feat(nvim): handle prittier ignoring alerts/callouts

Author: scottames

home/private_dot_config/nvim/lua/plugins/lsp.lua

@@ -27,7 +27,7 @@ return {
         hcl = { "terragrunt_hclfmt" },
         json = { "prettierd", "prettier", stop_after_first = true },
         justfile = { "just" },
-        markdown = { "prettierd", "markdownlint", "markdown-toc" },
+        markdown = { "protect_gh_alerts", "prettierd", "markdownlint", "markdown-toc" },
         ["markdown.mdx"] = { "prettierd", "prettier", stop_after_first = true },
         lua = { "stylua" },
         packer = { "packer_fmt" },
@@ -41,6 +41,19 @@ return {
         zsh = { "beautysh" },
       },
       formatters = {
+        -- Protect GitHub-style alert blocks from Prettier reformatting
+        -- https://github.com/prettier/prettier/issues/15479
+        protect_gh_alerts = {
+          meta = {
+            url = "https://github.com/prettier/prettier/issues/15479",
+            description = "Wrap GitHub-style alert blocks in prettier-ignore comments",
+          },
+          command = "lua",
+          stdin = true,
+          args = function()
+            return { vim.fn.stdpath("config") .. "/lua/util/protect_gh_alerts.lua" }
+          end,
+        },
         beautysh = {
           prepend_args = { "--indent-size", "2" },
         },

home/private_dot_config/nvim/lua/util/protect_gh_alerts.lua

@@ -0,0 +1,153 @@
+#!/usr/bin/env lua
+-- protect_gh_alerts.lua
+--
+-- Protect GitHub-style alert blocks from Prettier reformatting by wrapping
+-- them in <!-- prettier-ignore-start --> / <!-- prettier-ignore-end --> comments.
+--
+-- This script is designed to be used as a stdin/stdout formatter with conform.nvim.
+--
+-- GitHub Alert Syntax:
+--   > [!NOTE]
+--   > Content here
+--
+-- Supported alert types: NOTE, TIP, IMPORTANT, WARNING, CAUTION
+--
+-- Reference: https://github.com/prettier/prettier/issues/15479
+
+-- Configuration
+local MAX_LINES = 10000
+local ALERT_TYPES = { "NOTE", "TIP", "IMPORTANT", "WARNING", "CAUTION" }
+
+-- Read all input
+local content = io.read("*all")
+if not content or content == "" then
+  return
+end
+
+local lines = {}
+for line in content:gmatch("([^\n]*)\n?") do
+  table.insert(lines, line)
+end
+
+-- Remove trailing empty string from gmatch if present
+if #lines > 0 and lines[#lines] == "" then
+  table.remove(lines)
+end
+
+-- Performance check
+if #lines > MAX_LINES then
+  io.stderr:write(
+    string.format("[protect_gh_alerts] Skipping large file (%d lines > %d threshold)\n", #lines, MAX_LINES)
+  )
+  io.write(content)
+  return
+end
+
+-- Helper: check if line is alert start
+local function is_alert_start(line)
+  for _, alert_type in ipairs(ALERT_TYPES) do
+    if line:match("^%s*>%s*%[!" .. alert_type .. "%]") then
+      return true, alert_type
+    end
+  end
+  return false, nil
+end
+
+-- Helper: check if already protected (look back up to 2 lines for prettier-ignore-start or prettier-ignore)
+local function is_protected(output)
+  local check_count = math.min(2, #output)
+  for offset = 0, check_count - 1 do
+    local idx = #output - offset
+    if idx > 0 then
+      local prev_line = output[idx]
+      -- Match both prettier-ignore-start and prettier-ignore (for backwards compatibility)
+      if
+        prev_line:match("prettier%-ignore%-start")
+        or prev_line:match("prettier%-ignore[^%-]")
+        or prev_line:match("prettier%-ignore$")
+      then
+        return true
+      end
+      -- Stop at non-empty, non-whitespace line that isn't a blank line
+      if prev_line:match("%S") and not prev_line:match("^%s*$") then
+        break
+      end
+    end
+  end
+  return false
+end
+
+-- Process lines
+local output = {}
+local i = 1
+local protected_count = 0
+
+while i <= #lines do
+  local line = lines[i]
+  local is_alert, alert_type = is_alert_start(line)
+
+  if is_alert then
+    -- Check if already protected
+    if is_protected(output) then
+      -- Already protected, just copy lines
+      table.insert(output, line)
+      i = i + 1
+
+      -- Copy remaining alert lines
+      while i <= #lines and lines[i]:match("^%s*>") do
+        table.insert(output, lines[i])
+        i = i + 1
+      end
+    else
+      -- Protect this alert block
+      local indent = line:match("^(%s*)") or ""
+
+      -- Insert ignore-start comment
+      table.insert(output, indent .. "<!-- prettier-ignore-start -->")
+
+      -- Copy alert start
+      table.insert(output, line)
+      local alert_start_line = i
+      i = i + 1
+
+      -- Copy all consecutive blockquote lines (including empty >)
+      local last_alert_line = alert_start_line
+      while i <= #lines and lines[i]:match("^%s*>") do
+        table.insert(output, lines[i])
+        last_alert_line = i
+        i = i + 1
+      end
+
+      -- Insert end comment after the alert block
+      table.insert(output, indent .. "<!-- prettier-ignore-end -->")
+
+      -- Log protection
+      protected_count = protected_count + 1
+      io.stderr:write(
+        string.format(
+          "[protect_gh_alerts] Protected %s alert at line %d-%d\n",
+          alert_type,
+          alert_start_line,
+          last_alert_line
+        )
+      )
+    end
+  else
+    -- Regular line, just copy
+    table.insert(output, line)
+    i = i + 1
+  end
+end
+
+-- Write output
+io.write(table.concat(output, "\n"))
+
+-- Ensure file ends with newline
+if #output > 0 then
+  io.write("\n")
+end
+
+-- Summary log
+if protected_count > 0 then
+  io.stderr:write(string.format("[protect_gh_alerts] Protected %d alert block(s)\n", protected_count))
+end