Merge pull request #27295 from wookayin/feat/inspecttree

feat(treesitter): use 0-based indexing to show ranges in `:InspectTree`

3 files changed, 126 insertions, 14 deletions

diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index e83fc25f88..c1fc04d9cf 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -224,6 +224,8 @@ The following new APIs and features were added.
   • |vim.treesitter.query.edit()| allows live editing of treesitter
     queries.
   • Improved error messages for query parsing.
+  • `:InspectTree` (|vim.treesitter.inspect_tree()|) shows node ranges in
+    0-based indexing instead of 1-based indexing.
 
 • |vim.ui.open()| opens URIs using the system default handler (macOS `open`,
   Windows `explorer`, Linux `xdg-open`, etc.)
diff --git a/runtime/lua/vim/treesitter/dev.lua b/runtime/lua/vim/treesitter/dev.lua
index 1385642acd..e1f93a654b 100644
--- a/runtime/lua/vim/treesitter/dev.lua
+++ b/runtime/lua/vim/treesitter/dev.lua
@@ -3,16 +3,20 @@ local api = vim.api
 ---@class TSDevModule
 local M = {}
 
+---@private
 ---@class TSTreeView
 ---@field ns integer API namespace
----@field opts table Options table with the following keys:
----                  - anon (boolean): If true, display anonymous nodes
----                  - lang (boolean): If true, display the language alongside each node
----                  - indent (number): Number of spaces to indent nested lines. Default is 2.
+---@field opts TSTreeViewOpts
 ---@field nodes TSP.Node[]
 ---@field named TSP.Node[]
 local TSTreeView = {}
 
+---@private
+---@class TSTreeViewOpts
+---@field anon boolean If true, display anonymous nodes.
+---@field lang boolean If true, display the language alongside each node.
+---@field indent number Number of spaces to indent nested lines.
+
 ---@class TSP.Node
 ---@field node TSNode Treesitter node
 ---@field field string? Node field
@@ -115,6 +119,7 @@ function TSTreeView:new(bufnr, lang)
     ns = api.nvim_create_namespace('treesitter/dev-inspect'),
     nodes = nodes,
     named = named,
+    ---@type TSTreeViewOpts
     opts = {
       anon = false,
       lang = false,
@@ -129,16 +134,12 @@ end
 
 local decor_ns = api.nvim_create_namespace('ts.dev')
 
----@param lnum integer
----@param col integer
----@param end_lnum integer
----@param end_col integer
+---@param range Range4
 ---@return string
-local function get_range_str(lnum, col, end_lnum, end_col)
-  if lnum == end_lnum then
-    return string.format('[%d:%d - %d]', lnum + 1, col + 1, end_col)
-  end
-  return string.format('[%d:%d - %d:%d]', lnum + 1, col + 1, end_lnum + 1, end_col)
+local function range_to_string(range)
+  ---@type integer, integer, integer, integer
+  local row, col, end_row, end_col = unpack(range)
+  return string.format('[%d, %d] - [%d, %d]', row, col, end_row, end_col)
 end
 
 ---@param w integer
@@ -212,7 +213,7 @@ function TSTreeView:draw(bufnr)
   local lang_hl_marks = {} ---@type table[]
 
   for i, item in self:iter() do
-    local range_str = get_range_str(item.node:range())
+    local range_str = range_to_string({ item.node:range() })
     local lang_str = self.opts.lang and string.format(' %s', item.lang) or ''
 
     local text ---@type string
diff --git a/test/functional/treesitter/inspect_tree_spec.lua b/test/functional/treesitter/inspect_tree_spec.lua
new file mode 100644
index 0000000000..0102838b82
--- /dev/null
+++ b/test/functional/treesitter/inspect_tree_spec.lua
@@ -0,0 +1,109 @@
+local helpers = require('test.functional.helpers')(after_each)
+local clear = helpers.clear
+local insert = helpers.insert
+local dedent = helpers.dedent
+local eq = helpers.eq
+local exec_lua = helpers.exec_lua
+local feed = helpers.feed
+
+describe('vim.treesitter.inspect_tree', function()
+  before_each(clear)
+
+  local expect_tree = function(x)
+    local expected = vim.split(vim.trim(dedent(x)), '\n')
+    local actual = helpers.buf_lines(0) ---@type string[]
+    eq(expected, actual)
+  end
+
+  it('working', function()
+    insert([[
+      print()
+      ]])
+
+    exec_lua([[
+      vim.treesitter.start(0, 'lua')
+      vim.treesitter.inspect_tree()
+    ]])
+
+    expect_tree [[
+      (function_call ; [0, 0] - [0, 7]
+        name: (identifier) ; [0, 0] - [0, 5]
+        arguments: (arguments)) ; [0, 5] - [0, 7]
+      ]]
+  end)
+
+  it('can toggle to show anonymous nodes', function()
+    insert([[
+      print()
+      ]])
+
+    exec_lua([[
+      vim.treesitter.start(0, 'lua')
+      vim.treesitter.inspect_tree()
+    ]])
+    feed('a')
+
+    expect_tree [[
+      (function_call ; [0, 0] - [0, 7]
+        name: (identifier) ; [0, 0] - [0, 5]
+        arguments: (arguments ; [0, 5] - [0, 7]
+          "(" ; [0, 5] - [0, 6]
+          ")")) ; [0, 6] - [0, 7]
+      ]]
+  end)
+
+  it('works for injected trees', function()
+    insert([[
+      ```lua
+      return
+      ```
+      ]])
+
+    exec_lua([[
+      vim.treesitter.start(0, 'markdown')
+      vim.treesitter.get_parser():parse()
+      vim.treesitter.inspect_tree()
+    ]])
+
+    expect_tree [[
+      (section ; [0, 0] - [4, 0]
+        (fenced_code_block ; [0, 0] - [3, 0]
+          (fenced_code_block_delimiter) ; [0, 0] - [0, 3]
+          (info_string ; [0, 3] - [0, 6]
+            (language)) ; [0, 3] - [0, 6]
+          (block_continuation) ; [1, 0] - [1, 0]
+          (code_fence_content ; [1, 0] - [2, 0]
+            (return_statement) ; [1, 0] - [1, 6]
+            (block_continuation)) ; [2, 0] - [2, 0]
+          (fenced_code_block_delimiter))) ; [2, 0] - [2, 3]
+      ]]
+  end)
+
+  it('can toggle to show languages', function()
+    insert([[
+      ```lua
+      return
+      ```
+      ]])
+
+    exec_lua([[
+      vim.treesitter.start(0, 'markdown')
+      vim.treesitter.get_parser():parse()
+      vim.treesitter.inspect_tree()
+    ]])
+    feed('I')
+
+    expect_tree [[
+      (section ; [0, 0] - [4, 0] markdown
+        (fenced_code_block ; [0, 0] - [3, 0] markdown
+          (fenced_code_block_delimiter) ; [0, 0] - [0, 3] markdown
+          (info_string ; [0, 3] - [0, 6] markdown
+            (language)) ; [0, 3] - [0, 6] markdown
+          (block_continuation) ; [1, 0] - [1, 0] markdown
+          (code_fence_content ; [1, 0] - [2, 0] markdown
+            (return_statement) ; [1, 0] - [1, 6] lua
+            (block_continuation)) ; [2, 0] - [2, 0] markdown
+          (fenced_code_block_delimiter))) ; [2, 0] - [2, 3] markdown
+      ]]
+  end)
+end)