From 3cd45c45a3159fe29222c6e4c96da34de79425a3 Mon Sep 17 00:00:00 2001
From: Oleksandr Smirnov <olexsmir@gmail.com>
Date: Thu, 4 Sep 2025 14:17:58 +0300
Subject: [PATCH] feat(comment): add comment on on interface method

---
 lua/gopher/_utils/init.lua                    | 11 ++++++++-
 lua/gopher/_utils/ts.lua                      | 13 +++++++---
 lua/gopher/comment.lua                        | 24 ++++++++++++-------
 .../comment/interface_many_method_input.go    |  6 +++++
 .../comment/interface_many_method_output.go   |  7 ++++++
 .../comment/interface_method_input.go         |  5 ++++
 .../comment/interface_method_output.go        |  6 +++++
 spec/integration/comment_test.lua             |  8 +++++++
 spec/unit/utils_test.lua                      | 24 +++++++++++++++++++
 9 files changed, 91 insertions(+), 13 deletions(-)
 create mode 100644 spec/fixtures/comment/interface_many_method_input.go
 create mode 100644 spec/fixtures/comment/interface_many_method_output.go
 create mode 100644 spec/fixtures/comment/interface_method_input.go
 create mode 100644 spec/fixtures/comment/interface_method_output.go

diff --git a/lua/gopher/_utils/init.lua b/lua/gopher/_utils/init.lua
index e176345..1d717a9 100644
--- a/lua/gopher/_utils/init.lua
+++ b/lua/gopher/_utils/init.lua
@@ -3,7 +3,7 @@ local log = require "gopher._utils.log"
 local utils = {}
 
 ---@param msg string
----@param lvl? number by default `vim.log.levels.INFO`
+---@param lvl? integer by default `vim.log.levels.INFO`
 function utils.notify(msg, lvl)
   lvl = lvl or vim.log.levels.INFO
   vim.notify(msg, lvl, {
@@ -38,4 +38,13 @@ function utils.trimend(s)
   return r
 end
 
+-- Since indentation can be spaces or tab, that's my hack around it
+---@param line string
+---@param indent integer
+---@return string
+function utils.indent(line, indent)
+  local char = string.sub(line, 1, 1)
+  return string.rep(char, indent)
+end
+
 return utils
diff --git a/lua/gopher/_utils/ts.lua b/lua/gopher/_utils/ts.lua
index a0623ad..0b88b64 100644
--- a/lua/gopher/_utils/ts.lua
+++ b/lua/gopher/_utils/ts.lua
@@ -13,7 +13,8 @@ local queries = {
   ]],
   func = [[
     [(function_declaration name: (identifier)       @_name)
-     (method_declaration   name: (field_identifier) @_name)]
+     (method_declaration   name: (field_identifier) @_name)
+     (method_elem          name: (field_identifier) @_name)]
   ]],
   package = [[
     (package_identifier) @_name
@@ -67,6 +68,7 @@ end
 ---@field name string
 ---@field start integer
 ---@field end_ integer
+---@field indent integer
 ---@field is_varstruct boolean
 
 ---@param bufnr integer
@@ -94,7 +96,8 @@ local function do_stuff(bufnr, parent_type, query)
   local res = get_captures(q, parent_node, bufnr)
   assert(res.name ~= nil, "No capture name found")
 
-  local start_row, _, end_row, _ = parent_node:range()
+  local start_row, start_col, end_row, _ = parent_node:range()
+  res["indent"] = start_col
   res["start"] = start_row + 1
   res["end_"] = end_row + 1
 
@@ -120,7 +123,11 @@ end
 ---@param bufnr integer
 function ts.get_func_under_cursor(bufnr)
   --- since this handles both and funcs and methods we should check for both parent nodes
-  return do_stuff(bufnr, { "function_declaration", "method_declaration" }, queries.func)
+  return do_stuff(bufnr, {
+    "method_elem",
+    "function_declaration",
+    "method_declaration",
+  }, queries.func)
 end
 
 ---@param bufnr integer
diff --git a/lua/gopher/comment.lua b/lua/gopher/comment.lua
index e5cecd8..0192e51 100644
--- a/lua/gopher/comment.lua
+++ b/lua/gopher/comment.lua
@@ -7,25 +7,27 @@
 
 local ts = require "gopher._utils.ts"
 local log = require "gopher._utils.log"
+local u = require "gopher._utils"
 local comment = {}
 
 ---@param bufnr integer
+---@param line string
 ---@return string
 ---@dochide
-local function generate(bufnr)
+local function generate(bufnr, line)
   local s_ok, s_res = pcall(ts.get_struct_under_cursor, bufnr)
   if s_ok then
-    return "// " .. s_res.name .. " "
+    return u.indent(line, s_res.indent) .. "// " .. s_res.name .. " "
   end
 
   local f_ok, f_res = pcall(ts.get_func_under_cursor, bufnr)
   if f_ok then
-    return "// " .. f_res.name .. " "
+    return u.indent(line, f_res.indent) .. "// " .. f_res.name .. " "
   end
 
   local i_ok, i_res = pcall(ts.get_interface_under_cursor, bufnr)
   if i_ok then
-    return "// " .. i_res.name .. " "
+    return u.indent(line, i_res.indent) .. "// " .. i_res.name .. " "
   end
 
   local p_ok, p_res = pcall(ts.get_package_under_cursor, bufnr)
@@ -38,12 +40,16 @@ end
 
 function comment.comment()
   local bufnr = vim.api.nvim_get_current_buf()
-  local cmt = generate(bufnr)
-  log.debug("generated comment: " .. cmt)
+  local lnum = vim.fn.getcurpos()[2]
+  local line = vim.fn.getline(lnum)
+  local cmt = generate(bufnr, line)
+  log.debug("generated comment:", {
+    comment = cmt,
+    line = line,
+  })
 
-  local pos = vim.fn.getcurpos()[2]
-  vim.fn.append(pos - 1, cmt)
-  vim.fn.setpos(".", { 0, pos, #cmt })
+  vim.fn.append(lnum - 1, cmt)
+  vim.fn.setpos(".", { bufnr, lnum, #cmt })
   vim.cmd "startinsert!"
 end
 
diff --git a/spec/fixtures/comment/interface_many_method_input.go b/spec/fixtures/comment/interface_many_method_input.go
new file mode 100644
index 0000000..e5dca33
--- /dev/null
+++ b/spec/fixtures/comment/interface_many_method_input.go
@@ -0,0 +1,6 @@
+package main
+
+type Testinger interface {
+	Get(id string) int
+	Set(id string, val int)
+}
diff --git a/spec/fixtures/comment/interface_many_method_output.go b/spec/fixtures/comment/interface_many_method_output.go
new file mode 100644
index 0000000..cdeb97c
--- /dev/null
+++ b/spec/fixtures/comment/interface_many_method_output.go
@@ -0,0 +1,7 @@
+package main
+
+type Testinger interface {
+	Get(id string) int
+	// Set 
+	Set(id string, val int)
+}
diff --git a/spec/fixtures/comment/interface_method_input.go b/spec/fixtures/comment/interface_method_input.go
new file mode 100644
index 0000000..7e39a39
--- /dev/null
+++ b/spec/fixtures/comment/interface_method_input.go
@@ -0,0 +1,5 @@
+package main
+
+type Testinger interface {
+	Method(input string) error
+}
diff --git a/spec/fixtures/comment/interface_method_output.go b/spec/fixtures/comment/interface_method_output.go
new file mode 100644
index 0000000..5fa2388
--- /dev/null
+++ b/spec/fixtures/comment/interface_method_output.go
@@ -0,0 +1,6 @@
+package main
+
+type Testinger interface {
+	// Method 
+	Method(input string) error
+}
diff --git a/spec/integration/comment_test.lua b/spec/integration/comment_test.lua
index fdf39fe..b727239 100644
--- a/spec/integration/comment_test.lua
+++ b/spec/integration/comment_test.lua
@@ -30,6 +30,14 @@ comment["should add comment to interface"] = function()
   do_the_test("interface", { 3, 6 })
 end
 
+comment["should add comment on interface method"] = function()
+  do_the_test("interface_method", { 4, 2 })
+end
+
+comment["should add a comment on interface with many method"] = function()
+  do_the_test("interface_many_method", { 5, 2 })
+end
+
 comment["otherwise should add // above cursor"] = function()
   do_the_test("empty", { 1, 1 })
 end
diff --git a/spec/unit/utils_test.lua b/spec/unit/utils_test.lua
index d4898c2..2d8f0bc 100644
--- a/spec/unit/utils_test.lua
+++ b/spec/unit/utils_test.lua
@@ -22,4 +22,28 @@ utils["should .trimend()"] = function()
   t.eq(u.trimend "  hi   ", "  hi")
 end
 
+utils["should add .indent() spaces"] = function()
+  local u = require "gopher._utils"
+  local line = "    func Test() error {"
+  local indent = 4
+
+  t.eq("    ", u.indent(line, indent))
+end
+
+utils["should add .indent() a tab"] = function()
+  local u = require "gopher._utils"
+  local line = "\tfunc Test() error {"
+  local indent = 1
+
+  t.eq("\t", u.indent(line, indent))
+end
+
+utils["should add .indent() 2 tabs"] = function()
+  local u = require "gopher._utils"
+  local line = "\t\tfunc Test() error {"
+  local indent = 2
+
+  t.eq("\t\t", u.indent(line, indent))
+end
+
 return T