chore: import upstream snapshot with attribution

tests/grep_jump_file_spec.lua

@@ -0,0 +1,137 @@
+---@diagnostic disable: undefined-field, missing-fields
+-- Integration tests for grep mode file-group jump shortcuts.
+local picker_ui
+local state_mod
+
+local plugin_dir = vim.fn.fnamemodify(vim.fn.resolve(debug.getinfo(1, 'S').source:sub(2)), ':h:h')
+
+local function make_item(path, line, col)
+  return { relative_path = path, line_number = line, col = col, line_content = '' }
+end
+
+local function reset_state(items, cursor)
+  local S = state_mod.state
+  S.active = true
+  S.mode = 'grep'
+  S.filtered_items = items
+  S.items = items
+  S.cursor = cursor or 1
+  S.pagination = S.pagination or {}
+  S.pagination.page_size = #items
+  S.pagination.page_index = 0
+  S.pagination.total_matched = #items
+  S.pagination.grep_file_offsets = { 0 }
+  S.pagination.grep_next_file_offset = 0
+end
+
+local stubs_installed = false
+local function install_stubs()
+  if stubs_installed then return end
+  -- Mock UI updates called by submodules
+  picker_ui.render_after_cursor_move = function() return true end
+  picker_ui.update_status = function() end
+  picker_ui.update_preview_debounced = function() end
+  stubs_installed = true
+end
+
+describe('grep_jump_to_next_file / grep_jump_to_prev_file', function()
+  before_each(function()
+    vim.g.fff = {}
+
+    local fff_rust = require('fff.rust')
+    local file_picker = require('fff.file_picker')
+
+    -- Initialize core components and background worker threads
+    file_picker.setup()
+    fff_rust.init_file_picker(plugin_dir)
+
+    -- Resolve to the correct coordinator path inside the submodules directory
+    picker_ui = require('fff.picker_ui.picker_ui')
+    state_mod = require('fff.picker_ui.picker_ui_state')
+
+    install_stubs()
+  end)
+
+  after_each(function()
+    local fff_rust = require('fff.rust')
+    pcall(fff_rust.stop_background_monitor)
+    pcall(fff_rust.cleanup_file_picker)
+    vim.g.fff = nil
+  end)
+
+  it('jumps to first match of the next file group', function()
+    local items = {
+      make_item('a.lua', 1, 1),
+      make_item('a.lua', 5, 3),
+      make_item('a.lua', 9, 1),
+      make_item('b.lua', 2, 1),
+      make_item('b.lua', 7, 1),
+      make_item('c.lua', 4, 2),
+    }
+    reset_state(items, 1)
+
+    picker_ui.grep_jump_to_next_file()
+    assert.are.equal(4, state_mod.state.cursor)
+
+    picker_ui.grep_jump_to_next_file()
+    assert.are.equal(6, state_mod.state.cursor)
+  end)
+
+  it('jumps to first match of the previous file group', function()
+    local items = {
+      make_item('a.lua', 1, 1),
+      make_item('a.lua', 5, 3),
+      make_item('b.lua', 2, 1),
+      make_item('b.lua', 7, 1),
+      make_item('c.lua', 4, 2),
+    }
+    reset_state(items, 5)
+
+    picker_ui.grep_jump_to_prev_file()
+    assert.are.equal(3, state_mod.state.cursor)
+
+    picker_ui.grep_jump_to_prev_file()
+    assert.are.equal(1, state_mod.state.cursor)
+  end)
+
+  it('is a no-op when not in grep mode', function()
+    local items = { make_item('a.lua', 1, 1), make_item('b.lua', 1, 1) }
+    reset_state(items, 1)
+    state_mod.state.mode = nil
+
+    picker_ui.grep_jump_to_next_file()
+    assert.are.equal(1, state_mod.state.cursor)
+  end)
+
+  it('loads next page when no later file group exists on current page', function()
+    local page1 = {
+      make_item('a.lua', 1, 1),
+      make_item('a.lua', 2, 1),
+    }
+    local page2 = {
+      make_item('b.lua', 1, 1),
+      make_item('b.lua', 4, 1),
+    }
+    reset_state(page1, 2)
+    state_mod.state.pagination.grep_next_file_offset = 1
+
+    local called = false
+    local original_load_next = picker_ui.load_next_page
+
+    picker_ui.load_next_page = function()
+      called = true
+      state_mod.state.filtered_items = page2
+      state_mod.state.items = page2
+      state_mod.state.cursor = 1
+      state_mod.state.pagination.page_index = 1
+      return true
+    end
+
+    picker_ui.grep_jump_to_next_file()
+    assert.is_true(called, 'expected load_next_page to be invoked')
+    assert.are.equal(1, state_mod.state.cursor)
+    assert.are.equal('b.lua', state_mod.state.filtered_items[state_mod.state.cursor].relative_path)
+
+    picker_ui.load_next_page = original_load_next
+  end)
+end)