diff --git a/spec/execute_spec.lua b/spec/execute_spec.lua
index 8fc46a6..dfcd705 100644
--- a/spec/execute_spec.lua
+++ b/spec/execute_spec.lua
@@ -8,7 +8,6 @@ describe('cp.execute', function()
     mock_system_calls = {}
     temp_files = {}
 
-    local original_system = vim.system
     vim.system = function(cmd, opts)
       table.insert(mock_system_calls, { cmd = cmd, opts = opts })
       if not cmd or #cmd == 0 then
@@ -52,7 +51,6 @@ describe('cp.execute', function()
       end,
     })
 
-    local original_uv = vim.uv
     vim.uv = vim.tbl_extend('force', vim.uv or {}, {
       hrtime = function()
         return 1000000000
@@ -135,7 +133,7 @@ describe('cp.execute', function()
     end)
 
     it('handles compilation errors gracefully', function()
-      vim.system = function(cmd, opts)
+      vim.system = function()
         return {
           wait = function()
             return { code = 1, stderr = 'error: undefined variable' }
@@ -218,7 +216,7 @@ describe('cp.execute', function()
     end)
 
     it('captures stderr output', function()
-      vim.system = function(cmd, opts)
+      vim.system = function()
         return {
           wait = function()
             return { code = 1, stdout = '', stderr = 'runtime error\n' }
@@ -278,16 +276,10 @@ describe('cp.execute', function()
   describe('language detection', function()
     it('detects cpp from extension', function()
       -- This tests get_language_from_file indirectly
-      local contest_config = {
-        default_language = 'python',
-      }
 
       -- Mock the file extension detection
-      vim.fn.fnamemodify = function(path, modifier)
-        if modifier == ':e' and path == 'test.cpp' then
-          return 'cpp'
-        end
-        return ''
+      vim.fn.fnamemodify = function()
+        return 'cpp'
       end
 
       -- The actual function is local, but we can test it indirectly
diff --git a/spec/integration_spec.lua b/spec/integration_spec.lua
index 60f97db..86b9063 100644
--- a/spec/integration_spec.lua
+++ b/spec/integration_spec.lua
@@ -166,7 +166,7 @@ describe('cp integration', function()
       }
 
       temp_files['test.run'] = {}
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         return {
           wait = function()
             return { code = 0, stdout = '3\n', stderr = '' }
@@ -200,7 +200,7 @@ describe('cp integration', function()
     end)
 
     it('handles scraper communication properly', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if cmd[1] == 'uv' and vim.tbl_contains(cmd, 'metadata') then
           return {
             wait = function()
@@ -231,7 +231,7 @@ describe('cp integration', function()
     end)
 
     it('processes scraper output correctly', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if vim.tbl_contains(cmd, 'metadata') then
           return {
             wait = function()
@@ -338,7 +338,7 @@ describe('cp integration', function()
     end)
 
     it('recovers from interrupted operations', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if vim.tbl_contains(cmd, 'metadata') then
           return {
             wait = function()
@@ -393,7 +393,7 @@ describe('cp integration', function()
     end)
 
     it('maintains system stability on errors', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if vim.tbl_contains(cmd, 'metadata') then
           return {
             wait = function()
@@ -422,7 +422,7 @@ describe('cp integration', function()
         table.insert(large_problems, { id = string.char(96 + i % 26), name = 'Problem ' .. i })
       end
 
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if vim.tbl_contains(cmd, 'metadata') then
           return {
             wait = function()
@@ -462,7 +462,7 @@ describe('cp integration', function()
 
     it('maintains responsiveness during operations', function()
       local call_count = 0
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         call_count = call_count + 1
         vim.wait(10)
         return {
diff --git a/spec/scraper_spec.lua b/spec/scraper_spec.lua
index 5614fd7..d6c5f1d 100644
--- a/spec/scraper_spec.lua
+++ b/spec/scraper_spec.lua
@@ -17,7 +17,6 @@ describe('cp.scrape', function()
 
     mock_system_calls = {}
 
-    local original_system = vim.system
     vim.system = function(cmd, opts)
       table.insert(mock_system_calls, { cmd = cmd, opts = opts })
 
@@ -26,7 +25,7 @@ describe('cp.scrape', function()
       if cmd[1] == 'ping' then
         result = { code = 0 }
       elseif cmd[1] == 'uv' and cmd[2] == 'sync' then
-        result = { code = 0 }
+        result = { code = 0, stdout = '', stderr = '' }
       elseif cmd[1] == 'uv' and cmd[2] == 'run' then
         if vim.tbl_contains(cmd, 'metadata') then
           result.stdout = '{"success": true, "problems": [{"id": "a", "name": "Test Problem"}]}'
@@ -124,10 +123,7 @@ describe('cp.scrape', function()
   describe('system dependency checks', function()
     it('handles missing uv executable', function()
       vim.fn.executable = function(cmd)
-        if cmd == 'uv' then
-          return 0
-        end
-        return 1
+        return cmd == 'uv' and 0 or 1
       end
 
       local result = scrape.scrape_contest_metadata('atcoder', 'abc123')
@@ -137,7 +133,7 @@ describe('cp.scrape', function()
     end)
 
     it('handles python environment setup failure', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if cmd[1] == 'ping' then
           return {
             wait = function()
@@ -169,7 +165,7 @@ describe('cp.scrape', function()
     end)
 
     it('handles network connectivity issues', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if cmd[1] == 'ping' then
           return {
             wait = function()
@@ -228,7 +224,7 @@ describe('cp.scrape', function()
     end)
 
     it('handles subprocess execution failure', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if cmd[1] == 'ping' then
           return {
             wait = function()
@@ -259,7 +255,7 @@ describe('cp.scrape', function()
 
   describe('json parsing', function()
     it('handles invalid json output', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if cmd[1] == 'ping' then
           return {
             wait = function()
@@ -287,7 +283,7 @@ describe('cp.scrape', function()
     end)
 
     it('handles scraper-reported failures', function()
-      vim.system = function(cmd, opts)
+      vim.system = function(cmd)
         if cmd[1] == 'ping' then
           return {
             wait = function()