feat(integrations): add visual mode multi-file selection for snacks.explorer

Enable selecting multiple files in snacks.explorer using vim's visual
mode. This brings the snacks.explorer integration up to par with others,
such as oil, nvim-tree and NvimTree

- Pass visual range parameters to _get_snacks_explorer_selection()
- Use picker's list API to convert row numbers to items (row2idx/get)
- Handle edge cases like nil items and empty file paths
- Add comprehensive test coverage for visual selection scenarios

Author: andresthor

dev-config.lua

@@ -23,7 +23,7 @@ return {
       "<leader>as",
       "<cmd>ClaudeCodeTreeAdd<cr>",
       desc = "Add file from tree",
-      ft = { "NvimTree", "neo-tree", "oil" },
+      ft = { "NvimTree", "neo-tree", "oil", "snacks_picker_list" }, -- snacks.explorer uses "snacks_picker_list" filetype
     },
 
     -- Development helpers

lua/claudecode/integrations.lua

@@ -265,9 +265,11 @@ end
 
 --- Get selected files from snacks.explorer
 --- Uses the picker API to get the current selection
+--- @param visual_start number|nil Start line of visual selection (optional)
+--- @param visual_end number|nil End line of visual selection (optional)
 --- @return table files List of file paths
 --- @return string|nil error Error message if operation failed
-function M._get_snacks_explorer_selection()
+function M._get_snacks_explorer_selection(visual_start, visual_end)
   local snacks_ok, snacks = pcall(require, "snacks")
   if not snacks_ok or not snacks.picker then
     return {}, "snacks.nvim not available"
@@ -287,14 +289,61 @@ function M._get_snacks_explorer_selection()
 
   local files = {}
 
-  -- Check if there are selected items
+  -- Helper function to extract file path from various item structures
+  local function extract_file_path(item)
+    if not item then
+      return nil
+    end
+    local file_path = item.file or item.path or (item.item and item.item.file) or (item.item and item.item.path)
+
+    -- Add trailing slash for directories
+    if file_path and file_path ~= "" and vim.fn.isdirectory(file_path) == 1 then
+      if not file_path:match("/$") then
+        file_path = file_path .. "/"
+      end
+    end
+
+    return file_path
+  end
+
+  -- Helper function to check if path is safe (not root-level)
+  local function is_safe_path(file_path)
+    if not file_path or file_path == "" then
+      return false
+    end
+    -- Not root-level file & this prevents selecting files like /etc/passwd, /usr/bin/vim, etc.
+    return not string.match(file_path, "^/[^/]*$")
+  end
+
+  -- Handle visual mode selection if range is provided
+  if visual_start and visual_end and explorer.list then
+    -- Process each line in the visual selection
+    for row = visual_start, visual_end do
+      -- Convert row to picker index
+      local idx = explorer.list:row2idx(row)
+      if idx then
+        -- Get the item at this index
+        local item = explorer.list:get(idx)
+        if item then
+          local file_path = extract_file_path(item)
+          if file_path and file_path ~= "" and is_safe_path(file_path) then
+            table.insert(files, file_path)
+          end
+        end
+      end
+    end
+    if #files > 0 then
+      return files, nil
+    end
+  end
+
+  -- Check if there are selected items (using toggle selection)
   local selected = explorer:selected({ fallback = false })
   if selected and #selected > 0 then
     -- Process selected items
     for _, item in ipairs(selected) do
-      -- Try different possible fields for file path
-      local file_path = item.file or item.path or (item.item and item.item.file) or (item.item and item.item.path)
-      if file_path and file_path ~= "" then
+      local file_path = extract_file_path(item)
+      if file_path and file_path ~= "" and is_safe_path(file_path) then
         table.insert(files, file_path)
       end
     end
@@ -306,13 +355,13 @@ function M._get_snacks_explorer_selection()
   -- Fall back to current item under cursor
   local current = explorer:current({ resolve = true })
   if current then
-    -- Try different possible fields for file path
-    local file_path = current.file
-      or current.path
-      or (current.item and current.item.file)
-      or (current.item and current.item.path)
+    local file_path = extract_file_path(current)
     if file_path and file_path ~= "" then
-      return { file_path }, nil
+      if is_safe_path(file_path) then
+        return { file_path }, nil
+      else
+        return {}, "Cannot add root-level file. Please select a file in a subdirectory."
+      end
     end
   end
 

lua/claudecode/visual_commands.lua

@@ -392,10 +392,9 @@ function M.get_files_from_visual_selection(visual_data)
       end
     end
   elseif tree_type == "snacks-explorer" then
-    -- For snacks.explorer, we need to handle visual selection differently
-    -- since it's a picker and doesn't have a traditional tree structure
+    -- For snacks.explorer, pass the visual range to handle multi-selection
     local integrations = require("claudecode.integrations")
-    local selected_files, error = integrations._get_snacks_explorer_selection()
+    local selected_files, error = integrations._get_snacks_explorer_selection(start_pos, end_pos)
 
     if not error and selected_files and #selected_files > 0 then
       for _, file in ipairs(selected_files) do

tests/unit/snacks_explorer_spec.lua

@@ -186,6 +186,162 @@ describe("snacks.explorer integration", function()
 
       package.loaded["snacks"] = nil
     end)
+
+    it("should handle visual mode selection with range parameters", function()
+      -- Mock snacks module with explorer picker that has list
+      local mock_list = {
+        row2idx = function(self, row)
+          return row -- Simple 1:1 mapping for test
+        end,
+        get = function(self, idx)
+          local items = {
+            [1] = { file = "/path/to/file1.lua" },
+            [2] = { file = "/path/to/file2.lua" },
+            [3] = { file = "/path/to/file3.lua" },
+            [4] = { file = "/path/to/file4.lua" },
+            [5] = { file = "/path/to/file5.lua" },
+          }
+          return items[idx]
+        end,
+      }
+
+      local mock_explorer = {
+        list = mock_list,
+        selected = function(self, opts)
+          return {} -- No marked selection
+        end,
+        current = function(self, opts)
+          return { file = "/path/to/current.lua" }
+        end,
+      }
+
+      local mock_snacks = {
+        picker = {
+          get = function(opts)
+            if opts.source == "explorer" then
+              return { mock_explorer }
+            end
+            return {}
+          end,
+        },
+      }
+
+      package.loaded["snacks"] = mock_snacks
+
+      -- Test visual selection from lines 2 to 4
+      local files, err = integrations._get_snacks_explorer_selection(2, 4)
+      assert.is_nil(err)
+      assert.are.same({
+        "/path/to/file2.lua",
+        "/path/to/file3.lua",
+        "/path/to/file4.lua",
+      }, files)
+
+      package.loaded["snacks"] = nil
+    end)
+
+    it("should handle visual mode with missing items and empty paths", function()
+      -- Mock snacks module with some problematic items
+      local mock_list = {
+        row2idx = function(self, row)
+          -- Some rows don't have corresponding indices
+          if row == 3 then
+            return nil
+          end
+          return row
+        end,
+        get = function(self, idx)
+          local items = {
+            [1] = { file = "" }, -- Empty path
+            [2] = { file = "/valid/file.lua" },
+            [4] = { path = "/path/based/file.lua" }, -- Using path field
+            [5] = nil, -- nil item
+          }
+          return items[idx]
+        end,
+      }
+
+      local mock_explorer = {
+        list = mock_list,
+        selected = function(self, opts)
+          return {}
+        end,
+        current = function(self, opts)
+          return { file = "/current.lua" }
+        end,
+      }
+
+      local mock_snacks = {
+        picker = {
+          get = function(opts)
+            if opts.source == "explorer" then
+              return { mock_explorer }
+            end
+            return {}
+          end,
+        },
+      }
+
+      package.loaded["snacks"] = mock_snacks
+
+      -- Test visual selection from lines 1 to 5
+      local files, err = integrations._get_snacks_explorer_selection(1, 5)
+      assert.is_nil(err)
+      -- Should only get the valid files
+      assert.are.same({
+        "/valid/file.lua",
+        "/path/based/file.lua",
+      }, files)
+
+      package.loaded["snacks"] = nil
+    end)
+
+    it("should add trailing slashes to directories", function()
+      -- Mock vim.fn.isdirectory to return true for directory paths
+      local original_isdirectory = vim.fn.isdirectory
+      vim.fn.isdirectory = function(path)
+        return path:match("/directory") and 1 or 0
+      end
+
+      -- Mock snacks module with directory items
+      local mock_explorer = {
+        selected = function(self, opts)
+          return {
+            { file = "/path/to/file.lua" }, -- file
+            { file = "/path/to/directory" }, -- directory (no trailing slash)
+            { file = "/path/to/another_directory/" }, -- directory (already has slash)
+          }
+        end,
+        current = function(self, opts)
+          return { file = "/current/directory" } -- directory
+        end,
+      }
+
+      local mock_snacks = {
+        picker = {
+          get = function(opts)
+            if opts.source == "explorer" then
+              return { mock_explorer }
+            end
+            return {}
+          end,
+        },
+      }
+
+      package.loaded["snacks"] = mock_snacks
+
+      local files, err = integrations._get_snacks_explorer_selection()
+      assert.is_nil(err)
+      assert.are.same({
+        "/path/to/file.lua", -- file unchanged
+        "/path/to/directory/", -- directory with added slash
+        "/path/to/another_directory/", -- directory with existing slash unchanged
+      }, files)
+
+      -- Restore original function
+      vim.fn.isdirectory = original_isdirectory
+      package.loaded["snacks"] = nil
+    end)
   end)
 
   describe("get_selected_files_from_tree", function()
@@ -222,4 +378,4 @@ describe("snacks.explorer integration", function()
       package.loaded["snacks"] = nil
     end)
   end)
-end)
+end)