local Buffer = {}
+Buffer.__index = Buffer
+
+---@param buf integer
+---@return render.md.Buffer
+function Buffer.new(buf)
+    local self = setmetatable({}, Buffer)
+    self.buf = buf
+    self.empty = true
+    self.timer = (vim.uv or vim.loop).new_timer()
+    self.running = false
+    self.marks = nil
+    return self
+end
+
+---@return boolean
+function Buffer:is_empty()
+    if self.empty then
+        if vim.api.nvim_buf_line_count(self.buf) > 1 then
+            self.empty = false
+        else
+            local line = vim.api.nvim_buf_get_lines(self.buf, 0, -1, false)[1]
+            self.empty = line == nil or line == ''
+        end
+    end
+    return self.empty
+end
+
+---@param ms integer
+---@param callback fun()
+function Buffer:debounce(ms, callback)
+    self.timer:start(ms, 0, function()
+        self.running = false
+    end)
+    if not self.running then
+        self.running = true
+        vim.schedule(callback)
+    end
+end
+
+---@return boolean
+function Buffer:has_marks()
+    return self.marks ~= nil
+end
+
+---@return render.md.Extmark[]
+function Buffer:get_marks()
+    return self.marks or {}
+end
+
+---@param marks? render.md.Extmark[]
+function Buffer:set_marks(marks)
+    self.marks = marks
+end
+
+return Buffer

lua/render-markdown/core/buffer_state.lua

@@ -1,4 +1,4 @@
-local BufferState = require('render-markdown.core.buffer_state')
+local Buffer = require('render-markdown.core.buffer')
 local Context = require('render-markdown.core.context')
 local Extmark = require('render-markdown.core.extmark')
 local Iter = require('render-markdown.lib.iter')
@@ -15,20 +15,20 @@ local builtin_handlers = {
 }
 
 ---@class render.md.cache.Ui
----@field states table<integer, render.md.BufferState>
+---@field states table<integer, render.md.Buffer>
 local Cache = {
     states = {},
 }
 
 ---@param buf integer
----@return render.md.BufferState
+---@return render.md.Buffer
 function Cache.get(buf)
-    local buffer_state = Cache.states[buf]
-    if buffer_state == nil then
-        buffer_state = BufferState.new()
-        Cache.states[buf] = buffer_state
+    local buffer = Cache.states[buf]
+    if buffer == nil then
+        buffer = Buffer.new(buf)
+        Cache.states[buf] = buffer
     end
-    return buffer_state
+    return buffer
 end
 
 ---@class render.md.Ui
@@ -37,8 +37,8 @@ local M = {}
 M.ns = vim.api.nvim_create_namespace('render-markdown.nvim')
 
 function M.invalidate_cache()
-    for buf, buffer_state in pairs(Cache.states) do
-        M.clear(buf, buffer_state)
+    for buf, buffer in pairs(Cache.states) do
+        M.clear(buf, buffer)
     end
     Cache.states = {}
 end
@@ -47,13 +47,13 @@ end
 ---@param win integer
 ---@return integer, render.md.Mark[]
 function M.get_row_marks(buf, win)
-    local config, buffer_state = state.get(buf), Cache.get(buf)
+    local config, buffer = state.get(buf), Cache.get(buf)
     local mode, row = util.mode(), util.row(buf, win)
     local hidden = config:hidden(mode, row)
     assert(row ~= nil and hidden ~= nil, 'Row & range must be known to get marks')
 
     local marks = {}
-    for _, extmark in ipairs(buffer_state:get_marks()) do
+    for _, extmark in ipairs(buffer:get_marks()) do
         if extmark:inside(hidden) then
             table.insert(marks, extmark:get())
         end
@@ -63,10 +63,10 @@ end
 
 ---@private
 ---@param buf integer
----@param buffer_state render.md.BufferState
-function M.clear(buf, buffer_state)
+---@param buffer render.md.Buffer
+function M.clear(buf, buffer)
     vim.api.nvim_buf_clear_namespace(buf, M.ns, 0, -1)
-    buffer_state:set_marks(nil)
+    buffer:set_marks(nil)
 end
 
 ---Used directly by fzf-lua: https://github.com/ibhagwan/fzf-lua/blob/main/lua/fzf-lua/previewer/builtin.lua
@@ -76,12 +76,15 @@ end
 ---@param change boolean
 function M.update(buf, win, event, change)
     log.buf('info', 'update', buf, string.format('event %s', event), string.format('change %s', change))
-    if not util.valid(buf, win) then
+    if util.invalid(buf, win) then
         return
     end
 
     local parse = M.parse(buf, win, change)
-    local config, buffer_state = state.get(buf), Cache.get(buf)
+    local config, buffer = state.get(buf), Cache.get(buf)
+    if buffer:is_empty() then
+        return
+    end
 
     local update = function()
         M.run_update(buf, win, change)
@@ -91,7 +94,7 @@ function M.update(buf, win, event, change)
     end
 
     if parse and config.debounce > 0 then
-        buffer_state:debounce(config.debounce, update)
+        buffer:debounce(config.debounce, update)
     else
         vim.schedule(update)
     end
@@ -112,12 +115,12 @@ end
 ---@param win integer
 ---@param change boolean
 function M.run_update(buf, win, change)
-    if not util.valid(buf, win) then
+    if util.invalid(buf, win) then
         return
     end
 
     local parse = M.parse(buf, win, change)
-    local config, buffer_state = state.get(buf), Cache.get(buf)
+    local config, buffer = state.get(buf), Cache.get(buf)
     local mode, row = util.mode(), util.row(buf, win)
     local next_state = M.next_state(config, win, mode)
 
@@ -129,17 +132,17 @@ function M.run_update(buf, win, change)
     end
 
     if next_state == 'rendered' then
-        if not buffer_state:has_marks() or parse then
-            M.clear(buf, buffer_state)
-            buffer_state:set_marks(M.parse_buffer({
+        if not buffer:has_marks() or parse then
+            M.clear(buf, buffer)
+            buffer:set_marks(M.parse_buffer({
                 buf = buf,
                 win = win,
                 mode = mode,
                 top_level_mode = util.in_modes(config.render_modes, mode),
             }))
         end
         local hidden = config:hidden(mode, row)
-        local extmarks = buffer_state:get_marks()
+        local extmarks = buffer:get_marks()
         for _, extmark in ipairs(extmarks) do
             if extmark:get().conceal and extmark:inside(hidden) then
                 extmark:hide(M.ns, buf)
@@ -149,7 +152,7 @@ function M.run_update(buf, win, change)
         end
         state.on.render({ buf = buf })
     else
-        M.clear(buf, buffer_state)
+        M.clear(buf, buffer)
         state.on.clear({ buf = buf })
     end
 end