Add a query linter module

lua/nvim-treesitter-playground.lua

@@ -1,3 +1,4 @@
+local parsers = require 'nvim-treesitter.parsers'
 local M = {}
 
 vim.cmd [[
@@ -10,7 +11,13 @@ function M.init()
       module_path = "nvim-treesitter-playground.internal",
       updatetime = 25,
       persist_queries = false
-    }
+    },
+    query_linter = {
+      module_path = "nvim-treesitter-playground.query_linter",
+      is_supported = function(lang)
+        return lang == 'query' and parsers.has_parser('query')
+      end,
+    },
   }
 end
 

lua/nvim-treesitter-playground/query_linter.lua

@@ -0,0 +1,97 @@
+local api = vim.api
+local queries = require "nvim-treesitter.query"
+local ts_utils = require "nvim-treesitter.ts_utils"
+local utils = require "nvim-treesitter.utils"
+
+local hl_namespace = api.nvim_create_namespace("nvim-playground-lints")
+local ERROR_HL = "TSQueryLinterError"
+
+local M = {}
+
+M.lints = {}
+M.use_virtual_text = true
+
+local function lint_node(node, buf, message_prefix)
+    ts_utils.highlight_node(node, buf, hl_namespace, ERROR_HL)
+    local error_text = message_prefix..': '..table.concat(ts_utils.get_node_text(node, buf), ' ')
+    local error_range = {node:range()}
+    if M.use_virtual_text then
+      api.nvim_buf_set_virtual_text(buf, hl_namespace, error_range[1], {{error_text, ERROR_HL}}, {})
+    end
+    table.insert(M.lints[buf], { type = message_prefix, range = error_range, message = error_text })
+end
+
+local function table_contains(predicate, table)
+  for _, elt in pairs(table) do
+    if predicate(elt) then
+      return true
+    end
+  end
+  return false
+end
+
+function M.lint(buf)
+  buf = buf or api.nvim_get_current_buf()
+  M.clear_virtual_text(buf)
+  M.lints[buf] = {}
+
+  local filename = api.nvim_buf_get_name(buf)
+  local ok, query_lang = pcall(vim.fn.fnamemodify, filename, ":p:h:t")
+  local query_lang = ok and query_lang
+  local ok, parser_info = pcall(vim.treesitter.inspect_language, query_lang)
+  local parser_info = ok and parser_info
+
+  local matches = queries.get_matches(buf, "query-linter-queries")
+
+  for _, m in pairs(matches) do
+    local error_node = utils.get_at_path(m, "error.node")
+
+    if error_node then
+      lint_node(error_node, buf, "Syntax Error")
+    end
+
+    if parser_info and parser_info.symbols then
+
+      --for _, p in pairs(parser_info.symbols) do
+        --D(p[1])
+      --end
+
+      local named_node = utils.get_at_path(m, "named_node.node")
+      if named_node then
+        local node_type = ts_utils.get_node_text(named_node)[1]
+        local found = node_type == '_' or table_contains(function(t) return node_type == t[1]..'' end, parser_info.symbols)
+        if not found then
+          lint_node(named_node, buf, "Invalid Node Type")
+        end
+      end
+    end
+
+  end
+end
+
+function M.clear_virtual_text(buf)
+  api.nvim_buf_clear_namespace(buf, hl_namespace, 0, -1)
+end
+
+function M.attach(buf, _)
+  M.lints[buf] = {}
+
+  vim.cmd(string.format("augroup TreesitterPlaygroundLint_%d", buf))
+  vim.cmd "au!"
+  vim.cmd(
+    string.format(
+      [[autocmd CursorHold <buffer=%d> lua require'nvim-treesitter-playground.query_linter'.lint(%d)]],
+      buf,
+      buf
+    )
+  )
+  vim.cmd "augroup END"
+end
+
+function M.detach(buf)
+  M.lints[buf] = nil
+  M.clear_virtual_text(buf)
+  vim.cmd(string.format("autocmd! TreesitterPlaygroundLint_%d CursorHold", buf))
+end
+
+return M

plugin/nvim-treesitter-playground.vim

@@ -3,5 +3,6 @@ require "nvim-treesitter-playground".init()
 EOF
 
 highlight default link TSPlaygroundFocus Visual
+highlight default link TSQueryLinterError Error
 
 command! TSPlaygroundToggle lua require "nvim-treesitter-playground.internal".toggle()

queries/query/query-linter-queries.scm

@@ -0,0 +1,4 @@
+(program (named_node) @toplevel-query)
+(named_node
+   name: (identifier) @named_node)
+(ERROR) @error