fix(struct_tags): edge case with structs declared as var (#99)

* fix(struct_tags): edge case with structs declared as var

* test: test it and fix it

* fixup! test: test it and fix it

* fixup! fix(struct_tags): edge case with structs declared as var

* fixup! test: test it and fix it

lua/gopher/_utils/ts.lua

···
 local ts = {}
 local queries = {
   struct = [[
-    (type_spec name: (type_identifier) @_name
-               type: (struct_type))
+    [(type_spec name: (type_identifier) @_name
+                type: (struct_type))
+     (var_declaration (var_spec
+                        name: (identifier) @_name @_var
+                        type: (struct_type)))
+     (short_var_declaration
+       left:  (expression_list (identifier) @_name @_var)
+       right: (expression_list (composite_literal
+                                 type: (struct_type))))]
   ]],
   func = [[
     [(function_declaration name: (identifier)       @_name)
···
 ---@param query vim.treesitter.Query
 ---@param node TSNode
 ---@param bufnr integer
----@return {name:string}
+---@return {name:string, is_varstruct:boolean}
 local function get_captures(query, node, bufnr)
   local res = {}
   for _, match, _ in query:iter_matches(node, bufnr) do
···
       if capture_name == "_name" then
         res["name"] = vim.treesitter.get_node_text(captured_node, bufnr)
       end
+
+      if capture_name == "_var" then
+        res["is_varstruct"] = true
+      end
     end
   end
 
···
 ---@field name string
 ---@field start_line integer
 ---@field end_line integer
+---@field is_varstruct boolean
 
 ---@param bufnr integer
 ---@param parent_type string[]
···
   --- should be both type_spec and type_declaration
   --- because in cases like `type ( T struct{}, U strict{} )`
   --- i will be choosing always last struct in the list
-  return do_stuff(bufnr, { "type_spec", "type_declaration" }, queries.struct)
+  ---
+  --- var_declaration is for cases like `var x struct{}`
+  --- short_var_declaration is for cases like `x := struct{}{}`
+  return do_stuff(bufnr, {
+    "type_spec",
+    "type_declaration",
+    "var_declaration",
+    "short_var_declaration",
+  }, queries.struct)
 end
 
 ---@param bufnr integer

lua/gopher/struct_tags.lua

···
     c.commands.gomodifytags,
     "-transform", c.gotag.transform,
     "-format", "json",
-    "-struct", st.name,
     "-file", fpath,
     "-w",
   }
+
+  if st.is_varstruct then
+    table.insert(cmd, "-line")
+    table.insert(cmd, string.format("%d,%d", st.start_line, st.end_line))
+  else
+    table.insert(cmd, "-struct")
+    table.insert(cmd, st.name)
+  end
 
   for _, v in ipairs(user_args) do
     table.insert(cmd, v)
···
   end
 
   local res = vim.json.decode(rs.stdout)
-
   if res["errors"] then
     log.error("tags: got an error " .. vim.inspect(res))
     error("failed to set tags " .. vim.inspect(res["errors"]))

spec/fixtures/tags/svar_input.go

···
+package main
+
+func main() {
+	s := struct {
+		API string
+		Key string
+	}{
+		API: "api.com",
+		Key: "key",
+	}
+}

spec/fixtures/tags/svar_output.go

···
+package main
+
+func main() {
+	s := struct {
+		API string `xml:"api"`
+		Key string `xml:"key"`
+	}{
+		API: "api.com",
+		Key: "key",
+	}
+}

spec/fixtures/tags/var_input.go

···
+package main
+
+func main() {
+	var a struct {
+		TestField1 string
+		TestField2 string
+	}
+}

spec/fixtures/tags/var_output.go

···
+package main
+
+func main() {
+	var a struct {
+		TestField1 string `yaml:"test_field_1"`
+		TestField2 string `yaml:"test_field_2"`
+	}
+}

spec/integration/struct_tags_test.lua

···
   t.eq(t.readfile(tmp), fixtures.output)
 end
 
+T["struct_tags"]["should add tags on var"] = function()
+  local tmp = t.tmpfile()
+  local fixtures = t.get_fixtures "tags/var"
+  t.writefile(tmp, fixtures.input)
+
+  child.cmd("silent edit " .. tmp)
+  child.fn.setpos(".", { child.fn.bufnr(tmp), 5, 3 })
+  child.cmd "GoTagAdd yaml"
+  child.cmd "write"
+
+  t.eq(t.readfile(tmp), fixtures.output)
+end
+
+T["struct_tags"]["should add tags on short declr var"] = function()
+  local tmp = t.tmpfile()
+  local fixtures = t.get_fixtures "tags/svar"
+  t.writefile(tmp, fixtures.input)
+
+  child.cmd("silent edit " .. tmp)
+  child.fn.setpos(".", { child.fn.bufnr(tmp), 4, 3 })
+  child.cmd "GoTagAdd xml"
+  child.cmd "write"
+
+  t.eq(t.readfile(tmp), fixtures.output)
+end
+
 return T