fix(ui): restore highlights after colorscheme changes

lua/opencode/ui/highlight.lua

@@ -1,7 +1,7 @@
 local M = {}
 
 ---Define the plugin highlight groups for the current background.
-function M.setup()
+local function apply_highlights()
   local is_light = vim.o.background == 'light'
 
   if is_light then
@@ -153,4 +153,18 @@ function M.setup()
   vim.api.nvim_set_hl(0, 'OpencodeCompactionFailed', { link = 'DiagnosticError', default = true })
 end
 
+function M.setup()
+  apply_highlights()
+
+  local group = vim.api.nvim_create_augroup('OpencodePluginHighlights', {
+    clear = true,
+  })
+
+  vim.api.nvim_create_autocmd('ColorScheme', {
+    group = group,
+    callback = apply_highlights,
+    desc = 'Restore opencode.nvim highlights after colorscheme changes',
+  })
+end
+
 return M

tests/unit/highlight_spec.lua

@@ -0,0 +1,44 @@
+local highlight = require('opencode.ui.highlight')
+
+describe('opencode highlight groups', function()
+  local name = 'OpencodeDialogOptionHover'
+
+  after_each(function()
+    pcall(vim.api.nvim_del_augroup_by_name, 'OpencodePluginHighlights')
+    vim.cmd.colorscheme('default')
+    vim.api.nvim_set_hl(0, name, {})
+  end)
+
+  it('restores highlights after a colorscheme change', function()
+    highlight.setup()
+
+    assert.is_not_nil(next(vim.api.nvim_get_hl(0, { name = name })))
+
+    vim.cmd.colorscheme('habamax')
+
+    assert.is_not_nil(next(vim.api.nvim_get_hl(0, { name = name })))
+  end)
+
+  it('preserves custom highlights', function()
+    highlight.setup()
+    vim.api.nvim_set_hl(0, name, { fg = '#123456' })
+
+    vim.api.nvim_exec_autocmds('ColorScheme', {
+      pattern = 'custom-theme',
+    })
+
+    assert.are.equal(0x123456, vim.api.nvim_get_hl(0, { name = name }).fg)
+  end)
+
+  it('registers only one ColorScheme handler', function()
+    highlight.setup()
+    highlight.setup()
+
+    local autocmds = vim.api.nvim_get_autocmds({
+      event = 'ColorScheme',
+      group = 'OpencodePluginHighlights',
+    })
+
+    assert.are.equal(1, #autocmds)
+  end)
+end)