feat(lsp): adjust completion textEdit range to replace typed word (#303)

refactor(lsp): pass word to to_lsp_item for accurate replacement
test(lsp): add test for correct textEdit range in completion items

Author: khaitranhq

lua/opencode/lsp/opencode_ls.lua

@@ -91,14 +91,20 @@ end
 ---Convert opencode CompletionItem to LSP CompletionItem
 ---@param item CompletionItem
 ---@param index integer
+---@param params lsp.CompletionParams
+---@param word string Text after the trigger character to be completed
 ---@return OpencodeLspItem
-local function to_lsp_item(item, index, params)
+local function to_lsp_item(item, index, params, word)
   local source = require('opencode.ui.completion').get_source_by_name(item.source_name)
-  local kind = (source and source.custom_kind) or vim.lsp.protocol.CompletionItemKind.Function ---@type lsp.CompletionItemKind
+  local kind = (source and source.custom_kind) or
+  vim.lsp.protocol.CompletionItemKind.Function ---@type lsp.CompletionItemKind
   local priority = source and source.priority or 999
   local line = params.position.line
   local col = params.position.character
 
+  local start_char = col - #word
+  local end_char = col
+
   ---@type OpencodeLspItem
   local lsp_item = {
     label = (M.supports_kind_icons() and '' or item.kind_icon .. ' ') .. item.label,
@@ -115,8 +121,8 @@ local function to_lsp_item(item, index, params)
     sortText = string.format('%02d_%02d_%02d_%s', priority, item.priority or 999, index, item.label),
     textEdit = {
       range = {
-        start = { line = line, character = col },
-        ['end'] = { line = line, character = col },
+        start = { line = line, character = start_char },
+        ['end'] = { line = line, character = end_char },
       },
       newText = item.insert_text,
     },
@@ -161,29 +167,29 @@ handlers[ms.textDocument_completion] = function(params, callback)
   end
 
   Promise.all(promises)
-    :and_then(function(results)
-      ---@type OpencodeLspItem[]
-      local all_items = {}
-      local is_incomplete = false
-
-      for _, items in ipairs(results) do
-        for j, item in ipairs(items or {}) do
-          local source = completion.get_source_by_name(item.source_name)
-          if source and source.is_incomplete then
-            is_incomplete = true
+      :and_then(function(results)
+        ---@type OpencodeLspItem[]
+        local all_items = {}
+        local is_incomplete = false
+
+        for _, items in ipairs(results) do
+          for j, item in ipairs(items or {}) do
+            local source = completion.get_source_by_name(item.source_name)
+            if source and source.is_incomplete then
+              is_incomplete = true
+            end
+
+            table.insert(all_items, to_lsp_item(item, j, params, word))
           end
-
-          table.insert(all_items, to_lsp_item(item, j, params))
         end
-      end
 
-      callback(nil, { isIncomplete = is_incomplete, items = all_items })
-    end)
-    :catch(function(err)
-      local log = require('opencode.log')
-      log.error('Error in completion handler: ' .. tostring(err))
-      callback(nil, { isIncomplete = false, items = {} })
-    end)
+        callback(nil, { isIncomplete = is_incomplete, items = all_items })
+      end)
+      :catch(function(err)
+        local log = require('opencode.log')
+        log.error('Error in completion handler: ' .. tostring(err))
+        callback(nil, { isIncomplete = false, items = {} })
+      end)
 end
 
 ---Create the LSP server configuration
@@ -231,7 +237,7 @@ function M.start(bufnr)
       local completed_item = vim.v.completed_item
       if completed_item and completed_item.user_data then
         local data = vim.tbl_get(completed_item, 'user_data', 'nvim', 'lsp', 'completion_item', 'data')
-          or vim.tbl_get(completed_item, 'user_data', 'lsp', 'item', 'data')
+            or vim.tbl_get(completed_item, 'user_data', 'lsp', 'item', 'data')
 
         local item = data and data._opencode_item
 

tests/unit/completion_lsp_spec.lua

@@ -1019,68 +1019,136 @@ describe('opencode LSP completion', function()
       end)
 
       it('embeds the original item in data._opencode_item', function()
-        package.loaded['blink.cmp'] = nil
-        package.loaded['opencode.lsp.opencode_ls'] = nil
-        ls = require('opencode.lsp.opencode_ls')
-
-        package.loaded['opencode.ui.completion'] = nil
-        local completion = require('opencode.ui.completion')
-        completion._sources = {}
-
-        local original_item = {
-          label = 'OriginalItem',
-          kind = 'file',
-          kind_icon = '',
-          insert_text = 'OriginalItem',
-          source_name = 'data_test_source',
-          data = { custom = 'value' },
-        }
-
-        completion.register_source({
-          name = 'data_test_source',
-          priority = 1,
-          complete = function()
-            return Promise.new():resolve({ original_item })
-          end,
-          get_trigger_character = function()
-            return '@'
-          end,
-        })
-
-        vim.api.nvim_buf_get_lines = function()
-          return { '@test' }
-        end
-        vim.api.nvim_get_current_line = function()
-          return '@test'
-        end
-        vim.api.nvim_win_get_cursor = function()
-          return { 1, 5 }
-        end
-
-        local config_obj = ls.create_config()
-        local server = config_obj.cmd({}, {})
-
-        local done = false
-        local callback_result = nil
-        server.request('textDocument/completion', {
-          position = { line = 0, character = 5 },
-        }, function(err, result)
-          callback_result = result
-          done = true
-        end)
-
-        vim.wait(200, function()
-          return done
-        end)
-
-        assert.is_not_nil(callback_result)
-        assert.are.equal(1, #callback_result.items)
-        local lsp_item = callback_result.items[1]
-        assert.is_not_nil(lsp_item.data)
-        assert.is_not_nil(lsp_item.data._opencode_item)
-        assert.are.equal(original_item.label, lsp_item.data._opencode_item.label)
-        assert.are.equal('value', lsp_item.data._opencode_item.data.custom)
-      end)
+         package.loaded['blink.cmp'] = nil
+         package.loaded['opencode.lsp.opencode_ls'] = nil
+         ls = require('opencode.lsp.opencode_ls')
+
+         package.loaded['opencode.ui.completion'] = nil
+         local completion = require('opencode.ui.completion')
+         completion._sources = {}
+
+         local original_item = {
+           label = 'OriginalItem',
+           kind = 'file',
+           kind_icon = '',
+           insert_text = 'OriginalItem',
+           source_name = 'data_test_source',
+           data = { custom = 'value' },
+         }
+
+         completion.register_source({
+           name = 'data_test_source',
+           priority = 1,
+           complete = function()
+             return Promise.new():resolve({ original_item })
+           end,
+           get_trigger_character = function()
+             return '@'
+           end,
+         })
+
+         vim.api.nvim_buf_get_lines = function()
+           return { '@test' }
+         end
+         vim.api.nvim_get_current_line = function()
+           return '@test'
+         end
+         vim.api.nvim_win_get_cursor = function()
+           return { 1, 5 }
+         end
+
+         local config_obj = ls.create_config()
+         local server = config_obj.cmd({}, {})
+
+         local done = false
+         local callback_result = nil
+         server.request('textDocument/completion', {
+           position = { line = 0, character = 5 },
+         }, function(err, result)
+           callback_result = result
+           done = true
+         end)
+
+         vim.wait(200, function()
+           return done
+         end)
+
+         assert.is_not_nil(callback_result)
+         assert.are.equal(1, #callback_result.items)
+         local lsp_item = callback_result.items[1]
+         assert.is_not_nil(lsp_item.data)
+         assert.is_not_nil(lsp_item.data._opencode_item)
+         assert.are.equal(original_item.label, lsp_item.data._opencode_item.label)
+         assert.are.equal('value', lsp_item.data._opencode_item.data.custom)
+       end)
+
+       it('calculates correct textEdit range to replace typed word', function()
+         package.loaded['blink.cmp'] = nil
+         package.loaded['opencode.lsp.opencode_ls'] = nil
+         ls = require('opencode.lsp.opencode_ls')
+
+         package.loaded['opencode.ui.completion'] = nil
+         local completion = require('opencode.ui.completion')
+         completion._sources = {}
+
+         local item_for_range_test = {
+           label = 'tests',
+           kind = 'file',
+           kind_icon = '',
+           insert_text = 'tests',
+           source_name = 'range_test_source',
+           data = {},
+         }
+
+         completion.register_source({
+           name = 'range_test_source',
+           priority = 1,
+           complete = function()
+             return Promise.new():resolve({ item_for_range_test })
+           end,
+           get_trigger_character = function()
+             return '@'
+           end,
+         })
+
+         vim.api.nvim_buf_get_lines = function()
+           return { '@te' }
+         end
+         vim.api.nvim_get_current_line = function()
+           return '@te'
+         end
+         vim.api.nvim_win_get_cursor = function()
+           return { 1, 3 }
+         end
+
+         local config_obj = ls.create_config()
+         local server = config_obj.cmd({}, {})
+
+         local done = false
+         local callback_result = nil
+         server.request('textDocument/completion', {
+           position = { line = 0, character = 3 },
+         }, function(err, result)
+           callback_result = result
+           done = true
+         end)
+
+         vim.wait(200, function()
+           return done
+         end)
+
+         assert.is_not_nil(callback_result)
+         assert.are.equal(1, #callback_result.items)
+         local lsp_item = callback_result.items[1]
+         assert.is_not_nil(lsp_item.textEdit)
+         assert.is_not_nil(lsp_item.textEdit.range)
+
+         local range = lsp_item.textEdit.range
+         assert.are.equal(1, range.start.character, 'start should be at trigger char position + 1')
+         assert.are.equal(3, range['end'].character, 'end should be at cursor position')
+         assert.are.equal(0, range.start.line, 'line should be 0')
+         assert.are.equal(0, range['end'].line, 'line should be 0')
+       end)
     end)
   end)
 end)