fix(commands): address copilot review findings

- include allowed subcommands in agent/session/diff invalid argument errors

- clamp help table column width in narrow windows to avoid format failures

- fail run_tests.sh on non-zero nvim/plenary exits in addition to output parsing

- add handlers tests for actionable subcommand errors and narrow-window help rendering

Author: jensenojs

lua/opencode/commands/handlers/agent.lua

@@ -84,7 +84,7 @@ M.command_defs = {
     execute = function(args)
       local action = agent_subcommand_calls[args[1]]
       if not action then
-        invalid_arguments('Invalid agent subcommand')
+        invalid_arguments('Invalid agent subcommand. Use: ' .. table.concat(agent_subcommands, ', '))
       end
       return action()
     end,

lua/opencode/commands/handlers/diff.lua

@@ -155,7 +155,7 @@ M.command_defs = {
       local subcommand = args[1] or 'open'
       local action = diff_subcommand_actions[subcommand]
       if not action then
-        invalid_arguments('Invalid diff subcommand')
+        invalid_arguments('Invalid diff subcommand. Use: ' .. table.concat(diff_subcommands, ', '))
       end
       return action()
     end,

lua/opencode/commands/handlers/session.lua

@@ -434,7 +434,7 @@ M.command_defs = {
       local subcommand = args[1]
       local action = session_subcommand_actions[subcommand]
       if not action then
-        invalid_arguments('Invalid session subcommand')
+        invalid_arguments('Invalid session subcommand. Use: ' .. table.concat(session_subcommands, ', '))
       end
       return action(args)
     end,

lua/opencode/commands/handlers/surface.lua

@@ -68,7 +68,7 @@ function M.actions.help()
     return
   end
 
-  local max_desc_length = math.min(90, nvim.nvim_win_get_width(state.windows.output_win) - 35)
+  local max_desc_length = math.max(10, math.min(90, nvim.nvim_win_get_width(state.windows.output_win) - 35))
 
   local command_defs = get_command_definitions()
   local sorted_commands = vim.tbl_keys(command_defs)

run_tests.sh

@@ -86,12 +86,17 @@ has_failures() {
 minimal_output=""
 unit_output=""
 replay_output=""
+minimal_status=0
+unit_status=0
+replay_status=0
+specific_status=0
 
 if [ "$TEST_TYPE" = "all" ] || [ "$TEST_TYPE" = "minimal" ]; then
     minimal_output=$(nvim --headless -u tests/minimal/init.lua -c "lua require('plenary.test_harness').test_directory('./tests/minimal', {minimal_init = './tests/minimal/init.lua', sequential = true$FILTER_OPTION})" 2>&1)
+    minimal_status=$?
     clean_output "$minimal_output"
 
-    if has_failures "$minimal_output"; then
+    if [ "$minimal_status" -ne 0 ] || has_failures "$minimal_output"; then
         echo -e "${RED}✗ Minimal tests failed${NC}"
     else
         echo -e "${GREEN}✓ Minimal tests passed${NC}"
@@ -101,9 +106,10 @@ fi
 
 if [ "$TEST_TYPE" = "all" ] || [ "$TEST_TYPE" = "unit" ]; then
     unit_output=$(nvim --headless -u tests/minimal/init.lua -c "lua require('plenary.test_harness').test_directory('./tests/unit', {minimal_init = './tests/minimal/init.lua'$FILTER_OPTION})" 2>&1)
+    unit_status=$?
     clean_output "$unit_output"
 
-    if has_failures "$unit_output"; then
+    if [ "$unit_status" -ne 0 ] || has_failures "$unit_output"; then
         echo -e "${RED}✗ Unit tests failed${NC}"
     else
         echo -e "${GREEN}✓ Unit tests passed${NC}"
@@ -113,9 +119,10 @@ fi
 
 if [ "$TEST_TYPE" = "all" ] || [ "$TEST_TYPE" = "replay" ]; then
     replay_output=$(nvim --headless -u tests/minimal/init.lua -c "lua require('plenary.test_harness').test_directory('./tests/replay', {minimal_init = './tests/minimal/init.lua'$FILTER_OPTION})" 2>&1)
+    replay_status=$?
     clean_output "$replay_output"
 
-    if has_failures "$replay_output"; then
+    if [ "$replay_status" -ne 0 ] || has_failures "$replay_output"; then
         echo -e "${RED}✗ Replay tests failed${NC}"
     else
         echo -e "${GREEN}✓ Replay tests passed${NC}"
@@ -127,9 +134,10 @@ fi
 if [ "$TEST_TYPE" != "all" ] && [ "$TEST_TYPE" != "minimal" ] && [ "$TEST_TYPE" != "unit" ] && [ "$TEST_TYPE" != "replay" ]; then
     if [ -f "$TEST_TYPE" ]; then
         specific_output=$(nvim --headless -u tests/minimal/init.lua -c "lua require('plenary.test_harness').test_directory('./$TEST_TYPE', {minimal_init = './tests/minimal/init.lua'$FILTER_OPTION})" 2>&1)
+        specific_status=$?
         clean_output "$specific_output"
 
-        if has_failures "$specific_output"; then
+        if [ "$specific_status" -ne 0 ] || has_failures "$specific_output"; then
             echo -e "${RED}✗ Specific test failed${NC}"
         else
             echo -e "${GREEN}✓ Specific test passed${NC}"
@@ -148,9 +156,26 @@ all_output="$minimal_output
 $unit_output
 $replay_output"
 
-if has_failures "$all_output"; then
+if has_failures "$all_output" \
+    || [ "$minimal_status" -ne 0 ] \
+    || [ "$unit_status" -ne 0 ] \
+    || [ "$replay_status" -ne 0 ] \
+    || [ "$specific_status" -ne 0 ]; then
     echo -e "\n${RED}======== TEST FAILURES SUMMARY ========${NC}"
 
+    if [ "$minimal_status" -ne 0 ]; then
+        echo -e "${RED}Runner exit:${NC} minimal tests exited with code $minimal_status"
+    fi
+    if [ "$unit_status" -ne 0 ]; then
+        echo -e "${RED}Runner exit:${NC} unit tests exited with code $unit_status"
+    fi
+    if [ "$replay_status" -ne 0 ]; then
+        echo -e "${RED}Runner exit:${NC} replay tests exited with code $replay_status"
+    fi
+    if [ "$specific_status" -ne 0 ]; then
+        echo -e "${RED}Runner exit:${NC} specific tests exited with code $specific_status"
+    fi
+
     # Extract and format failures
     failures_file=$(mktemp)
     plain_output=$(strip_ansi "$all_output")

tests/unit/commands_handlers_spec.lua

@@ -1,4 +1,5 @@
 local assert = require('luassert')
+local stub = require('luassert.stub')
 
 describe('opencode.commands.handlers', function()
   local tracked_modules = {
@@ -110,6 +111,64 @@ describe('opencode.commands.handlers', function()
     }, err)
   end)
 
+  it('returns actionable invalid subcommand errors for agent/session/diff handlers', function()
+    local agent = require('opencode.commands.handlers.agent')
+    local session = require('opencode.commands.handlers.session')
+    local diff = require('opencode.commands.handlers.diff')
+
+    local ok_agent, err_agent = pcall(agent.command_defs.agent.execute, { 'unknown' })
+    local ok_session, err_session = pcall(session.command_defs.session.execute, { 'unknown' })
+    local ok_diff, err_diff = pcall(diff.command_defs.diff.execute, { 'unknown' })
+
+    assert.is_false(ok_agent)
+    assert.same({
+      code = 'invalid_arguments',
+      message = 'Invalid agent subcommand. Use: ' .. table.concat(agent.command_defs.agent.completions, ', '),
+    }, err_agent)
+
+    assert.is_false(ok_session)
+    assert.same({
+      code = 'invalid_arguments',
+      message = 'Invalid session subcommand. Use: ' .. table.concat(session.command_defs.session.completions, ', '),
+    }, err_session)
+
+    assert.is_false(ok_diff)
+    assert.same({
+      code = 'invalid_arguments',
+      message = 'Invalid diff subcommand. Use: ' .. table.concat(diff.command_defs.diff.completions, ', '),
+    }, err_diff)
+  end)
+
+  it('keeps help rendering stable in narrow output windows', function()
+    local surface = require('opencode.commands.handlers.surface')
+    local window = require('opencode.commands.handlers.window')
+    local state = require('opencode.state')
+    local ui = require('opencode.ui.ui')
+
+    local open_input_stub = stub(window.actions, 'open_input')
+    local is_visible_stub = stub(state.ui, 'is_visible').returns(true)
+    local set_route_stub = stub(state.ui, 'set_display_route')
+    local render_lines_stub = stub(ui, 'render_lines')
+    local width_stub = stub(vim.api, 'nvim_win_get_width').returns(20)
+
+    local original_windows = state.store.get('windows')
+    local test_windows = vim.deepcopy(original_windows or {})
+    test_windows.output_win = 1
+    state.store.set_raw('windows', test_windows)
+
+    local ok = pcall(surface.actions.help)
+
+    state.store.set_raw('windows', original_windows)
+    open_input_stub:revert()
+    is_visible_stub:revert()
+    set_route_stub:revert()
+    render_lines_stub:revert()
+    width_stub:revert()
+
+    assert.is_true(ok)
+    assert.stub(render_lines_stub).was_called()
+  end)
+
   it('keeps command semantic routing in diff revert handler (session target -> nil snapshot)', function()
     local called = {}
     local diff = require('opencode.commands.handlers.diff')