diff --git a/lua/gitlinker/logger.lua b/lua/gitlinker/logger.lua
index e2cac71..a6f42ba 100644
--- a/lua/gitlinker/logger.lua
+++ b/lua/gitlinker/logger.lua
@@ -42,7 +42,7 @@ local Configs = {
     ),
 }
 
---- @param opts table<any, any>
+--- @param opts Options?
 local function setup(opts)
     Configs = vim.tbl_deep_extend("force", vim.deepcopy(Configs), opts or {})
     if type(Configs.level) == "string" then
diff --git a/lua/gitlinker/util.lua b/lua/gitlinker/util.lua
index 268919a..1491bc9 100644
--- a/lua/gitlinker/util.lua
+++ b/lua/gitlinker/util.lua
@@ -56,19 +56,19 @@ end
 
 --- @return {lstart:integer,lend:integer}
 local function line_range()
-    local mode = vim.fn.mode()
-    local pos1 = nil
-    local pos2 = nil
-    if is_visual_mode(mode) then
+    local m = vim.fn.mode()
+    local l1 = nil
+    local l2 = nil
+    if is_visual_mode(m) then
         vim.cmd([[execute "normal! \<ESC>"]])
-        pos1 = vim.fn.getpos("'<")[2]
-        pos2 = vim.fn.getpos("'>")[2]
+        l1 = vim.fn.getpos("'<")[2]
+        l2 = vim.fn.getpos("'>")[2]
     else
-        pos1 = vim.fn.getcurpos()[2]
-        pos2 = pos1
+        l1 = vim.fn.getcurpos()[2]
+        l2 = l1
     end
-    local lstart = math.min(pos1, pos2)
-    local lend = math.max(pos1, pos2)
+    local lstart = math.min(l1, l2)
+    local lend = math.max(l1, l2)
     return { lstart = lstart, lend = lend }
 end
 
diff --git a/test/util_spec.lua b/test/util_spec.lua
new file mode 100644
index 0000000..ca9642b
--- /dev/null
+++ b/test/util_spec.lua
@@ -0,0 +1,50 @@
+local cwd = vim.fn.getcwd()
+
+describe("util", function()
+    local assert_eq = assert.is_equal
+    local assert_true = assert.is_true
+    local assert_false = assert.is_false
+
+    before_each(function()
+        vim.api.nvim_command("cd " .. cwd)
+        vim.opt.swapfile = false
+    end)
+
+    local logger = require("gitlinker.logger")
+    logger.setup()
+    local util = require("gitlinker.util")
+    describe("[path_normalize]", function()
+        it("normalize", function()
+            local lines = {
+                "~/github/linrongbin16/gitlinker.nvim/README.md",
+                "~/github/linrongbin16/gitlinker.nvim/lua/gitlinker.lua",
+            }
+            for i, line in ipairs(lines) do
+                local actual = util.path_normalize(line)
+                local expect = vim.fn.expand(line)
+                print(
+                    string.format(
+                        "path normalize[%d]:%s == %s\n",
+                        i,
+                        actual,
+                        expect
+                    )
+                )
+                assert_eq(actual, expect)
+            end
+        end)
+        it("relative", function()
+            local lines = {
+                "README.md",
+                "lua/gitlinker.lua",
+                "lua/gitlinker/util.lua",
+            }
+            for i, line in ipairs(lines) do
+                vim.cmd(string.format([[ edit %s ]], line))
+                local actual = util.path_relative()
+                print(string.format("path relative:%s\n", actual))
+                assert_eq(actual, line)
+            end
+        end)
+    end)
+end)