fix(treesitter): offset directive associates range with capture (#18276)

Previously the `offset!` directive populated the metadata in such a way
that the new range could be attributed to a specific capture. #14046
made it so the directive simply stored just the new range in the
metadata and information about what capture the range is based from is
lost.

This change reverts that whilst also correcting the docs.

runtime/lua/vim/treesitter/languagetree.lua

@@ -295,6 +295,14 @@ function LanguageTree:included_regions()
   return self._regions
 end
 
+---@private
+local function get_node_range(node, id, metadata)
+  if metadata[id] and metadata[id].range then
+    return metadata[id].range
+  end
+  return { node:range() }
+end
+
 --- Gets language injection points by language.
 ---
 --- This is where most of the injection processing occurs.
@@ -327,10 +335,10 @@ function LanguageTree:_get_injections()
 
         -- Allow for captured nodes to be used
         if type(content) == 'number' then
-          content = { match[content] }
+          content = { match[content]:range() }
         end
 
-        if content then
+        if type(content) == 'table' and #content >= 4 then
           vim.list_extend(ranges, content)
         end
       end
@@ -351,7 +359,7 @@ function LanguageTree:_get_injections()
         elseif name == 'combined' then
           combined = true
         elseif name == 'content' and #ranges == 0 then
-          table.insert(ranges, node)
+          table.insert(ranges, get_node_range(node, id, metadata))
           -- Ignore any tags that start with "_"
           -- Allows for other tags to be used in matches
         elseif string.sub(name, 1, 1) ~= '_' then
@@ -360,7 +368,7 @@ function LanguageTree:_get_injections()
           end
 
           if #ranges == 0 then
-            table.insert(ranges, node)
+            table.insert(ranges, get_node_range(node, id, metadata))
           end
         end
       end
@@ -397,7 +405,10 @@ function LanguageTree:_get_injections()
 
       for _, entry in pairs(patterns) do
         if entry.combined then
-          table.insert(result[lang], vim.tbl_flatten(entry.regions))
+          local regions = vim.tbl_map(function(e)
+            return vim.tbl_flatten(e)
+          end, entry.regions)
+          table.insert(result[lang], regions)
         else
           for _, ranges in ipairs(entry.regions) do
             table.insert(result[lang], ranges)

runtime/lua/vim/treesitter/query.lua

@@ -313,20 +313,22 @@ local directive_handlers = {
   ['set!'] = function(_, _, _, pred, metadata)
     if #pred == 4 then
       -- (#set! @capture "key" "value")
-      local capture = pred[2]
-      if not metadata[capture] then
-        metadata[capture] = {}
+      local _, capture_id, key, value = unpack(pred)
+      if not metadata[capture_id] then
+        metadata[capture_id] = {}
       end
-      metadata[capture][pred[3]] = pred[4]
+      metadata[capture_id][key] = value
     else
+      local _, key, value = unpack(pred)
       -- (#set! "key" "value")
-      metadata[pred[2]] = pred[3]
+      metadata[key] = value
     end
   end,
   -- Shifts the range of a node.
   -- Example: (#offset! @_node 0 1 0 -1)
   ['offset!'] = function(match, _, _, pred, metadata)
-    local offset_node = match[pred[2]]
+    local capture_id = pred[2]
+    local offset_node = match[capture_id]
     local range = { offset_node:range() }
     local start_row_offset = pred[3] or 0
     local start_col_offset = pred[4] or 0
@@ -340,7 +342,10 @@ local directive_handlers = {
 
     -- If this produces an invalid range, we just skip it.
     if range[1] < range[3] or (range[1] == range[3] and range[2] <= range[4]) then
-      metadata.content = { range }
+      if not metadata[capture_id] then
+        metadata[capture_id] = {}
+      end
+      metadata[capture_id].range = range
     end
   end,
 }
@@ -360,9 +365,14 @@ end
 
 --- Adds a new directive to be used in queries
 ---
+--- Handlers can set match level data by setting directly on the
+--- metadata object `metadata.key = value`, additionally, handlers
+--- can set node level data by using the capture id on the
+--- metadata table `metadata[capture_id].key = value`
+---
 ---@param name the name of the directive, without leading #
 ---@param handler the handler function to be used
----      signature will be (match, pattern, bufnr, predicate)
+---      signature will be (match, pattern, bufnr, predicate, metadata)
 function M.add_directive(name, handler, force)
   if directive_handlers[name] and not force then
     error(string.format('Overriding %s', name))
@@ -371,6 +381,7 @@ function M.add_directive(name, handler, force)
   directive_handlers[name] = handler
 end
 
+--- Lists the currently available directives to use in queries.
 ---@return The list of supported directives.
 function M.list_directives()
   return vim.tbl_keys(directive_handlers)