feat: experimental support for navigating to symbol names (#279)

Using the treesitter backend, we can use the same "selectionRange" logic
that LSP symbol sources use to provide more detailed information about
where the name of the symbol is. We already use the LSP information to
change how we navigate the cursor to symbols, so once we parse this
information from treesitter it will automatically get used.

I'm putting this behind an experimental config option for now so we can
test it out for a while before making a sudden change to the behavior.

lua/aerial/backends/treesitter/extensions.lua

@@ -1,6 +1,8 @@
+local config = require("aerial.config")
 -- This file is used by the markdown backend as well.
 -- We pcall(require) so it doesn't error when nvim-treesitter isn't installed.
 local _, utils = pcall(require, "nvim-treesitter.utils")
+local helpers = require("aerial.backends.treesitter.helpers")
 local M = {}
 
 local get_node_text
@@ -178,6 +180,10 @@ M.help = {
         node = node:prev_sibling()
         item.lnum = row + 1
         item.col = col
+        if item.selection_range then
+          item.selection_range.lnum = row + 1
+          item.selection_range.col = col
+        end
       end
       item.name = table.concat(pieces, " ")
     end
@@ -278,6 +284,9 @@ local function c_postprocess(bufnr, item, match)
       end
     end
     item.name = get_node_text(root, bufnr) or "<parse error>"
+    if config.treesitter.experimental_selection_range and not item.selection_range then
+      item.selection_range = helpers.range_from_nodes(root, root)
+    end
   end
 end
 

lua/aerial/backends/treesitter/helpers.lua

@@ -0,0 +1,17 @@
+local M = {}
+
+---@param start_node TSNode
+---@param end_node TSNode
+---@return aerial.Range
+M.range_from_nodes = function(start_node, end_node)
+  local row, col = start_node:start()
+  local end_row, end_col = end_node:end_()
+  return {
+    lnum = row + 1,
+    end_lnum = end_row + 1,
+    col = col,
+    end_col = end_col,
+  }
+end
+
+return M

lua/aerial/backends/treesitter/init.lua

@@ -1,5 +1,6 @@
 local backends = require("aerial.backends")
 local config = require("aerial.config")
+local helpers = require("aerial.backends.treesitter.helpers")
 local util = require("aerial.backends.util")
 
 ---@type aerial.Backend
@@ -60,12 +61,14 @@ M.fetch_symbols_sync = function(bufnr)
     )
     return
   end
+  local use_selection_range = config.treesitter.experimental_selection_range
   -- This will track a loose hierarchy of recent node+items.
   -- It is used to determine node parents for the tree structure.
   local stack = {}
   local ext = extensions[lang]
   for match in query.iter_group_results(bufnr, "aerial", syntax_tree:root(), lang) do
     local name_match = match.name or {}
+    local selection_match = match.selection or {}
     local type_node = (match.type or {}).node
     -- The location capture groups are optional. We default to the
     -- location of the @type capture
@@ -89,11 +92,17 @@ M.fetch_symbols_sync = function(bufnr)
       )
       break
     end
-    local row, col = start_node:start()
-    local end_row, end_col = end_node:end_()
+    local range = helpers.range_from_nodes(start_node, end_node)
+    local selection_range
+    if selection_match.node then
+      selection_range = helpers.range_from_nodes(selection_match.node, selection_match.node)
+    end
     local name
     if name_match.node then
       name = get_node_text(name_match.node, bufnr, name_match) or "<parse error>"
+      if not selection_range then
+        selection_range = helpers.range_from_nodes(name_match.node, name_match.node)
+      end
     else
       name = "<Anonymous>"
     end
@@ -103,11 +112,13 @@ M.fetch_symbols_sync = function(bufnr)
       name = name,
       level = level,
       parent = parent_item,
-      lnum = row + 1,
-      end_lnum = end_row + 1,
-      col = col,
-      end_col = end_col,
     }
+    if use_selection_range then
+      item.selection_range = selection_range
+    end
+    for k, v in pairs(range) do
+      item[k] = v
+    end
     if ext.postprocess(bufnr, item, match) == false or not include_kind[item.kind] then
       goto continue
     end

lua/aerial/config.lua

@@ -335,6 +335,10 @@ local default_options = {
   treesitter = {
     -- How long to wait (in ms) after a buffer change before updating
     update_delay = 300,
+    -- Experimental feature to navigate to symbol names instead of the declaration
+    -- See https://github.com/stevearc/aerial.nvim/issues/279
+    -- If no bugs are reported for a time this will become the default
+    experimental_selection_range = false,
   },
 
   markdown = {

queries/lua/aerial.scm

@@ -32,7 +32,7 @@
     (string)? @name
     (function_definition) @type)
   (#set! "kind" "Function")
-) @start
+) @start @selection
 
 (function_call
   name: (dot_index_expression
@@ -43,4 +43,4 @@
     (string)? @name
     (function_definition) @type)
   (#set! "kind" "Function")
-) @start
+) @start @selection

queries/ruby/aerial.scm

@@ -40,4 +40,4 @@
      (call) @name
     ])?
   (#set! "kind" "Method")
-) @type
+) @type @selection

queries/tsx/aerial.scm

@@ -48,7 +48,7 @@
     (string
       (string_fragment) @name @string))?
   (#set! "kind" "Function")
-  ) @type
+  ) @type @selection
 
 ; test.skip("this test")
 (call_expression
@@ -60,7 +60,7 @@
     (string
       (string_fragment) @name @string))?
   (#set! "kind" "Function")
-  ) @type
+  ) @type @selection
 
 ; describe.each([])("Test suite")
 (call_expression
@@ -74,4 +74,4 @@
     (string
       (string_fragment) @name @string))?
   (#set! "kind" "Function")
-  ) @type
+  ) @type @selection

queries/typescript/aerial.scm

@@ -48,7 +48,7 @@
     (string
       (string_fragment) @name @string))?
   (#set! "kind" "Function")
-  ) @type
+  ) @type @selection
 
 ; test.skip("this test")
 (call_expression
@@ -60,7 +60,7 @@
     (string
       (string_fragment) @name @string))?
   (#set! "kind" "Function")
-  ) @type
+  ) @type @selection
 
 ; describe.each([])("Test suite")
 (call_expression
@@ -74,4 +74,4 @@
     (string
       (string_fragment) @name @string))?
   (#set! "kind" "Function")
-  ) @type
+  ) @type @selection