fix(markdown): Ensure content is followed by '#'

Before this commit, empty headings are taken into account:

   # a normal heading

   below is not a good heading:

   #

   below is also not a good heading:

   ##

   These should not be listed in the outline.

README.md

@@ -47,6 +47,8 @@ I do not merge PRs from the original repo that I don't personally need.
 - Open handler triggering multiple times ends up in messy state with errors
   simrat39/symbols-outline.nvim#235
 - Fixed `_highlight_current_item` function checking provider on outline window
+- Fixed behaviour of empty markdown headings `^(#+)(%s+)$` being listed in the
+outline.
 
 ## 🛑 Breaking changes
 

lua/symbols-outline/markdown.lua

@@ -15,11 +15,14 @@ function M.handle_markdown()
     if string.find(value, '^```') then
       is_inside_code_block = not is_inside_code_block
     end
+    if is_inside_code_block then
+      goto nextline
+    end
 
     local next_value = lines[line+1]
     local is_emtpy_line = #value:gsub("^%s*(.-)%s*$", "%1") == 0
 
-    local header, title = string.match(value, '^(#+)%s+(.*)$')
+    local header, title = string.match(value, '^(#+)%s+(.+)$')
     if not header and next_value and not is_emtpy_line then
       if string.match(next_value, '^=+%s*$') then
         header = '#'
@@ -29,44 +32,50 @@ function M.handle_markdown()
         title = value
       end
     end
-
+    if not header or not title then
-    if header and not is_inside_code_block then
+      goto nextline
-      local depth = #header + 1
-
-      local parent
-      for i = depth - 1, 1, -1 do
-        if level_symbols[i] ~= nil then
-          parent = level_symbols[i].children
-          break
-        end
-      end
-
-      for i = depth, max_level do
-        if level_symbols[i] ~= nil then
-          level_symbols[i].selectionRange['end'].line = line - 1
-          level_symbols[i].range['end'].line = line - 1
-          level_symbols[i] = nil
-        end
-      end
-      max_level = depth
-
-      local entry = {
-        kind = 13,
-        name = title,
-        selectionRange = {
-          start = { character = 1, line = line - 1 },
-          ['end'] = { character = 1, line = line - 1 },
-        },
-        range = {
-          start = { character = 1, line = line - 1 },
-          ['end'] = { character = 1, line = line - 1 },
-        },
-        children = {},
-      }
-
-      parent[#parent + 1] = entry
-      level_symbols[depth] = entry
     end
+    -- TODO: This is not needed and it works?
+    -- if #header > 6 then
+    --   goto nextline
+    -- end
+
+    local depth = #header + 1
+
+    local parent
+    for i = depth - 1, 1, -1 do
+      if level_symbols[i] ~= nil then
+        parent = level_symbols[i].children
+        break
+      end
+    end
+
+    for i = depth, max_level do
+      if level_symbols[i] ~= nil then
+        level_symbols[i].selectionRange['end'].line = line - 1
+        level_symbols[i].range['end'].line = line - 1
+        level_symbols[i] = nil
+      end
+    end
+    max_level = depth
+
+    local entry = {
+      kind = 13,
+      name = title,
+      selectionRange = {
+        start = { character = 1, line = line - 1 },
+        ['end'] = { character = 1, line = line - 1 },
+      },
+      range = {
+        start = { character = 1, line = line - 1 },
+        ['end'] = { character = 1, line = line - 1 },
+      },
+      children = {},
+    }
+
+    parent[#parent + 1] = entry
+    level_symbols[depth] = entry
+    ::nextline::
   end
 
   for i = 2, max_level do