Merge pull request #330 from steelsojka/fix-do-not-reattach

fix(modules): do not reattach if already attached

10 files changed, 76 insertions, 42 deletions

diff --git a/lua/nvim-treesitter/caching.lua b/lua/nvim-treesitter/caching.lua
new file mode 100644
index 000000000..bfda39622
--- /dev/null
+++ b/lua/nvim-treesitter/caching.lua
@@ -0,0 +1,48 @@
+local api = vim.api
+
+local M = {}
+
+--- Creates a cache table for buffers keyed by a type name.
+--- Cache entries attach to the buffer and cleanup entries
+--- as buffers are detached.
+function M.create_buffer_cache()
+  local cache = {}
+
+  local items = setmetatable({}, {
+    __index = function(tbl, key)
+      rawset(tbl, key, {})
+      return rawget(tbl, key)
+    end
+  })
+
+  function cache.set(type_name, bufnr, value)
+    if not cache.has(type_name, bufnr) then
+      -- Clean up the cache if the buffer is detached
+      -- to avoid memory leaks
+      api.nvim_buf_attach(bufnr, false, {
+        on_detach = function()
+          cache.remove(type_name, bufnr)
+          return true
+        end
+      })
+    end
+
+    items[type_name][bufnr] = value
+  end
+
+  function cache.get(type_name, bufnr)
+    return items[type_name][bufnr]
+  end
+
+  function cache.has(type_name, bufnr)
+    return cache.get(type_name, bufnr) ~= nil
+  end
+
+  function cache.remove(type_name, bufnr)
+    items[type_name][bufnr] = nil
+  end
+
+  return cache
+end
+
+return M
diff --git a/lua/nvim-treesitter/configs.lua b/lua/nvim-treesitter/configs.lua
index ba4ae3f8d..51d982c79 100644
--- a/lua/nvim-treesitter/configs.lua
+++ b/lua/nvim-treesitter/configs.lua
@@ -3,6 +3,7 @@ local api = vim.api
 local queries = require'nvim-treesitter.query'
 local parsers = require'nvim-treesitter.parsers'
 local utils = require'nvim-treesitter.utils'
+local caching = require'nvim-treesitter.caching'
 
 local M = {}
 
@@ -109,6 +110,8 @@ local builtin_modules = {
   }
 }
 
+local attached_buffers_by_module = caching.create_buffer_cache()
+
 -- Resolves a module by requiring the `module_path` or using the module definition.
 local function resolve_module(mod_name)
   local config_mod = M.get_module(mod_name)
@@ -367,8 +370,13 @@ end
 -- @param lang the language of the buffer
 function M.attach_module(mod_name, bufnr, lang)
   local resolved_mod = resolve_module(mod_name)
+  local bufnr = bufnr or api.nvim_get_current_buf()
 
-  if resolved_mod and parsers.has_parser(lang) then
+  if resolved_mod
+    and parsers.has_parser(lang)
+    and not attached_buffers_by_module.has(mod_name, bufnr)
+  then
+    attached_buffers_by_module.set(mod_name, bufnr, true)
     resolved_mod.attach(bufnr, lang)
   end
 end
@@ -378,8 +386,10 @@ end
 -- @param bufnr the bufnr
 function M.detach_module(mod_name, bufnr)
   local resolved_mod = resolve_module(mod_name)
+  local bufnr = bufnr or api.nvim_get_current_buf()
 
   if resolved_mod then
+    attached_buffers_by_module.remove(mod_name, bufnr)
     resolved_mod.detach(bufnr)
   end
 end
diff --git a/lua/nvim-treesitter/highlight.lua b/lua/nvim-treesitter/highlight.lua
index 1fbc6621d..a9549fc06 100644
--- a/lua/nvim-treesitter/highlight.lua
+++ b/lua/nvim-treesitter/highlight.lua
@@ -69,7 +69,6 @@ hlmap["text.literal"] = "TSLiteral"
 hlmap["text.uri"] = "TSURI"
 
 function M.attach(bufnr, lang)
-  local bufnr = bufnr or api.nvim_get_current_buf()
   local lang = lang or parsers.get_buf_lang(bufnr)
   local config = configs.get_module('highlight')
 
@@ -84,12 +83,11 @@ function M.attach(bufnr, lang)
 end
 
 function M.detach(bufnr)
-  local buf = bufnr or api.nvim_get_current_buf()
-  if M.highlighters[buf] then
-    M.highlighters[buf]:set_query("")
-    M.highlighters[buf] = nil
+  if M.highlighters[bufnr] then
+    M.highlighters[bufnr]:set_query("")
+    M.highlighters[bufnr] = nil
   end
-  api.nvim_buf_set_option(buf, 'syntax', 'on')
+  api.nvim_buf_set_option(bufnr, 'syntax', 'on')
 end
 
 return M
diff --git a/