text_tests.lua

   1 -- major tests for text editing flows
   2 -- Arguably this should be called edit_tests.lua,
   3 -- but that would mess up the git blame at this point.
   4
   5 function test_initial_state()
   6   App.screen.init{width=120, height=60}
   7   Editor_state = edit.initialize_test_state()
   8   Editor_state.lines = load_array{}
   9   Text.redraw_all(Editor_state)
  10   edit.draw(Editor_state)
  11   check_eq(#Editor_state.lines, 1, '#lines')
  12   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
  13   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
  14   check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
  15   check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
  16 end
  17
  18 function test_click_to_create_drawing()
  19   App.screen.init{width=120, height=60}
  20   Editor_state = edit.initialize_test_state()
  21   Editor_state.lines = load_array{}
  22   Text.redraw_all(Editor_state)
  23   edit.draw(Editor_state)
  24   edit.run_after_mouse_click(Editor_state, 8,Editor_state.top+8, 1)
  25   -- cursor skips drawing to always remain on text
  26   check_eq(#Editor_state.lines, 2, '#lines')
  27   check_eq(Editor_state.cursor1.line, 2, 'cursor')
  28 end
  29
  30 function test_backspace_to_delete_drawing()
  31   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
  32   App.screen.init{width=120, height=60}
  33   Editor_state = edit.initialize_test_state()
  34   Editor_state.lines = load_array{'```lines', '```', ''}
  35   Text.redraw_all(Editor_state)
  36   -- cursor is on text as always (outside tests this will get initialized correctly)
  37   Editor_state.cursor1.line = 2
  38   -- backspacing deletes the drawing
  39   edit.run_after_keychord(Editor_state, 'backspace')
  40   check_eq(#Editor_state.lines, 1, '#lines')
  41   check_eq(Editor_state.cursor1.line, 1, 'cursor')
  42 end
  43
  44 function test_backspace_from_start_of_final_line()
  45   -- display final line of text with cursor at start of it
  46   App.screen.init{width=120, height=60}
  47   Editor_state = edit.initialize_test_state()
  48   Editor_state.lines = load_array{'abc', 'def'}
  49   Editor_state.screen_top1 = {line=2, pos=1}
  50   Editor_state.cursor1 = {line=2, pos=1}
  51   Text.redraw_all(Editor_state)
  52   -- backspace scrolls up
  53   edit.run_after_keychord(Editor_state, 'backspace')
  54   check_eq(#Editor_state.lines, 1, '#lines')
  55   check_eq(Editor_state.cursor1.line, 1, 'cursor')
  56   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
  57 end
  58
  59 function test_insert_first_character()
  60   App.screen.init{width=120, height=60}
  61   Editor_state = edit.initialize_test_state()
  62   Editor_state.lines = load_array{}
  63   Text.redraw_all(Editor_state)
  64   edit.draw(Editor_state)
  65   edit.run_after_text_input(Editor_state, 'a')
  66   local y = Editor_state.top
  67   App.screen.check(y, 'a', 'screen:1')
  68 end
  69
  70 function test_press_ctrl()
  71   -- press ctrl while the cursor is on text
  72   App.screen.init{width=50, height=80}
  73   Editor_state = edit.initialize_test_state()
  74   Editor_state.lines = load_array{''}
  75   Text.redraw_all(Editor_state)
  76   Editor_state.cursor1 = {line=1, pos=1}
  77   Editor_state.screen_top1 = {line=1, pos=1}
  78   Editor_state.screen_bottom1 = {}
  79   edit.run_after_keychord(Editor_state, 'C-m')
  80 end
  81
  82 function test_move_left()
  83   App.screen.init{width=120, height=60}
  84   Editor_state = edit.initialize_test_state()
  85   Editor_state.lines = load_array{'a'}
  86   Text.redraw_all(Editor_state)
  87   Editor_state.cursor1 = {line=1, pos=2}
  88   edit.draw(Editor_state)
  89   edit.run_after_keychord(Editor_state, 'left')
  90   check_eq(Editor_state.cursor1.pos, 1, 'check')
  91 end
  92
  93 function test_move_right()
  94   App.screen.init{width=120, height=60}
  95   Editor_state = edit.initialize_test_state()
  96   Editor_state.lines = load_array{'a'}
  97   Text.redraw_all(Editor_state)
  98   Editor_state.cursor1 = {line=1, pos=1}
  99   edit.draw(Editor_state)
 100   edit.run_after_keychord(Editor_state, 'right')
 101   check_eq(Editor_state.cursor1.pos, 2, 'check')
 102 end
 103
 104 function test_move_left_to_previous_line()
 105   App.screen.init{width=120, height=60}
 106   Editor_state = edit.initialize_test_state()
 107   Editor_state.lines = load_array{'abc', 'def'}
 108   Text.redraw_all(Editor_state)
 109   Editor_state.cursor1 = {line=2, pos=1}
 110   edit.draw(Editor_state)
 111   edit.run_after_keychord(Editor_state, 'left')
 112   check_eq(Editor_state.cursor1.line, 1, 'line')
 113   check_eq(Editor_state.cursor1.pos, 4, 'pos')  -- past end of line
 114 end
 115
 116 function test_move_right_to_next_line()
 117   App.screen.init{width=120, height=60}
 118   Editor_state = edit.initialize_test_state()
 119   Editor_state.lines = load_array{'abc', 'def'}
 120   Text.redraw_all(Editor_state)
 121   Editor_state.cursor1 = {line=1, pos=4}  -- past end of line
 122   edit.draw(Editor_state)
 123   edit.run_after_keychord(Editor_state, 'right')
 124   check_eq(Editor_state.cursor1.line, 2, 'line')
 125   check_eq(Editor_state.cursor1.pos, 1, 'pos')
 126 end
 127
 128 function test_move_to_start_of_word()
 129   App.screen.init{width=120, height=60}
 130   Editor_state = edit.initialize_test_state()
 131   Editor_state.lines = load_array{'abc'}
 132   Text.redraw_all(Editor_state)
 133   Editor_state.cursor1 = {line=1, pos=3}
 134   edit.draw(Editor_state)
 135   edit.run_after_keychord(Editor_state, 'M-left')
 136   check_eq(Editor_state.cursor1.pos, 1, 'check')
 137 end
 138
 139 function test_move_to_start_of_previous_word()
 140   App.screen.init{width=120, height=60}
 141   Editor_state = edit.initialize_test_state()
 142   Editor_state.lines = load_array{'abc def'}
 143   Text.redraw_all(Editor_state)
 144   Editor_state.cursor1 = {line=1, pos=4}  -- at the space between words
 145   edit.draw(Editor_state)
 146   edit.run_after_keychord(Editor_state, 'M-left')
 147   check_eq(Editor_state.cursor1.pos, 1, 'check')
 148 end
 149
 150 function test_skip_to_previous_word()
 151   App.screen.init{width=120, height=60}
 152   Editor_state = edit.initialize_test_state()
 153   Editor_state.lines = load_array{'abc def'}
 154   Text.redraw_all(Editor_state)
 155   Editor_state.cursor1 = {line=1, pos=5}  -- at the start of second word
 156   edit.draw(Editor_state)
 157   edit.run_after_keychord(Editor_state, 'M-left')
 158   check_eq(Editor_state.cursor1.pos, 1, 'check')
 159 end
 160
 161 function test_skip_past_tab_to_previous_word()
 162   App.screen.init{width=120, height=60}
 163   Editor_state = edit.initialize_test_state()
 164   Editor_state.lines = load_array{'abc def\tghi'}
 165   Text.redraw_all(Editor_state)
 166   Editor_state.cursor1 = {line=1, pos=10}  -- within third word
 167   edit.draw(Editor_state)
 168   edit.run_after_keychord(Editor_state, 'M-left')
 169   check_eq(Editor_state.cursor1.pos, 9, 'check')
 170 end
 171
 172 function test_skip_multiple_spaces_to_previous_word()
 173   App.screen.init{width=120, height=60}
 174   Editor_state = edit.initialize_test_state()
 175   Editor_state.lines = load_array{'abc  def'}
 176   Text.redraw_all(Editor_state)
 177   Editor_state.cursor1 = {line=1, pos=6}  -- at the start of second word
 178   edit.draw(Editor_state)
 179   edit.run_after_keychord(Editor_state, 'M-left')
 180   check_eq(Editor_state.cursor1.pos, 1, 'check')
 181 end
 182
 183 function test_move_to_start_of_word_on_previous_line()
 184   App.screen.init{width=120, height=60}
 185   Editor_state = edit.initialize_test_state()
 186   Editor_state.lines = load_array{'abc def', 'ghi'}
 187   Text.redraw_all(Editor_state)
 188   Editor_state.cursor1 = {line=2, pos=1}
 189   edit.draw(Editor_state)
 190   edit.run_after_keychord(Editor_state, 'M-left')
 191   check_eq(Editor_state.cursor1.line, 1, 'line')
 192   check_eq(Editor_state.cursor1.pos, 5, 'pos')
 193 end
 194
 195 function test_move_past_end_of_word()
 196   App.screen.init{width=120, height=60}
 197   Editor_state = edit.initialize_test_state()
 198   Editor_state.lines = load_array{'abc def'}
 199   Text.redraw_all(Editor_state)
 200   Editor_state.cursor1 = {line=1, pos=1}
 201   edit.draw(Editor_state)
 202   edit.run_after_keychord(Editor_state, 'M-right')
 203   check_eq(Editor_state.cursor1.pos, 4, 'check')
 204 end
 205
 206 function test_skip_to_next_word()
 207   App.screen.init{width=120, height=60}
 208   Editor_state = edit.initialize_test_state()
 209   Editor_state.lines = load_array{'abc def'}
 210   Text.redraw_all(Editor_state)
 211   Editor_state.cursor1 = {line=1, pos=4}  -- at the space between words
 212   edit.draw(Editor_state)
 213   edit.run_after_keychord(Editor_state, 'M-right')
 214   check_eq(Editor_state.cursor1.pos, 8, 'check')
 215 end
 216
 217 function test_skip_past_tab_to_next_word()
 218   App.screen.init{width=120, height=60}
 219   Editor_state = edit.initialize_test_state()
 220   Editor_state.lines = load_array{'abc\tdef'}
 221   Text.redraw_all(Editor_state)
 222   Editor_state.cursor1 = {line=1, pos=1}  -- at the space between words
 223   edit.draw(Editor_state)
 224   edit.run_after_keychord(Editor_state, 'M-right')
 225   check_eq(Editor_state.cursor1.pos, 4, 'check')
 226 end
 227
 228 function test_skip_multiple_spaces_to_next_word()
 229   App.screen.init{width=120, height=60}
 230   Editor_state = edit.initialize_test_state()
 231   Editor_state.lines = load_array{'abc  def'}
 232   Text.redraw_all(Editor_state)
 233   Editor_state.cursor1 = {line=1, pos=4}  -- at the start of second word
 234   edit.draw(Editor_state)
 235   edit.run_after_keychord(Editor_state, 'M-right')
 236   check_eq(Editor_state.cursor1.pos, 9, 'check')
 237 end
 238
 239 function test_move_past_end_of_word_on_next_line()
 240   App.screen.init{width=120, height=60}
 241   Editor_state = edit.initialize_test_state()
 242   Editor_state.lines = load_array{'abc def', 'ghi'}
 243   Text.redraw_all(Editor_state)
 244   Editor_state.cursor1 = {line=1, pos=8}
 245   edit.draw(Editor_state)
 246   edit.run_after_keychord(Editor_state, 'M-right')
 247   check_eq(Editor_state.cursor1.line, 2, 'line')
 248   check_eq(Editor_state.cursor1.pos, 4, 'pos')
 249 end
 250
 251 function test_click_moves_cursor()
 252   App.screen.init{width=50, height=60}
 253   Editor_state = edit.initialize_test_state()
 254   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
 255   Text.redraw_all(Editor_state)
 256   Editor_state.cursor1 = {line=1, pos=1}
 257   Editor_state.screen_top1 = {line=1, pos=1}
 258   Editor_state.screen_bottom1 = {}
 259   Editor_state.selection1 = {}
 260   edit.draw(Editor_state)  -- populate line_cache.starty for each line Editor_state.line_cache
 261   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 262   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 263   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 264   -- selection is empty to avoid perturbing future edits
 265   check_nil(Editor_state.selection1.line, 'selection:line')
 266   check_nil(Editor_state.selection1.pos, 'selection:pos')
 267 end
 268
 269 function test_click_to_left_of_line()
 270   -- display a line with the cursor in the middle
 271   App.screen.init{width=50, height=80}
 272   Editor_state = edit.initialize_test_state()
 273   Editor_state.lines = load_array{'abc'}
 274   Text.redraw_all(Editor_state)
 275   Editor_state.cursor1 = {line=1, pos=3}
 276   Editor_state.screen_top1 = {line=1, pos=1}
 277   Editor_state.screen_bottom1 = {}
 278   -- click to the left of the line
 279   edit.draw(Editor_state)
 280   edit.run_after_mouse_click(Editor_state, Editor_state.left-4,Editor_state.top+5, 1)
 281   -- cursor moves to start of line
 282   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 283   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
 284   check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 285 end
 286
 287 function test_click_takes_margins_into_account()
 288   -- display two lines with cursor on one of them
 289   App.screen.init{width=100, height=80}
 290   Editor_state = edit.initialize_test_state()
 291   Editor_state.left = 50  -- occupy only right side of screen
 292   Editor_state.lines = load_array{'abc', 'def'}
 293   Text.redraw_all(Editor_state)
 294   Editor_state.cursor1 = {line=2, pos=1}
 295   Editor_state.screen_top1 = {line=1, pos=1}
 296   Editor_state.screen_bottom1 = {}
 297   -- click on the other line
 298   edit.draw(Editor_state)
 299   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 300   -- cursor moves
 301   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 302   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 303   check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 304 end
 305
 306 function test_click_on_empty_line()
 307   -- display two lines with the first one empty
 308   App.screen.init{width=50, height=80}
 309   Editor_state = edit.initialize_test_state()
 310   Editor_state.lines = load_array{'', 'def'}
 311   Text.redraw_all(Editor_state)
 312   Editor_state.cursor1 = {line=2, pos=1}
 313   Editor_state.screen_top1 = {line=1, pos=1}
 314   Editor_state.screen_bottom1 = {}
 315   -- click on the empty line
 316   edit.draw(Editor_state)
 317   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 318   -- cursor moves
 319   check_eq(Editor_state.cursor1.line, 1, 'cursor')
 320 end
 321
 322 function test_draw_text()
 323   App.screen.init{width=120, height=60}
 324   Editor_state = edit.initialize_test_state()
 325   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
 326   Text.redraw_all(Editor_state)
 327   Editor_state.cursor1 = {line=1, pos=1}
 328   Editor_state.screen_top1 = {line=1, pos=1}
 329   Editor_state.screen_bottom1 = {}
 330   edit.draw(Editor_state)
 331   local y = Editor_state.top
 332   App.screen.check(y, 'abc', 'screen:1')
 333   y = y + Editor_state.line_height
 334   App.screen.check(y, 'def', 'screen:2')
 335   y = y + Editor_state.line_height
 336   App.screen.check(y, 'ghi', 'screen:3')
 337 end
 338
 339 function test_draw_wrapping_text()
 340   App.screen.init{width=50, height=60}
 341   Editor_state = edit.initialize_test_state()
 342   Editor_state.lines = load_array{'abc', 'defgh', 'xyz'}
 343   Text.redraw_all(Editor_state)
 344   Editor_state.cursor1 = {line=1, pos=1}
 345   Editor_state.screen_top1 = {line=1, pos=1}
 346   Editor_state.screen_bottom1 = {}
 347   edit.draw(Editor_state)
 348   local y = Editor_state.top
 349   App.screen.check(y, 'abc', 'screen:1')
 350   y = y + Editor_state.line_height
 351   App.screen.check(y, 'de', 'screen:2')
 352   y = y + Editor_state.line_height
 353   App.screen.check(y, 'fgh', 'screen:3')
 354 end
 355
 356 function test_draw_word_wrapping_text()
 357   App.screen.init{width=60, height=60}
 358   Editor_state = edit.initialize_test_state()
 359   Editor_state.lines = load_array{'abc def ghi', 'jkl'}
 360   Text.redraw_all(Editor_state)
 361   Editor_state.cursor1 = {line=1, pos=1}
 362   Editor_state.screen_top1 = {line=1, pos=1}
 363   Editor_state.screen_bottom1 = {}
 364   edit.draw(Editor_state)
 365   local y = Editor_state.top
 366   App.screen.check(y, 'abc ', 'screen:1')
 367   y = y + Editor_state.line_height
 368   App.screen.check(y, 'def ', 'screen:2')
 369   y = y + Editor_state.line_height
 370   App.screen.check(y, 'ghi', 'screen:3')
 371 end
 372
 373 function test_click_on_wrapping_line()
 374   -- display two screen lines with cursor on one of them
 375   App.screen.init{width=50, height=80}
 376   Editor_state = edit.initialize_test_state()
 377   Editor_state.lines = load_array{'abc def ghi jkl mno pqr stu'}
 378   Text.redraw_all(Editor_state)
 379   Editor_state.cursor1 = {line=1, pos=20}
 380   Editor_state.screen_top1 = {line=1, pos=1}
 381   Editor_state.screen_bottom1 = {}
 382   -- click on the other line
 383   edit.draw(Editor_state)
 384   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 385   -- cursor moves
 386   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 387   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 388   check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 389 end
 390
 391 function test_click_on_wrapping_line_takes_margins_into_account()
 392   -- display two screen lines with cursor on one of them
 393   App.screen.init{width=100, height=80}
 394   Editor_state = edit.initialize_test_state()
 395   Editor_state.left = 50  -- occupy only right side of screen
 396   Editor_state.lines = load_array{'abc def ghi jkl mno pqr stu'}
 397   Text.redraw_all(Editor_state)
 398   Editor_state.cursor1 = {line=1, pos=20}
 399   Editor_state.screen_top1 = {line=1, pos=1}
 400   Editor_state.screen_bottom1 = {}
 401   -- click on the other line
 402   edit.draw(Editor_state)
 403   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 404   -- cursor moves
 405   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 406   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 407   check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 408 end
 409
 410 function test_draw_text_wrapping_within_word()
 411   -- arrange a screen line that needs to be split within a word
 412   App.screen.init{width=60, height=60}
 413   Editor_state = edit.initialize_test_state()
 414   Editor_state.lines = load_array{'abcd e fghijk', 'xyz'}
 415   Text.redraw_all(Editor_state)
 416   Editor_state.cursor1 = {line=1, pos=1}
 417   Editor_state.screen_top1 = {line=1, pos=1}
 418   Editor_state.screen_bottom1 = {}
 419   edit.draw(Editor_state)
 420   local y = Editor_state.top
 421   App.screen.check(y, 'abcd ', 'screen:1')
 422   y = y + Editor_state.line_height
 423   App.screen.check(y, 'e fgh', 'screen:2')
 424   y = y + Editor_state.line_height
 425   App.screen.check(y, 'ijk', 'screen:3')
 426 end
 427
 428 function test_draw_wrapping_text_containing_non_ascii()
 429   -- draw a long line containing non-ASCII
 430   App.screen.init{width=60, height=60}
 431   Editor_state = edit.initialize_test_state()
 432   Editor_state.lines = load_array{'madam I’m adam', 'xyz'}  -- notice the non-ASCII apostrophe
 433   Text.redraw_all(Editor_state)
 434   Editor_state.cursor1 = {line=1, pos=1}
 435   Editor_state.screen_top1 = {line=1, pos=1}
 436   Editor_state.screen_bottom1 = {}
 437   edit.draw(Editor_state)
 438   local y = Editor_state.top
 439   App.screen.check(y, 'mad', 'screen:1')
 440   y = y + Editor_state.line_height
 441   App.screen.check(y, 'am I', 'screen:2')
 442   y = y + Editor_state.line_height
 443   App.screen.check(y, '’m a', 'screen:3')
 444 end
 445
 446 function test_click_past_end_of_screen_line()
 447   -- display a wrapping line
 448   App.screen.init{width=75, height=80}
 449   Editor_state = edit.initialize_test_state()
 450                                --  12345678901234
 451   Editor_state.lines = load_array{"madam I'm adam"}
 452   Text.redraw_all(Editor_state)
 453   Editor_state.cursor1 = {line=1, pos=1}
 454   Editor_state.screen_top1 = {line=1, pos=1}
 455   Editor_state.screen_bottom1 = {}
 456   edit.draw(Editor_state)
 457   local y = Editor_state.top
 458   App.screen.check(y, 'madam ', 'baseline/screen:1')
 459   y = y + Editor_state.line_height
 460   App.screen.check(y, "I'm ad", 'baseline/screen:2')
 461   y = y + Editor_state.line_height
 462   -- click past end of second screen line
 463   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
 464   -- cursor moves to end of screen line
 465   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 466   check_eq(Editor_state.cursor1.pos, 12, 'cursor:pos')
 467 end
 468
 469 function test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen()
 470   -- display a wrapping line from its second screen line
 471   App.screen.init{width=75, height=80}
 472   Editor_state = edit.initialize_test_state()
 473                                --  12345678901234
 474   Editor_state.lines = load_array{"madam I'm adam"}
 475   Text.redraw_all(Editor_state)
 476   Editor_state.cursor1 = {line=1, pos=8}
 477   Editor_state.screen_top1 = {line=1, pos=7}
 478   Editor_state.screen_bottom1 = {}
 479   edit.draw(Editor_state)
 480   local y = Editor_state.top
 481   App.screen.check(y, "I'm ad", 'baseline/screen:2')
 482   y = y + Editor_state.line_height
 483   -- click past end of second screen line
 484   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
 485   -- cursor moves to end of screen line
 486   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 487   check_eq(Editor_state.cursor1.pos, 12, 'cursor:pos')
 488 end
 489
 490 function test_click_past_end_of_wrapping_line()
 491   -- display a wrapping line
 492   App.screen.init{width=75, height=80}
 493   Editor_state = edit.initialize_test_state()
 494                                --  12345678901234
 495   Editor_state.lines = load_array{"madam I'm adam"}
 496   Text.redraw_all(Editor_state)
 497   Editor_state.cursor1 = {line=1, pos=1}
 498   Editor_state.screen_top1 = {line=1, pos=1}
 499   Editor_state.screen_bottom1 = {}
 500   edit.draw(Editor_state)
 501   local y = Editor_state.top
 502   App.screen.check(y, 'madam ', 'baseline/screen:1')
 503   y = y + Editor_state.line_height
 504   App.screen.check(y, "I'm ad", 'baseline/screen:2')
 505   y = y + Editor_state.line_height
 506   App.screen.check(y, 'am', 'baseline/screen:3')
 507   y = y + Editor_state.line_height
 508   -- click past the end of it
 509   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
 510   -- cursor moves to end of line
 511   check_eq(Editor_state.cursor1.pos, 15, 'cursor')  -- one more than the number of UTF-8 code-points
 512 end
 513
 514 function test_click_past_end_of_wrapping_line_containing_non_ascii()
 515   -- display a wrapping line containing non-ASCII
 516   App.screen.init{width=75, height=80}
 517   Editor_state = edit.initialize_test_state()
 518                                --  12345678901234
 519   Editor_state.lines = load_array{'madam I’m adam'}  -- notice the non-ASCII apostrophe
 520   Text.redraw_all(Editor_state)
 521   Editor_state.cursor1 = {line=1, pos=1}
 522   Editor_state.screen_top1 = {line=1, pos=1}
 523   Editor_state.screen_bottom1 = {}
 524   edit.draw(Editor_state)
 525   local y = Editor_state.top
 526   App.screen.check(y, 'madam ', 'baseline/screen:1')
 527   y = y + Editor_state.line_height
 528   App.screen.check(y, 'I’m ad', 'baseline/screen:2')
 529   y = y + Editor_state.line_height
 530   App.screen.check(y, 'am', 'baseline/screen:3')
 531   y = y + Editor_state.line_height
 532   -- click past the end of it
 533   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
 534   -- cursor moves to end of line
 535   check_eq(Editor_state.cursor1.pos, 15, 'cursor')  -- one more than the number of UTF-8 code-points
 536 end
 537
 538 function test_click_past_end_of_word_wrapping_line()
 539   -- display a long line wrapping at a word boundary on a screen of more realistic length
 540   App.screen.init{width=160, height=80}
 541   Editor_state = edit.initialize_test_state()
 542                                 -- 0        1         2
 543                                 -- 123456789012345678901
 544   Editor_state.lines = load_array{'the quick brown fox jumped over the lazy dog'}
 545   Text.redraw_all(Editor_state)
 546   Editor_state.cursor1 = {line=1, pos=1}
 547   Editor_state.screen_top1 = {line=1, pos=1}
 548   Editor_state.screen_bottom1 = {}
 549   edit.draw(Editor_state)
 550   local y = Editor_state.top
 551   App.screen.check(y, 'the quick brown fox ', 'baseline/screen:1')
 552   y = y + Editor_state.line_height
 553   -- click past the end of the screen line
 554   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
 555   -- cursor moves to end of screen line
 556   check_eq(Editor_state.cursor1.pos, 20, 'cursor')
 557 end
 558
 559 function test_select_text()
 560   -- display a line of text
 561   App.screen.init{width=75, height=80}
 562   Editor_state = edit.initialize_test_state()
 563   Editor_state.lines = load_array{'abc def'}
 564   Text.redraw_all(Editor_state)
 565   Editor_state.cursor1 = {line=1, pos=1}
 566   Editor_state.screen_top1 = {line=1, pos=1}
 567   Editor_state.screen_bottom1 = {}
 568   edit.draw(Editor_state)
 569   -- select a letter
 570   App.fake_key_press('lshift')
 571   edit.run_after_keychord(Editor_state, 'S-right')
 572   App.fake_key_release('lshift')
 573   edit.key_release(Editor_state, 'lshift')
 574   -- selection persists even after shift is released
 575   check_eq(Editor_state.selection1.line, 1, 'selection:line')
 576   check_eq(Editor_state.selection1.pos, 1, 'selection:pos')
 577   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 578   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 579 end
 580
 581 function test_cursor_movement_without_shift_resets_selection()
 582   -- display a line of text with some part selected
 583   App.screen.init{width=75, height=80}
 584   Editor_state = edit.initialize_test_state()
 585   Editor_state.lines = load_array{'abc'}
 586   Text.redraw_all(Editor_state)
 587   Editor_state.cursor1 = {line=1, pos=1}
 588   Editor_state.selection1 = {line=1, pos=2}
 589   Editor_state.screen_top1 = {line=1, pos=1}
 590   Editor_state.screen_bottom1 = {}
 591   edit.draw(Editor_state)
 592   -- press an arrow key without shift
 593   edit.run_after_keychord(Editor_state, 'right')
 594   -- no change to data, selection is reset
 595   check_nil(Editor_state.selection1.line, 'check')
 596   check_eq(Editor_state.lines[1].data, 'abc', 'data')
 597 end
 598
 599 function test_edit_deletes_selection()
 600   -- display a line of text with some part selected
 601   App.screen.init{width=75, height=80}
 602   Editor_state = edit.initialize_test_state()
 603   Editor_state.lines = load_array{'abc'}
 604   Text.redraw_all(Editor_state)
 605   Editor_state.cursor1 = {line=1, pos=1}
 606   Editor_state.selection1 = {line=1, pos=2}
 607   Editor_state.screen_top1 = {line=1, pos=1}
 608   Editor_state.screen_bottom1 = {}
 609   edit.draw(Editor_state)
 610   -- press a key
 611   edit.run_after_text_input(Editor_state, 'x')
 612   -- selected text is deleted and replaced with the key
 613   check_eq(Editor_state.lines[1].data, 'xbc', 'check')
 614 end
 615
 616 function test_edit_with_shift_key_deletes_selection()
 617   -- display a line of text with some part selected
 618   App.screen.init{width=75, height=80}
 619   Editor_state = edit.initialize_test_state()
 620   Editor_state.lines = load_array{'abc'}
 621   Text.redraw_all(Editor_state)
 622   Editor_state.cursor1 = {line=1, pos=1}
 623   Editor_state.selection1 = {line=1, pos=2}
 624   Editor_state.screen_top1 = {line=1, pos=1}
 625   Editor_state.screen_bottom1 = {}
 626   edit.draw(Editor_state)
 627   -- mimic precise keypresses for a capital letter
 628   App.fake_key_press('lshift')
 629   edit.keychord_press(Editor_state, 'd', 'd')
 630   edit.text_input(Editor_state, 'D')
 631   edit.key_release(Editor_state, 'd')
 632   App.fake_key_release('lshift')
 633   -- selected text is deleted and replaced with the key
 634   check_nil(Editor_state.selection1.line, 'check')
 635   check_eq(Editor_state.lines[1].data, 'Dbc', 'data')
 636 end
 637
 638 function test_copy_does_not_reset_selection()
 639   -- display a line of text with a selection
 640   App.screen.init{width=75, height=80}
 641   Editor_state = edit.initialize_test_state()
 642   Editor_state.lines = load_array{'abc'}
 643   Text.redraw_all(Editor_state)
 644   Editor_state.cursor1 = {line=1, pos=1}
 645   Editor_state.selection1 = {line=1, pos=2}
 646   Editor_state.screen_top1 = {line=1, pos=1}
 647   Editor_state.screen_bottom1 = {}
 648   edit.draw(Editor_state)
 649   -- copy selection
 650   edit.run_after_keychord(Editor_state, 'C-c')
 651   check_eq(App.clipboard, 'a', 'clipboard')
 652   -- selection is reset since shift key is not pressed
 653   check(Editor_state.selection1.line, 'check')
 654 end
 655
 656 function test_cut()
 657   -- display a line of text with some part selected
 658   App.screen.init{width=75, height=80}
 659   Editor_state = edit.initialize_test_state()
 660   Editor_state.lines = load_array{'abc'}
 661   Text.redraw_all(Editor_state)
 662   Editor_state.cursor1 = {line=1, pos=1}
 663   Editor_state.selection1 = {line=1, pos=2}
 664   Editor_state.screen_top1 = {line=1, pos=1}
 665   Editor_state.screen_bottom1 = {}
 666   edit.draw(Editor_state)
 667   -- press a key
 668   edit.run_after_keychord(Editor_state, 'C-x')
 669   check_eq(App.clipboard, 'a', 'clipboard')
 670   -- selected text is deleted
 671   check_eq(Editor_state.lines[1].data, 'bc', 'data')
 672 end
 673
 674 function test_paste_replaces_selection()
 675   -- display a line of text with a selection
 676   App.screen.init{width=75, height=80}
 677   Editor_state = edit.initialize_test_state()
 678   Editor_state.lines = load_array{'abc', 'def'}
 679   Text.redraw_all(Editor_state)
 680   Editor_state.cursor1 = {line=2, pos=1}
 681   Editor_state.selection1 = {line=1, pos=1}
 682   Editor_state.screen_top1 = {line=1, pos=1}
 683   Editor_state.screen_bottom1 = {}
 684   edit.draw(Editor_state)
 685   -- set clipboard
 686   App.clipboard = 'xyz'
 687   -- paste selection
 688   edit.run_after_keychord(Editor_state, 'C-v')
 689   -- selection is reset since shift key is not pressed
 690   -- selection includes the newline, so it's also deleted
 691   check_eq(Editor_state.lines[1].data, 'xyzdef', 'check')
 692 end
 693
 694 function test_deleting_selection_may_scroll()
 695   -- display lines 2/3/4
 696   App.screen.init{width=120, height=60}
 697   Editor_state = edit.initialize_test_state()
 698   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
 699   Text.redraw_all(Editor_state)
 700   Editor_state.cursor1 = {line=3, pos=2}
 701   Editor_state.screen_top1 = {line=2, pos=1}
 702   Editor_state.screen_bottom1 = {}
 703   edit.draw(Editor_state)
 704   local y = Editor_state.top
 705   App.screen.check(y, 'def', 'baseline/screen:1')
 706   y = y + Editor_state.line_height
 707   App.screen.check(y, 'ghi', 'baseline/screen:2')
 708   y = y + Editor_state.line_height
 709   App.screen.check(y, 'jkl', 'baseline/screen:3')
 710   -- set up a selection starting above the currently displayed page
 711   Editor_state.selection1 = {line=1, pos=2}
 712   -- delete selection
 713   edit.run_after_keychord(Editor_state, 'backspace')
 714   -- page scrolls up
 715   check_eq(Editor_state.screen_top1.line, 1, 'check')
 716   check_eq(Editor_state.lines[1].data, 'ahi', 'data')
 717 end
 718
 719 function test_edit_wrapping_text()
 720   App.screen.init{width=50, height=60}
 721   Editor_state = edit.initialize_test_state()
 722   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
 723   Text.redraw_all(Editor_state)
 724   Editor_state.cursor1 = {line=2, pos=4}
 725   Editor_state.screen_top1 = {line=1, pos=1}
 726   Editor_state.screen_bottom1 = {}
 727   edit.draw(Editor_state)
 728   edit.run_after_text_input(Editor_state, 'g')
 729   local y = Editor_state.top
 730   App.screen.check(y, 'abc', 'screen:1')
 731   y = y + Editor_state.line_height
 732   App.screen.check(y, 'de', 'screen:2')
 733   y = y + Editor_state.line_height
 734   App.screen.check(y, 'fg', 'screen:3')
 735 end
 736
 737 function test_insert_newline()
 738   -- display a few lines
 739   App.screen.init{width=Editor_state.left+30, height=60}
 740   Editor_state = edit.initialize_test_state()
 741   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
 742   Text.redraw_all(Editor_state)
 743   Editor_state.cursor1 = {line=1, pos=2}
 744   Editor_state.screen_top1 = {line=1, pos=1}
 745   Editor_state.screen_bottom1 = {}
 746   edit.draw(Editor_state)
 747   local y = Editor_state.top
 748   App.screen.check(y, 'abc', 'baseline/screen:1')
 749   y = y + Editor_state.line_height
 750   App.screen.check(y, 'def', 'baseline/screen:2')
 751   y = y + Editor_state.line_height
 752   App.screen.check(y, 'ghi', 'baseline/screen:3')
 753   -- hitting the enter key splits the line
 754   edit.run_after_keychord(Editor_state, 'return')
 755   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
 756   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
 757   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
 758   y = Editor_state.top
 759   App.screen.check(y, 'a', 'screen:1')
 760   y = y + Editor_state.line_height
 761   App.screen.check(y, 'bc', 'screen:2')
 762   y = y + Editor_state.line_height
 763   App.screen.check(y, 'def', 'screen:3')
 764 end
 765
 766 function test_insert_newline_at_start_of_line()
 767   -- display a line
 768   App.screen.init{width=Editor_state.left+30, height=60}
 769   Editor_state = edit.initialize_test_state()
 770   Editor_state.lines = load_array{'abc'}
 771   Text.redraw_all(Editor_state)
 772   Editor_state.cursor1 = {line=1, pos=1}
 773   Editor_state.screen_top1 = {line=1, pos=1}
 774   Editor_state.screen_bottom1 = {}
 775   -- hitting the enter key splits the line
 776   edit.run_after_keychord(Editor_state, 'return')
 777   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
 778   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
 779   check_eq(Editor_state.lines[1].data, '', 'data:1')
 780   check_eq(Editor_state.lines[2].data, 'abc', 'data:2')
 781 end
 782
 783 function test_insert_from_clipboard()
 784   -- display a few lines
 785   App.screen.init{width=Editor_state.left+30, height=60}
 786   Editor_state = edit.initialize_test_state()
 787   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
 788   Text.redraw_all(Editor_state)
 789   Editor_state.cursor1 = {line=1, pos=2}
 790   Editor_state.screen_top1 = {line=1, pos=1}
 791   Editor_state.screen_bottom1 = {}
 792   edit.draw(Editor_state)
 793   local y = Editor_state.top
 794   App.screen.check(y, 'abc', 'baseline/screen:1')
 795   y = y + Editor_state.line_height
 796   App.screen.check(y, 'def', 'baseline/screen:2')
 797   y = y + Editor_state.line_height
 798   App.screen.check(y, 'ghi', 'baseline/screen:3')
 799   -- paste some text including a newline, check that new line is created
 800   App.clipboard = 'xy\nz'
 801   edit.run_after_keychord(Editor_state, 'C-v')
 802   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
 803   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
 804   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 805   y = Editor_state.top
 806   App.screen.check(y, 'axy', 'screen:1')
 807   y = y + Editor_state.line_height
 808   App.screen.check(y, 'zbc', 'screen:2')
 809   y = y + Editor_state.line_height
 810   App.screen.check(y, 'def', 'screen:3')
 811 end
 812
 813 function test_select_text_using_mouse()
 814   App.screen.init{width=50, height=60}
 815   Editor_state = edit.initialize_test_state()
 816   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
 817   Text.redraw_all(Editor_state)
 818   Editor_state.cursor1 = {line=1, pos=1}
 819   Editor_state.screen_top1 = {line=1, pos=1}
 820   Editor_state.screen_bottom1 = {}
 821   Editor_state.selection1 = {}
 822   edit.draw(Editor_state)  -- populate line_cache.starty for each line Editor_state.line_cache
 823   -- press and hold on first location
 824   edit.run_after_mouse_press(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 825   -- drag and release somewhere else
 826   edit.run_after_mouse_release(Editor_state, Editor_state.left+20,Editor_state.top+Editor_state.line_height+5, 1)
 827   check_eq(Editor_state.selection1.line, 1, 'selection:line')
 828   check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
 829   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
 830   check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 831 end
 832
 833 function test_select_text_using_mouse_starting_above_text()
 834   App.screen.init{width=50, height=60}
 835   Editor_state = edit.initialize_test_state()
 836   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
 837   Text.redraw_all(Editor_state)
 838   Editor_state.cursor1 = {line=1, pos=1}
 839   Editor_state.screen_top1 = {line=1, pos=1}
 840   Editor_state.screen_bottom1 = {}
 841   Editor_state.selection1 = {}
 842   edit.draw(Editor_state)  -- populate line_cache.starty for each line Editor_state.line_cache
 843   -- press mouse above first line of text
 844   edit.run_after_mouse_press(Editor_state, Editor_state.left+8,5, 1)
 845   check(Editor_state.selection1.line ~= nil, 'selection:line-not-nil')
 846   check_eq(Editor_state.selection1.line, 1, 'selection:line')
 847   check_eq(Editor_state.selection1.pos, 1, 'selection:pos')
 848 end
 849
 850 function test_select_text_using_mouse_starting_above_text_wrapping_line()
 851   -- first screen line starts in the middle of a line
 852   App.screen.init{width=50, height=60}
 853   Editor_state = edit.initialize_test_state()
 854   Editor_state.lines = load_array{'abc', 'defgh', 'xyz'}
 855   Text.redraw_all(Editor_state)
 856   Editor_state.cursor1 = {line=2, pos=5}
 857   Editor_state.screen_top1 = {line=2, pos=3}
 858   Editor_state.screen_bottom1 = {}
 859   -- press mouse above first line of text
 860   edit.run_after_mouse_press(Editor_state, Editor_state.left+8,5, 1)
 861   -- selection is at screen top
 862   check(Editor_state.selection1.line ~= nil, 'selection:line-not-nil')
 863   check_eq(Editor_state.selection1.line, 2, 'selection:line')
 864   check_eq(Editor_state.selection1.pos, 3, 'selection:pos')
 865 end
 866
 867 function test_select_text_using_mouse_starting_below_text()
 868   -- I'd like to test what happens when a mouse click is below some page of
 869   -- text, potentially even in the middle of a line.
 870   -- However, it's brittle to set up a text line boundary just right.
 871   -- So I'm going to just check things below the bottom of the final line of
 872   -- text when it's in the middle of the screen.
 873   -- final screen line ends in the middle of screen
 874   App.screen.init{width=50, height=60}
 875   Editor_state = edit.initialize_test_state()
 876   Editor_state.lines = load_array{'abcde'}
 877   Text.redraw_all(Editor_state)
 878   Editor_state.cursor1 = {line=1, pos=1}
 879   Editor_state.screen_top1 = {line=1, pos=1}
 880   Editor_state.screen_bottom1 = {}
 881   edit.draw(Editor_state)
 882   local y = Editor_state.top
 883   App.screen.check(y, 'ab', 'baseline:screen:1')
 884   y = y + Editor_state.line_height
 885   App.screen.check(y, 'cde', 'baseline:screen:2')
 886   -- press mouse above first line of text
 887   edit.run_after_mouse_press(Editor_state, 5,App.screen.height-5, 1)
 888   -- selection is past bottom-most text in screen
 889   check(Editor_state.selection1.line ~= nil, 'selection:line-not-nil')
 890   check_eq(Editor_state.selection1.line, 1, 'selection:line')
 891   check_eq(Editor_state.selection1.pos, 6, 'selection:pos')
 892 end
 893
 894 function test_select_text_using_mouse_and_shift()
 895   App.screen.init{width=50, height=60}
 896   Editor_state = edit.initialize_test_state()
 897   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
 898   Text.redraw_all(Editor_state)
 899   Editor_state.cursor1 = {line=1, pos=1}
 900   Editor_state.screen_top1 = {line=1, pos=1}
 901   Editor_state.screen_bottom1 = {}
 902   Editor_state.selection1 = {}
 903   edit.draw(Editor_state)  -- populate line_cache.starty for each line Editor_state.line_cache
 904   -- click on first location
 905   edit.run_after_mouse_press(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 906   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 907   -- hold down shift and click somewhere else
 908   App.fake_key_press('lshift')
 909   edit.run_after_mouse_press(Editor_state, Editor_state.left+20,Editor_state.top+5, 1)
 910   edit.run_after_mouse_release(Editor_state, Editor_state.left+20,Editor_state.top+Editor_state.line_height+5, 1)
 911   App.fake_key_release('lshift')
 912   check_eq(Editor_state.selection1.line, 1, 'selection:line')
 913   check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
 914   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
 915   check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 916 end
 917
 918 function test_select_text_repeatedly_using_mouse_and_shift()
 919   App.screen.init{width=50, height=60}
 920   Editor_state = edit.initialize_test_state()
 921   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
 922   Text.redraw_all(Editor_state)
 923   Text.redraw_all(Editor_state)
 924   Editor_state.cursor1 = {line=1, pos=1}
 925   Editor_state.screen_top1 = {line=1, pos=1}
 926   Editor_state.screen_bottom1 = {}
 927   Editor_state.selection1 = {}
 928   edit.draw(Editor_state)  -- populate line_cache.starty for each line Editor_state.line_cache
 929   -- click on first location
 930   edit.run_after_mouse_press(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 931   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
 932   -- hold down shift and click on a second location
 933   App.fake_key_press('lshift')
 934   edit.run_after_mouse_press(Editor_state, Editor_state.left+20,Editor_state.top+5, 1)
 935   edit.run_after_mouse_release(Editor_state, Editor_state.left+20,Editor_state.top+Editor_state.line_height+5, 1)
 936   -- hold down shift and click at a third location
 937   App.fake_key_press('lshift')
 938   edit.run_after_mouse_press(Editor_state, Editor_state.left+20,Editor_state.top+5, 1)
 939   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+Editor_state.line_height+5, 1)
 940   App.fake_key_release('lshift')
 941   -- selection is between first and third location. forget the second location, not the first.
 942   check_eq(Editor_state.selection1.line, 1, 'selection:line')
 943   check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
 944   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
 945   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 946 end
 947
 948 function test_select_all_text()
 949   -- display a single line of text
 950   App.screen.init{width=75, height=80}
 951   Editor_state = edit.initialize_test_state()
 952   Editor_state.lines = load_array{'abc def'}
 953   Text.redraw_all(Editor_state)
 954   Editor_state.cursor1 = {line=1, pos=1}
 955   Editor_state.screen_top1 = {line=1, pos=1}
 956   Editor_state.screen_bottom1 = {}
 957   edit.draw(Editor_state)
 958   -- select all
 959   App.fake_key_press('lctrl')
 960   edit.run_after_keychord(Editor_state, 'C-a')
 961   App.fake_key_release('lctrl')
 962   edit.key_release(Editor_state, 'lctrl')
 963   -- selection
 964   check_eq(Editor_state.selection1.line, 1, 'selection:line')
 965   check_eq(Editor_state.selection1.pos, 1, 'selection:pos')
 966   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
 967   check_eq(Editor_state.cursor1.pos, 8, 'cursor:pos')
 968 end
 969
 970 function test_cut_without_selection()
 971   -- display a few lines
 972   App.screen.init{width=Editor_state.left+30, height=60}
 973   Editor_state = edit.initialize_test_state()
 974   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
 975   Text.redraw_all(Editor_state)
 976   Editor_state.cursor1 = {line=1, pos=2}
 977   Editor_state.screen_top1 = {line=1, pos=1}
 978   Editor_state.screen_bottom1 = {}
 979   Editor_state.selection1 = {}
 980   edit.draw(Editor_state)
 981   -- try to cut without selecting text
 982   edit.run_after_keychord(Editor_state, 'C-x')
 983   -- no crash
 984   check_nil(Editor_state.selection1.line, 'check')
 985 end
 986
 987 function test_pagedown()
 988   App.screen.init{width=120, height=45}
 989   Editor_state = edit.initialize_test_state()
 990   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
 991   Text.redraw_all(Editor_state)
 992   Editor_state.cursor1 = {line=1, pos=1}
 993   Editor_state.screen_top1 = {line=1, pos=1}
 994   Editor_state.screen_bottom1 = {}
 995   -- initially the first two lines are displayed
 996   edit.draw(Editor_state)
 997   local y = Editor_state.top
 998   App.screen.check(y, 'abc', 'baseline/screen:1')
 999   y = y + Editor_state.line_height
1000   App.screen.check(y, 'def', 'baseline/screen:2')
1001   -- after pagedown the bottom line becomes the top
1002   edit.run_after_keychord(Editor_state, 'pagedown')
1003   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1004   check_eq(Editor_state.cursor1.line, 2, 'cursor')
1005   y = Editor_state.top
1006   App.screen.check(y, 'def', 'screen:1')
1007   y = y + Editor_state.line_height
1008   App.screen.check(y, 'ghi', 'screen:2')
1009 end
1010
1011 function test_pagedown_skips_drawings()
1012   -- some lines of text with a drawing intermixed
1013   local drawing_width = 50
1014   App.screen.init{width=Editor_state.left+drawing_width, height=80}
1015   Editor_state = edit.initialize_test_state()
1016   Editor_state.lines = load_array{'abc',               -- height 15
1017                                   '```lines', '```',   -- height 25
1018                                   'def',               -- height 15
1019                                   'ghi'}               -- height 15
1020   Text.redraw_all(Editor_state)
1021   check_eq(Editor_state.lines[2].mode, 'drawing', 'baseline/lines')
1022   Editor_state.cursor1 = {line=1, pos=1}
1023   Editor_state.screen_top1 = {line=1, pos=1}
1024   Editor_state.screen_bottom1 = {}
1025   local drawing_height = Drawing_padding_height + drawing_width/2  -- default
1026   -- initially the screen displays the first line and the drawing
1027   -- 15px margin + 15px line1 + 10px margin + 25px drawing + 10px margin = 75px < screen height 80px
1028   edit.draw(Editor_state)
1029   local y = Editor_state.top
1030   App.screen.check(y, 'abc', 'baseline/screen:1')
1031   -- after pagedown the screen draws the drawing up top
1032   -- 15px margin + 10px margin + 25px drawing + 10px margin + 15px line3 = 75px < screen height 80px
1033   edit.run_after_keychord(Editor_state, 'pagedown')
1034   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1035   check_eq(Editor_state.cursor1.line, 3, 'cursor')
1036   y = Editor_state.top + drawing_height
1037   App.screen.check(y, 'def', 'screen:1')
1038 end
1039
1040 function test_pagedown_often_shows_start_of_wrapping_line()
1041   -- draw a few lines ending in part of a wrapping line
1042   App.screen.init{width=50, height=60}
1043   Editor_state = edit.initialize_test_state()
1044   Editor_state.lines = load_array{'abc', 'def ghi jkl', 'mno'}
1045   Text.redraw_all(Editor_state)
1046   Editor_state.cursor1 = {line=1, pos=1}
1047   Editor_state.screen_top1 = {line=1, pos=1}
1048   Editor_state.screen_bottom1 = {}
1049   edit.draw(Editor_state)
1050   local y = Editor_state.top
1051   App.screen.check(y, 'abc', 'baseline/screen:1')
1052   y = y + Editor_state.line_height
1053   App.screen.check(y, 'def ', 'baseline/screen:2')
1054   y = y + Editor_state.line_height
1055   App.screen.check(y, 'ghi ', 'baseline/screen:3')
1056   -- after pagedown we start drawing from the bottom _line_ (multiple screen lines)
1057   edit.run_after_keychord(Editor_state, 'pagedown')
1058   check_eq(Editor_state.screen_top1.line, 2, 'screen_top:line')
1059   check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
1060   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
1061   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1062   y = Editor_state.top
1063   App.screen.check(y, 'def ', 'screen:1')
1064   y = y + Editor_state.line_height
1065   App.screen.check(y, 'ghi ', 'screen:2')
1066   y = y + Editor_state.line_height
1067   App.screen.check(y, 'jkl', 'screen:3')
1068 end
1069
1070 function test_pagedown_can_start_from_middle_of_long_wrapping_line()
1071   -- draw a few lines starting from a very long wrapping line
1072   App.screen.init{width=Editor_state.left+30, height=60}
1073   Editor_state = edit.initialize_test_state()
1074   Editor_state.lines = load_array{'abc def ghi jkl mno pqr stu vwx yza bcd efg hij', 'XYZ'}
1075   Text.redraw_all(Editor_state)
1076   Editor_state.cursor1 = {line=1, pos=2}
1077   Editor_state.screen_top1 = {line=1, pos=1}
1078   Editor_state.screen_bottom1 = {}
1079   edit.draw(Editor_state)
1080   local y = Editor_state.top
1081   App.screen.check(y, 'abc ', 'baseline/screen:1')
1082   y = y + Editor_state.line_height
1083   App.screen.check(y, 'def ', 'baseline/screen:2')
1084   y = y + Editor_state.line_height
1085   App.screen.check(y, 'ghi ', 'baseline/screen:3')
1086   -- after pagedown we scroll down the very long wrapping line
1087   edit.run_after_keychord(Editor_state, 'pagedown')
1088   check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
1089   check_eq(Editor_state.screen_top1.pos, 9, 'screen_top:pos')
1090   y = Editor_state.top
1091   App.screen.check(y, 'ghi ', 'screen:1')
1092   y = y + Editor_state.line_height
1093   App.screen.check(y, 'jkl ', 'screen:2')
1094   y = y + Editor_state.line_height
1095   App.screen.check(y, 'mn', 'screen:3')
1096 end
1097
1098 function test_pagedown_never_moves_up()
1099   -- draw the final screen line of a wrapping line
1100   App.screen.init{width=Editor_state.left+30, height=60}
1101   Editor_state = edit.initialize_test_state()
1102   Editor_state.lines = load_array{'abc def ghi'}
1103   Text.redraw_all(Editor_state)
1104   Editor_state.cursor1 = {line=1, pos=9}
1105   Editor_state.screen_top1 = {line=1, pos=9}
1106   Editor_state.screen_bottom1 = {}
1107   edit.draw(Editor_state)
1108   -- pagedown makes no change
1109   edit.run_after_keychord(Editor_state, 'pagedown')
1110   check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
1111   check_eq(Editor_state.screen_top1.pos, 9, 'screen_top:pos')
1112 end
1113
1114 function test_down_arrow_moves_cursor()
1115   App.screen.init{width=120, height=60}
1116   Editor_state = edit.initialize_test_state()
1117   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1118   Text.redraw_all(Editor_state)
1119   Editor_state.cursor1 = {line=1, pos=1}
1120   Editor_state.screen_top1 = {line=1, pos=1}
1121   Editor_state.screen_bottom1 = {}
1122   -- initially the first three lines are displayed
1123   edit.draw(Editor_state)
1124   local y = Editor_state.top
1125   App.screen.check(y, 'abc', 'baseline/screen:1')
1126   y = y + Editor_state.line_height
1127   App.screen.check(y, 'def', 'baseline/screen:2')
1128   y = y + Editor_state.line_height
1129   App.screen.check(y, 'ghi', 'baseline/screen:3')
1130   -- after hitting the down arrow, the cursor moves down by 1 line
1131   edit.run_after_keychord(Editor_state, 'down')
1132   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1133   check_eq(Editor_state.cursor1.line, 2, 'cursor')
1134   -- the screen is unchanged
1135   y = Editor_state.top
1136   App.screen.check(y, 'abc', 'screen:1')
1137   y = y + Editor_state.line_height
1138   App.screen.check(y, 'def', 'screen:2')
1139   y = y + Editor_state.line_height
1140   App.screen.check(y, 'ghi', 'screen:3')
1141 end
1142
1143 function test_down_arrow_skips_drawing()
1144   -- some lines of text with a drawing intermixed
1145   local drawing_width = 50
1146   App.screen.init{width=Editor_state.left+drawing_width, height=100}
1147   Editor_state = edit.initialize_test_state()
1148   Editor_state.lines = load_array{'abc',               -- height 15
1149                                   '```lines', '```',   -- height 25
1150                                   'ghi'}
1151   Text.redraw_all(Editor_state)
1152   Editor_state.cursor1 = {line=1, pos=1}
1153   Editor_state.screen_top1 = {line=1, pos=1}
1154   Editor_state.screen_bottom1 = {}
1155   edit.draw(Editor_state)
1156   local y = Editor_state.top
1157   App.screen.check(y, 'abc', 'baseline/screen:1')
1158   y = y + Editor_state.line_height
1159   local drawing_height = Drawing_padding_height + drawing_width/2  -- default
1160   y = y + drawing_height
1161   App.screen.check(y, 'ghi', 'baseline/screen:3')
1162   check(Editor_state.cursor_x, 'baseline/cursor_x')
1163   -- after hitting the down arrow the cursor moves down by 2 lines, skipping the drawing
1164   edit.run_after_keychord(Editor_state, 'down')
1165   check_eq(Editor_state.cursor1.line, 3, 'cursor')
1166 end
1167
1168 function test_down_arrow_scrolls_down_by_one_line()
1169   -- display the first three lines with the cursor on the bottom line
1170   App.screen.init{width=120, height=60}
1171   Editor_state = edit.initialize_test_state()
1172   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1173   Text.redraw_all(Editor_state)
1174   Editor_state.cursor1 = {line=3, pos=1}
1175   Editor_state.screen_top1 = {line=1, pos=1}
1176   Editor_state.screen_bottom1 = {}
1177   edit.draw(Editor_state)
1178   local y = Editor_state.top
1179   App.screen.check(y, 'abc', 'baseline/screen:1')
1180   y = y + Editor_state.line_height
1181   App.screen.check(y, 'def', 'baseline/screen:2')
1182   y = y + Editor_state.line_height
1183   App.screen.check(y, 'ghi', 'baseline/screen:3')
1184   -- after hitting the down arrow the screen scrolls down by one line
1185   edit.run_after_keychord(Editor_state, 'down')
1186   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1187   check_eq(Editor_state.cursor1.line, 4, 'cursor')
1188   y = Editor_state.top
1189   App.screen.check(y, 'def', 'screen:1')
1190   y = y + Editor_state.line_height
1191   App.screen.check(y, 'ghi', 'screen:2')
1192   y = y + Editor_state.line_height
1193   App.screen.check(y, 'jkl', 'screen:3')
1194 end
1195
1196 function test_down_arrow_scrolls_down_by_one_screen_line()
1197   -- display the first three lines with the cursor on the bottom line
1198   App.screen.init{width=Editor_state.left+30, height=60}
1199   Editor_state = edit.initialize_test_state()
1200   Editor_state.lines = load_array{'abc', 'def', 'ghi jkl', 'mno'}
1201   Text.redraw_all(Editor_state)
1202   Editor_state.cursor1 = {line=3, pos=1}
1203   Editor_state.screen_top1 = {line=1, pos=1}
1204   Editor_state.screen_bottom1 = {}
1205   edit.draw(Editor_state)
1206   local y = Editor_state.top
1207   App.screen.check(y, 'abc', 'baseline/screen:1')
1208   y = y + Editor_state.line_height
1209   App.screen.check(y, 'def', 'baseline/screen:2')
1210   y = y + Editor_state.line_height
1211   App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
1212   -- after hitting the down arrow the screen scrolls down by one line
1213   edit.run_after_keychord(Editor_state, 'down')
1214   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1215   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1216   check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
1217   y = Editor_state.top
1218   App.screen.check(y, 'def', 'screen:1')
1219   y = y + Editor_state.line_height
1220   App.screen.check(y, 'ghi ', 'screen:2')
1221   y = y + Editor_state.line_height
1222   App.screen.check(y, 'jkl', 'screen:3')
1223 end
1224
1225 function test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word()
1226   -- display the first three lines with the cursor on the bottom line
1227   App.screen.init{width=Editor_state.left+30, height=60}
1228   Editor_state = edit.initialize_test_state()
1229   Editor_state.lines = load_array{'abc', 'def', 'ghijkl', 'mno'}
1230   Text.redraw_all(Editor_state)
1231   Editor_state.cursor1 = {line=3, pos=1}
1232   Editor_state.screen_top1 = {line=1, pos=1}
1233   Editor_state.screen_bottom1 = {}
1234   edit.draw(Editor_state)
1235   local y = Editor_state.top
1236   App.screen.check(y, 'abc', 'baseline/screen:1')
1237   y = y + Editor_state.line_height
1238   App.screen.check(y, 'def', 'baseline/screen:2')
1239   y = y + Editor_state.line_height
1240   App.screen.check(y, 'ghij', 'baseline/screen:3')
1241   -- after hitting the down arrow the screen scrolls down by one line
1242   edit.run_after_keychord(Editor_state, 'down')
1243   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1244   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1245   check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
1246   y = Editor_state.top
1247   App.screen.check(y, 'def', 'screen:1')
1248   y = y + Editor_state.line_height
1249   App.screen.check(y, 'ghij', 'screen:2')
1250   y = y + Editor_state.line_height
1251   App.screen.check(y, 'kl', 'screen:3')
1252 end
1253
1254 function test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up()
1255   App.screen.init{width=Editor_state.left+30, height=60}
1256   Editor_state = edit.initialize_test_state()
1257   Editor_state.lines = load_array{'abc', 'def', 'ghijkl', 'mno'}
1258   Text.redraw_all(Editor_state)
1259   Editor_state.cursor1 = {line=3, pos=1}
1260   Editor_state.screen_top1 = {line=1, pos=1}
1261   Editor_state.screen_bottom1 = {}
1262   edit.draw(Editor_state)
1263   local y = Editor_state.top
1264   App.screen.check(y, 'abc', 'baseline/screen:1')
1265   y = y + Editor_state.line_height
1266   App.screen.check(y, 'def', 'baseline/screen:2')
1267   y = y + Editor_state.line_height
1268   App.screen.check(y, 'ghij', 'baseline/screen:3')
1269   -- after hitting pagedown the screen scrolls down to start of a long line
1270   edit.run_after_keychord(Editor_state, 'pagedown')
1271   check_eq(Editor_state.screen_top1.line, 3, 'baseline2/screen_top')
1272   check_eq(Editor_state.cursor1.line, 3, 'baseline2/cursor:line')
1273   check_eq(Editor_state.cursor1.pos, 1, 'baseline2/cursor:pos')
1274   -- after hitting down arrow the screen doesn't scroll down further, and certainly doesn't scroll up
1275   edit.run_after_keychord(Editor_state, 'down')
1276   check_eq(Editor_state.screen_top1.line, 3, 'screen_top')
1277   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1278   check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
1279   y = Editor_state.top
1280   App.screen.check(y, 'ghij', 'screen:1')
1281   y = y + Editor_state.line_height
1282   App.screen.check(y, 'kl', 'screen:2')
1283   y = y + Editor_state.line_height
1284   App.screen.check(y, 'mno', 'screen:3')
1285 end
1286
1287 function test_up_arrow_moves_cursor()
1288   -- display the first 3 lines with the cursor on the bottom line
1289   App.screen.init{width=120, height=60}
1290   Editor_state = edit.initialize_test_state()
1291   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1292   Text.redraw_all(Editor_state)
1293   Editor_state.cursor1 = {line=3, pos=1}
1294   Editor_state.screen_top1 = {line=1, pos=1}
1295   Editor_state.screen_bottom1 = {}
1296   edit.draw(Editor_state)
1297   local y = Editor_state.top
1298   App.screen.check(y, 'abc', 'baseline/screen:1')
1299   y = y + Editor_state.line_height
1300   App.screen.check(y, 'def', 'baseline/screen:2')
1301   y = y + Editor_state.line_height
1302   App.screen.check(y, 'ghi', 'baseline/screen:3')
1303   -- after hitting the up arrow the cursor moves up by 1 line
1304   edit.run_after_keychord(Editor_state, 'up')
1305   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1306   check_eq(Editor_state.cursor1.line, 2, 'cursor')
1307   -- the screen is unchanged
1308   y = Editor_state.top
1309   App.screen.check(y, 'abc', 'screen:1')
1310   y = y + Editor_state.line_height
1311   App.screen.check(y, 'def', 'screen:2')
1312   y = y + Editor_state.line_height
1313   App.screen.check(y, 'ghi', 'screen:3')
1314 end
1315
1316 function test_up_arrow_skips_drawing()
1317   -- some lines of text with a drawing intermixed
1318   local drawing_width = 50
1319   App.screen.init{width=Editor_state.left+drawing_width, height=100}
1320   Editor_state = edit.initialize_test_state()
1321   Editor_state.lines = load_array{'abc',               -- height 15
1322                                   '```lines', '```',   -- height 25
1323                                   'ghi'}
1324   Text.redraw_all(Editor_state)
1325   Editor_state.cursor1 = {line=3, pos=1}
1326   Editor_state.screen_top1 = {line=1, pos=1}
1327   Editor_state.screen_bottom1 = {}
1328   edit.draw(Editor_state)
1329   local y = Editor_state.top
1330   App.screen.check(y, 'abc', 'baseline/screen:1')
1331   y = y + Editor_state.line_height
1332   local drawing_height = Drawing_padding_height + drawing_width/2  -- default
1333   y = y + drawing_height
1334   App.screen.check(y, 'ghi', 'baseline/screen:3')
1335   check(Editor_state.cursor_x, 'baseline/cursor_x')
1336   -- after hitting the up arrow the cursor moves up by 2 lines, skipping the drawing
1337   edit.run_after_keychord(Editor_state, 'up')
1338   check_eq(Editor_state.cursor1.line, 1, 'cursor')
1339 end
1340
1341 function test_up_arrow_scrolls_up_by_one_line()
1342   -- display the lines 2/3/4 with the cursor on line 2
1343   App.screen.init{width=120, height=60}
1344   Editor_state = edit.initialize_test_state()
1345   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1346   Text.redraw_all(Editor_state)
1347   Editor_state.cursor1 = {line=2, pos=1}
1348   Editor_state.screen_top1 = {line=2, pos=1}
1349   Editor_state.screen_bottom1 = {}
1350   edit.draw(Editor_state)
1351   local y = Editor_state.top
1352   App.screen.check(y, 'def', 'baseline/screen:1')
1353   y = y + Editor_state.line_height
1354   App.screen.check(y, 'ghi', 'baseline/screen:2')
1355   y = y + Editor_state.line_height
1356   App.screen.check(y, 'jkl', 'baseline/screen:3')
1357   -- after hitting the up arrow the screen scrolls up by one line
1358   edit.run_after_keychord(Editor_state, 'up')
1359   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1360   check_eq(Editor_state.cursor1.line, 1, 'cursor')
1361   y = Editor_state.top
1362   App.screen.check(y, 'abc', 'screen:1')
1363   y = y + Editor_state.line_height
1364   App.screen.check(y, 'def', 'screen:2')
1365   y = y + Editor_state.line_height
1366   App.screen.check(y, 'ghi', 'screen:3')
1367 end
1368
1369 function test_up_arrow_scrolls_up_by_one_line_skipping_drawing()
1370   -- display lines 3/4/5 with a drawing just off screen at line 2
1371   App.screen.init{width=120, height=60}
1372   Editor_state = edit.initialize_test_state()
1373   Editor_state.lines = load_array{'abc', '```lines', '```', 'def', 'ghi', 'jkl'}
1374   Text.redraw_all(Editor_state)
1375   Editor_state.cursor1 = {line=3, pos=1}
1376   Editor_state.screen_top1 = {line=3, pos=1}
1377   Editor_state.screen_bottom1 = {}
1378   edit.draw(Editor_state)
1379   local y = Editor_state.top
1380   App.screen.check(y, 'def', 'baseline/screen:1')
1381   y = y + Editor_state.line_height
1382   App.screen.check(y, 'ghi', 'baseline/screen:2')
1383   y = y + Editor_state.line_height
1384   App.screen.check(y, 'jkl', 'baseline/screen:3')
1385   -- after hitting the up arrow the screen scrolls up to previous text line
1386   edit.run_after_keychord(Editor_state, 'up')
1387   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1388   check_eq(Editor_state.cursor1.line, 1, 'cursor')
1389 end
1390
1391 function test_up_arrow_scrolls_up_by_one_screen_line()
1392   -- display lines starting from second screen line of a line
1393   App.screen.init{width=Editor_state.left+30, height=60}
1394   Editor_state = edit.initialize_test_state()
1395   Editor_state.lines = load_array{'abc', 'def', 'ghi jkl', 'mno'}
1396   Text.redraw_all(Editor_state)
1397   Editor_state.cursor1 = {line=3, pos=6}
1398   Editor_state.screen_top1 = {line=3, pos=5}
1399   Editor_state.screen_bottom1 = {}
1400   edit.draw(Editor_state)
1401   local y = Editor_state.top
1402   App.screen.check(y, 'jkl', 'baseline/screen:1')
1403   y = y + Editor_state.line_height
1404   App.screen.check(y, 'mno', 'baseline/screen:2')
1405   -- after hitting the up arrow the screen scrolls up to first screen line
1406   edit.run_after_keychord(Editor_state, 'up')
1407   y = Editor_state.top
1408   App.screen.check(y, 'ghi ', 'screen:1')
1409   y = y + Editor_state.line_height
1410   App.screen.check(y, 'jkl', 'screen:2')
1411   y = y + Editor_state.line_height
1412   App.screen.check(y, 'mno', 'screen:3')
1413   check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
1414   check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
1415   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1416   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1417 end
1418
1419 function test_up_arrow_scrolls_up_to_final_screen_line()
1420   -- display lines starting just after a long line
1421   App.screen.init{width=Editor_state.left+30, height=60}
1422   Editor_state = edit.initialize_test_state()
1423   Editor_state.lines = load_array{'abc def', 'ghi', 'jkl', 'mno'}
1424   Text.redraw_all(Editor_state)
1425   Editor_state.cursor1 = {line=2, pos=1}
1426   Editor_state.screen_top1 = {line=2, pos=1}
1427   Editor_state.screen_bottom1 = {}
1428   edit.draw(Editor_state)
1429   local y = Editor_state.top
1430   App.screen.check(y, 'ghi', 'baseline/screen:1')
1431   y = y + Editor_state.line_height
1432   App.screen.check(y, 'jkl', 'baseline/screen:2')
1433   y = y + Editor_state.line_height
1434   App.screen.check(y, 'mno', 'baseline/screen:3')
1435   -- after hitting the up arrow the screen scrolls up to final screen line of previous line
1436   edit.run_after_keychord(Editor_state, 'up')
1437   y = Editor_state.top
1438   App.screen.check(y, 'def', 'screen:1')
1439   y = y + Editor_state.line_height
1440   App.screen.check(y, 'ghi', 'screen:2')
1441   y = y + Editor_state.line_height
1442   App.screen.check(y, 'jkl', 'screen:3')
1443   check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
1444   check_eq(Editor_state.screen_top1.pos, 5, 'screen_top:pos')
1445   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1446   check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
1447 end
1448
1449 function test_up_arrow_scrolls_up_to_empty_line()
1450   -- display a screenful of text with an empty line just above it outside the screen
1451   App.screen.init{width=120, height=60}
1452   Editor_state = edit.initialize_test_state()
1453   Editor_state.lines = load_array{'', 'abc', 'def', 'ghi', 'jkl'}
1454   Text.redraw_all(Editor_state)
1455   Editor_state.cursor1 = {line=2, pos=1}
1456   Editor_state.screen_top1 = {line=2, pos=1}
1457   Editor_state.screen_bottom1 = {}
1458   edit.draw(Editor_state)
1459   local y = Editor_state.top
1460   App.screen.check(y, 'abc', 'baseline/screen:1')
1461   y = y + Editor_state.line_height
1462   App.screen.check(y, 'def', 'baseline/screen:2')
1463   y = y + Editor_state.line_height
1464   App.screen.check(y, 'ghi', 'baseline/screen:3')
1465   -- after hitting the up arrow the screen scrolls up by one line
1466   edit.run_after_keychord(Editor_state, 'up')
1467   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1468   check_eq(Editor_state.cursor1.line, 1, 'cursor')
1469   y = Editor_state.top
1470   -- empty first line
1471   y = y + Editor_state.line_height
1472   App.screen.check(y, 'abc', 'screen:2')
1473   y = y + Editor_state.line_height
1474   App.screen.check(y, 'def', 'screen:3')
1475 end
1476
1477 function test_pageup()
1478   App.screen.init{width=120, height=45}
1479   Editor_state = edit.initialize_test_state()
1480   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
1481   Text.redraw_all(Editor_state)
1482   Editor_state.cursor1 = {line=2, pos=1}
1483   Editor_state.screen_top1 = {line=2, pos=1}
1484   Editor_state.screen_bottom1 = {}
1485   -- initially the last two lines are displayed
1486   edit.draw(Editor_state)
1487   local y = Editor_state.top
1488   App.screen.check(y, 'def', 'baseline/screen:1')
1489   y = y + Editor_state.line_height
1490   App.screen.check(y, 'ghi', 'baseline/screen:2')
1491   -- after pageup the cursor goes to first line
1492   edit.run_after_keychord(Editor_state, 'pageup')
1493   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1494   check_eq(Editor_state.cursor1.line, 1, 'cursor')
1495   y = Editor_state.top
1496   App.screen.check(y, 'abc', 'screen:1')
1497   y = y + Editor_state.line_height
1498   App.screen.check(y, 'def', 'screen:2')
1499 end
1500
1501 function test_pageup_scrolls_up_by_screen_line()
1502   -- display the first three lines with the cursor on the bottom line
1503   App.screen.init{width=Editor_state.left+30, height=60}
1504   Editor_state = edit.initialize_test_state()
1505   Editor_state.lines = load_array{'abc def', 'ghi', 'jkl', 'mno'}
1506   Text.redraw_all(Editor_state)
1507   Editor_state.cursor1 = {line=2, pos=1}
1508   Editor_state.screen_top1 = {line=2, pos=1}
1509   Editor_state.screen_bottom1 = {}
1510   edit.draw(Editor_state)
1511   local y = Editor_state.top
1512   App.screen.check(y, 'ghi', 'baseline/screen:1')
1513   y = y + Editor_state.line_height
1514   App.screen.check(y, 'jkl', 'baseline/screen:2')
1515   y = y + Editor_state.line_height
1516   App.screen.check(y, 'mno', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
1517   -- after hitting the page-up key the screen scrolls up to top
1518   edit.run_after_keychord(Editor_state, 'pageup')
1519   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1520   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1521   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1522   y = Editor_state.top
1523   App.screen.check(y, 'abc ', 'screen:1')
1524   y = y + Editor_state.line_height
1525   App.screen.check(y, 'def', 'screen:2')
1526   y = y + Editor_state.line_height
1527   App.screen.check(y, 'ghi', 'screen:3')
1528 end
1529
1530 function test_pageup_scrolls_up_from_middle_screen_line()
1531   -- display a few lines starting from the middle of a line (Editor_state.cursor1.pos > 1)
1532   App.screen.init{width=Editor_state.left+30, height=60}
1533   Editor_state = edit.initialize_test_state()
1534   Editor_state.lines = load_array{'abc def', 'ghi jkl', 'mno'}
1535   Text.redraw_all(Editor_state)
1536   Editor_state.cursor1 = {line=2, pos=5}
1537   Editor_state.screen_top1 = {line=2, pos=5}
1538   Editor_state.screen_bottom1 = {}
1539   edit.draw(Editor_state)
1540   local y = Editor_state.top
1541   App.screen.check(y, 'jkl', 'baseline/screen:2')
1542   y = y + Editor_state.line_height
1543   App.screen.check(y, 'mno', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
1544   -- after hitting the page-up key the screen scrolls up to top
1545   edit.run_after_keychord(Editor_state, 'pageup')
1546   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1547   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1548   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1549   y = Editor_state.top
1550   App.screen.check(y, 'abc ', 'screen:1')
1551   y = y + Editor_state.line_height
1552   App.screen.check(y, 'def', 'screen:2')
1553   y = y + Editor_state.line_height
1554   App.screen.check(y, 'ghi ', 'screen:3')
1555 end
1556
1557 function test_enter_on_bottom_line_scrolls_down()
1558   -- display a few lines with cursor on bottom line
1559   App.screen.init{width=Editor_state.left+30, height=60}
1560   Editor_state = edit.initialize_test_state()
1561   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1562   Text.redraw_all(Editor_state)
1563   Editor_state.cursor1 = {line=3, pos=2}
1564   Editor_state.screen_top1 = {line=1, pos=1}
1565   Editor_state.screen_bottom1 = {}
1566   edit.draw(Editor_state)
1567   local y = Editor_state.top
1568   App.screen.check(y, 'abc', 'baseline/screen:1')
1569   y = y + Editor_state.line_height
1570   App.screen.check(y, 'def', 'baseline/screen:2')
1571   y = y + Editor_state.line_height
1572   App.screen.check(y, 'ghi', 'baseline/screen:3')
1573   -- after hitting the enter key the screen scrolls down
1574   edit.run_after_keychord(Editor_state, 'return')
1575   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1576   check_eq(Editor_state.cursor1.line, 4, 'cursor:line')
1577   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1578   y = Editor_state.top
1579   App.screen.check(y, 'def', 'screen:1')
1580   y = y + Editor_state.line_height
1581   App.screen.check(y, 'g', 'screen:2')
1582   y = y + Editor_state.line_height
1583   App.screen.check(y, 'hi', 'screen:3')
1584 end
1585
1586 function test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom()
1587   -- display just the bottom line on screen
1588   App.screen.init{width=Editor_state.left+30, height=60}
1589   Editor_state = edit.initialize_test_state()
1590   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1591   Text.redraw_all(Editor_state)
1592   Editor_state.cursor1 = {line=4, pos=2}
1593   Editor_state.screen_top1 = {line=4, pos=1}
1594   Editor_state.screen_bottom1 = {}
1595   edit.draw(Editor_state)
1596   local y = Editor_state.top
1597   App.screen.check(y, 'jkl', 'baseline/screen:1')
1598   -- after hitting the enter key the screen does not scroll down
1599   edit.run_after_keychord(Editor_state, 'return')
1600   check_eq(Editor_state.screen_top1.line, 4, 'screen_top')
1601   check_eq(Editor_state.cursor1.line, 5, 'cursor:line')
1602   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1603   y = Editor_state.top
1604   App.screen.check(y, 'j', 'screen:1')
1605   y = y + Editor_state.line_height
1606   App.screen.check(y, 'kl', 'screen:2')
1607 end
1608
1609 function test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom()
1610   -- display just an empty bottom line on screen
1611   App.screen.init{width=Editor_state.left+30, height=60}
1612   Editor_state = edit.initialize_test_state()
1613   Editor_state.lines = load_array{'abc', ''}
1614   Text.redraw_all(Editor_state)
1615   Editor_state.cursor1 = {line=2, pos=1}
1616   Editor_state.screen_top1 = {line=2, pos=1}
1617   Editor_state.screen_bottom1 = {}
1618   edit.draw(Editor_state)
1619   -- after hitting the inserting_text key the screen does not scroll down
1620   edit.run_after_text_input(Editor_state, 'a')
1621   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1622   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
1623   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
1624   local y = Editor_state.top
1625   App.screen.check(y, 'a', 'screen:1')
1626 end
1627
1628 function test_typing_on_bottom_line_scrolls_down()
1629   -- display a few lines with cursor on bottom line
1630   App.screen.init{width=Editor_state.left+30, height=60}
1631   Editor_state = edit.initialize_test_state()
1632   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1633   Text.redraw_all(Editor_state)
1634   Editor_state.cursor1 = {line=3, pos=4}
1635   Editor_state.screen_top1 = {line=1, pos=1}
1636   Editor_state.screen_bottom1 = {}
1637   edit.draw(Editor_state)
1638   local y = Editor_state.top
1639   App.screen.check(y, 'abc', 'baseline/screen:1')
1640   y = y + Editor_state.line_height
1641   App.screen.check(y, 'def', 'baseline/screen:2')
1642   y = y + Editor_state.line_height
1643   App.screen.check(y, 'ghi', 'baseline/screen:3')
1644   -- after typing something the line wraps and the screen scrolls down
1645   edit.run_after_text_input(Editor_state, 'j')
1646   edit.run_after_text_input(Editor_state, 'k')
1647   edit.run_after_text_input(Editor_state, 'l')
1648   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1649   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1650   check_eq(Editor_state.cursor1.pos, 7, 'cursor:pos')
1651   y = Editor_state.top
1652   App.screen.check(y, 'def', 'screen:1')
1653   y = y + Editor_state.line_height
1654   App.screen.check(y, 'ghij', 'screen:2')
1655   y = y + Editor_state.line_height
1656   App.screen.check(y, 'kl', 'screen:3')
1657 end
1658
1659 function test_left_arrow_scrolls_up_in_wrapped_line()
1660   -- display lines starting from second screen line of a line
1661   App.screen.init{width=Editor_state.left+30, height=60}
1662   Editor_state = edit.initialize_test_state()
1663   Editor_state.lines = load_array{'abc', 'def', 'ghi jkl', 'mno'}
1664   Text.redraw_all(Editor_state)
1665   Editor_state.screen_top1 = {line=3, pos=5}
1666   Editor_state.screen_bottom1 = {}
1667   -- cursor is at top of screen
1668   Editor_state.cursor1 = {line=3, pos=5}
1669   edit.draw(Editor_state)
1670   local y = Editor_state.top
1671   App.screen.check(y, 'jkl', 'baseline/screen:1')
1672   y = y + Editor_state.line_height
1673   App.screen.check(y, 'mno', 'baseline/screen:2')
1674   -- after hitting the left arrow the screen scrolls up to first screen line
1675   edit.run_after_keychord(Editor_state, 'left')
1676   y = Editor_state.top
1677   App.screen.check(y, 'ghi ', 'screen:1')
1678   y = y + Editor_state.line_height
1679   App.screen.check(y, 'jkl', 'screen:2')
1680   y = y + Editor_state.line_height
1681   App.screen.check(y, 'mno', 'screen:3')
1682   check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
1683   check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
1684   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1685   check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
1686 end
1687
1688 function test_right_arrow_scrolls_down_in_wrapped_line()
1689   -- display the first three lines with the cursor on the bottom line
1690   App.screen.init{width=Editor_state.left+30, height=60}
1691   Editor_state = edit.initialize_test_state()
1692   Editor_state.lines = load_array{'abc', 'def', 'ghi jkl', 'mno'}
1693   Text.redraw_all(Editor_state)
1694   Editor_state.screen_top1 = {line=1, pos=1}
1695   Editor_state.screen_bottom1 = {}
1696   -- cursor is at bottom right of screen
1697   Editor_state.cursor1 = {line=3, pos=5}
1698   edit.draw(Editor_state)
1699   local y = Editor_state.top
1700   App.screen.check(y, 'abc', 'baseline/screen:1')
1701   y = y + Editor_state.line_height
1702   App.screen.check(y, 'def', 'baseline/screen:2')
1703   y = y + Editor_state.line_height
1704   App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
1705   -- after hitting the right arrow the screen scrolls down by one line
1706   edit.run_after_keychord(Editor_state, 'right')
1707   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1708   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1709   check_eq(Editor_state.cursor1.pos, 6, 'cursor:pos')
1710   y = Editor_state.top
1711   App.screen.check(y, 'def', 'screen:1')
1712   y = y + Editor_state.line_height
1713   App.screen.check(y, 'ghi ', 'screen:2')
1714   y = y + Editor_state.line_height
1715   App.screen.check(y, 'jkl', 'screen:3')
1716 end
1717
1718 function test_home_scrolls_up_in_wrapped_line()
1719   -- display lines starting from second screen line of a line
1720   App.screen.init{width=Editor_state.left+30, height=60}
1721   Editor_state = edit.initialize_test_state()
1722   Editor_state.lines = load_array{'abc', 'def', 'ghi jkl', 'mno'}
1723   Text.redraw_all(Editor_state)
1724   Editor_state.screen_top1 = {line=3, pos=5}
1725   Editor_state.screen_bottom1 = {}
1726   -- cursor is at top of screen
1727   Editor_state.cursor1 = {line=3, pos=5}
1728   edit.draw(Editor_state)
1729   local y = Editor_state.top
1730   App.screen.check(y, 'jkl', 'baseline/screen:1')
1731   y = y + Editor_state.line_height
1732   App.screen.check(y, 'mno', 'baseline/screen:2')
1733   -- after hitting home the screen scrolls up to first screen line
1734   edit.run_after_keychord(Editor_state, 'home')
1735   y = Editor_state.top
1736   App.screen.check(y, 'ghi ', 'screen:1')
1737   y = y + Editor_state.line_height
1738   App.screen.check(y, 'jkl', 'screen:2')
1739   y = y + Editor_state.line_height
1740   App.screen.check(y, 'mno', 'screen:3')
1741   check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
1742   check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
1743   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1744   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1745 end
1746
1747 function test_end_scrolls_down_in_wrapped_line()
1748   -- display the first three lines with the cursor on the bottom line
1749   App.screen.init{width=Editor_state.left+30, height=60}
1750   Editor_state = edit.initialize_test_state()
1751   Editor_state.lines = load_array{'abc', 'def', 'ghi jkl', 'mno'}
1752   Text.redraw_all(Editor_state)
1753   Editor_state.screen_top1 = {line=1, pos=1}
1754   Editor_state.screen_bottom1 = {}
1755   -- cursor is at bottom right of screen
1756   Editor_state.cursor1 = {line=3, pos=5}
1757   edit.draw(Editor_state)
1758   local y = Editor_state.top
1759   App.screen.check(y, 'abc', 'baseline/screen:1')
1760   y = y + Editor_state.line_height
1761   App.screen.check(y, 'def', 'baseline/screen:2')
1762   y = y + Editor_state.line_height
1763   App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
1764   -- after hitting end the screen scrolls down by one line
1765   edit.run_after_keychord(Editor_state, 'end')
1766   check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
1767   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1768   check_eq(Editor_state.cursor1.pos, 8, 'cursor:pos')
1769   y = Editor_state.top
1770   App.screen.check(y, 'def', 'screen:1')
1771   y = y + Editor_state.line_height
1772   App.screen.check(y, 'ghi ', 'screen:2')
1773   y = y + Editor_state.line_height
1774   App.screen.check(y, 'jkl', 'screen:3')
1775 end
1776
1777 function test_position_cursor_on_recently_edited_wrapping_line()
1778   -- draw a line wrapping over 2 screen lines
1779   App.screen.init{width=100, height=200}
1780   Editor_state = edit.initialize_test_state()
1781   Editor_state.lines = load_array{'abc def ghi jkl mno pqr ', 'xyz'}
1782   Text.redraw_all(Editor_state)
1783   Editor_state.cursor1 = {line=1, pos=25}
1784   Editor_state.screen_top1 = {line=1, pos=1}
1785   Editor_state.screen_bottom1 = {}
1786   edit.draw(Editor_state)
1787   local y = Editor_state.top
1788   App.screen.check(y, 'abc def ghi ', 'baseline1/screen:1')
1789   y = y + Editor_state.line_height
1790   App.screen.check(y, 'jkl mno pqr ', 'baseline1/screen:2')
1791   y = y + Editor_state.line_height
1792   App.screen.check(y, 'xyz', 'baseline1/screen:3')
1793   -- add to the line until it's wrapping over 3 screen lines
1794   edit.run_after_text_input(Editor_state, 's')
1795   edit.run_after_text_input(Editor_state, 't')
1796   edit.run_after_text_input(Editor_state, 'u')
1797   check_eq(Editor_state.cursor1.pos, 28, 'cursor:pos')
1798   y = Editor_state.top
1799   App.screen.check(y, 'abc def ghi ', 'baseline2/screen:1')
1800   y = y + Editor_state.line_height
1801   App.screen.check(y, 'jkl mno pqr ', 'baseline2/screen:2')
1802   y = y + Editor_state.line_height
1803   App.screen.check(y, 'stu', 'baseline2/screen:3')
1804   -- try to move the cursor earlier in the third screen line by clicking the mouse
1805   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+Editor_state.line_height*2+5, 1)
1806   -- cursor should move
1807   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1808   check_eq(Editor_state.cursor1.pos, 26, 'cursor:pos')
1809 end
1810
1811 function test_backspace_can_scroll_up()
1812   -- display the lines 2/3/4 with the cursor on line 2
1813   App.screen.init{width=120, height=60}
1814   Editor_state = edit.initialize_test_state()
1815   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
1816   Text.redraw_all(Editor_state)
1817   Editor_state.cursor1 = {line=2, pos=1}
1818   Editor_state.screen_top1 = {line=2, pos=1}
1819   Editor_state.screen_bottom1 = {}
1820   edit.draw(Editor_state)
1821   local y = Editor_state.top
1822   App.screen.check(y, 'def', 'baseline/screen:1')
1823   y = y + Editor_state.line_height
1824   App.screen.check(y, 'ghi', 'baseline/screen:2')
1825   y = y + Editor_state.line_height
1826   App.screen.check(y, 'jkl', 'baseline/screen:3')
1827   -- after hitting backspace the screen scrolls up by one line
1828   edit.run_after_keychord(Editor_state, 'backspace')
1829   check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
1830   check_eq(Editor_state.cursor1.line, 1, 'cursor')
1831   y = Editor_state.top
1832   App.screen.check(y, 'abcdef', 'screen:1')
1833   y = y + Editor_state.line_height
1834   App.screen.check(y, 'ghi', 'screen:2')
1835   y = y + Editor_state.line_height
1836   App.screen.check(y, 'jkl', 'screen:3')
1837 end
1838
1839 function test_backspace_can_scroll_up_screen_line()
1840   -- display lines starting from second screen line of a line
1841   App.screen.init{width=Editor_state.left+30, height=60}
1842   Editor_state = edit.initialize_test_state()
1843   Editor_state.lines = load_array{'abc', 'def', 'ghi jkl', 'mno'}
1844   Text.redraw_all(Editor_state)
1845   Editor_state.cursor1 = {line=3, pos=5}
1846   Editor_state.screen_top1 = {line=3, pos=5}
1847   Editor_state.screen_bottom1 = {}
1848   edit.draw(Editor_state)
1849   local y = Editor_state.top
1850   App.screen.check(y, 'jkl', 'baseline/screen:1')
1851   y = y + Editor_state.line_height
1852   App.screen.check(y, 'mno', 'baseline/screen:2')
1853   -- after hitting backspace the screen scrolls up by one screen line
1854   edit.run_after_keychord(Editor_state, 'backspace')
1855   y = Editor_state.top
1856   App.screen.check(y, 'ghij', 'screen:1')
1857   y = y + Editor_state.line_height
1858   App.screen.check(y, 'kl', 'screen:2')
1859   y = y + Editor_state.line_height
1860   App.screen.check(y, 'mno', 'screen:3')
1861   check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
1862   check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
1863   check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
1864   check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
1865 end
1866
1867 function test_backspace_past_line_boundary()
1868   -- position cursor at start of a (non-first) line
1869   App.screen.init{width=Editor_state.left+30, height=60}
1870   Editor_state = edit.initialize_test_state()
1871   Editor_state.lines = load_array{'abc', 'def'}
1872   Text.redraw_all(Editor_state)
1873   Editor_state.cursor1 = {line=2, pos=1}
1874   -- backspace joins with previous line
1875   edit.run_after_keychord(Editor_state, 'backspace')
1876   check_eq(Editor_state.lines[1].data, 'abcdef', 'check')
1877 end
1878
1879 -- some tests for operating over selections created using Shift- chords
1880 -- we're just testing delete_selection, and it works the same for all keys
1881
1882 function test_backspace_over_selection()
1883   -- select just one character within a line with cursor before selection
1884   App.screen.init{width=Editor_state.left+30, height=60}
1885   Editor_state = edit.initialize_test_state()
1886   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl', 'mno'}
1887   Text.redraw_all(Editor_state)
1888   Editor_state.cursor1 = {line=1, pos=1}
1889   Editor_state.selection1 = {line=1, pos=2}
1890   -- backspace deletes the selected character, even though it's after the cursor
1891   edit.run_after_keychord(Editor_state, 'backspace')
1892   check_eq(Editor_state.lines[1].data, 'bc', 'data')
1893   -- cursor (remains) at start of selection
1894   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1895   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1896   -- selection is cleared
1897   check_nil(Editor_state.selection1.line, 'selection')
1898 end
1899
1900 function test_backspace_over_selection_reverse()
1901   -- select just one character within a line with cursor after selection
1902   App.screen.init{width=Editor_state.left+30, height=60}
1903   Editor_state = edit.initialize_test_state()
1904   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl', 'mno'}
1905   Text.redraw_all(Editor_state)
1906   Editor_state.cursor1 = {line=1, pos=2}
1907   Editor_state.selection1 = {line=1, pos=1}
1908   -- backspace deletes the selected character
1909   edit.run_after_keychord(Editor_state, 'backspace')
1910   check_eq(Editor_state.lines[1].data, 'bc', 'data')
1911   -- cursor moves to start of selection
1912   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1913   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1914   -- selection is cleared
1915   check_nil(Editor_state.selection1.line, 'selection')
1916 end
1917
1918 function test_backspace_over_multiple_lines()
1919   -- select just one character within a line with cursor after selection
1920   App.screen.init{width=Editor_state.left+30, height=60}
1921   Editor_state = edit.initialize_test_state()
1922   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl', 'mno'}
1923   Text.redraw_all(Editor_state)
1924   Editor_state.cursor1 = {line=1, pos=2}
1925   Editor_state.selection1 = {line=4, pos=2}
1926   -- backspace deletes the region and joins the remaining portions of lines on either side
1927   edit.run_after_keychord(Editor_state, 'backspace')
1928   check_eq(Editor_state.lines[1].data, 'akl', 'data:1')
1929   check_eq(Editor_state.lines[2].data, 'mno', 'data:2')
1930   -- cursor remains at start of selection
1931   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1932   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
1933   -- selection is cleared
1934   check_nil(Editor_state.selection1.line, 'selection')
1935 end
1936
1937 function test_backspace_to_end_of_line()
1938   -- select region from cursor to end of line
1939   App.screen.init{width=Editor_state.left+30, height=60}
1940   Editor_state = edit.initialize_test_state()
1941   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl', 'mno'}
1942   Text.redraw_all(Editor_state)
1943   Editor_state.cursor1 = {line=1, pos=2}
1944   Editor_state.selection1 = {line=1, pos=4}
1945   -- backspace deletes rest of line without joining to any other line
1946   edit.run_after_keychord(Editor_state, 'backspace')
1947   check_eq(Editor_state.lines[1].data, 'a', 'data:1')
1948   check_eq(Editor_state.lines[2].data, 'def', 'data:2')
1949   -- cursor remains at start of selection
1950   check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
1951   check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
1952   -- selection is cleared
1953   check_nil(Editor_state.selection1.line, 'selection')
1954 end
1955
1956 function test_backspace_to_start_of_line()
1957   -- select region from cursor to start of line
1958   App.screen.init{width=Editor_state.left+30, height=60}
1959   Editor_state = edit.initialize_test_state()
1960   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl', 'mno'}
1961   Text.redraw_all(Editor_state)
1962   Editor_state.cursor1 = {line=2, pos=1}
1963   Editor_state.selection1 = {line=2, pos=3}
1964   -- backspace deletes beginning of line without joining to any other line
1965   edit.run_after_keychord(Editor_state, 'backspace')
1966   check_eq(Editor_state.lines[1].data, 'abc', 'data:1')
1967   check_eq(Editor_state.lines[2].data, 'f', 'data:2')
1968   -- cursor remains at start of selection
1969   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
1970   check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
1971   -- selection is cleared
1972   check_nil(Editor_state.selection1.line, 'selection')
1973 end
1974
1975 function test_undo_insert_text()
1976   App.screen.init{width=120, height=60}
1977   Editor_state = edit.initialize_test_state()
1978   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
1979   Text.redraw_all(Editor_state)
1980   Editor_state.cursor1 = {line=2, pos=4}
1981   Editor_state.screen_top1 = {line=1, pos=1}
1982   Editor_state.screen_bottom1 = {}
1983   -- insert a character
1984   edit.draw(Editor_state)
1985   edit.run_after_text_input(Editor_state, 'g')
1986   check_eq(Editor_state.cursor1.line, 2, 'baseline/cursor:line')
1987   check_eq(Editor_state.cursor1.pos, 5, 'baseline/cursor:pos')
1988   check_nil(Editor_state.selection1.line, 'baseline/selection:line')
1989   check_nil(Editor_state.selection1.pos, 'baseline/selection:pos')
1990   local y = Editor_state.top
1991   App.screen.check(y, 'abc', 'baseline/screen:1')
1992   y = y + Editor_state.line_height
1993   App.screen.check(y, 'defg', 'baseline/screen:2')
1994   y = y + Editor_state.line_height
1995   App.screen.check(y, 'xyz', 'baseline/screen:3')
1996   -- undo
1997   edit.run_after_keychord(Editor_state, 'C-z')
1998   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
1999   check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
2000   check_nil(Editor_state.selection1.line, 'selection:line')
2001   check_nil(Editor_state.selection1.pos, 'selection:pos')
2002   y = Editor_state.top
2003   App.screen.check(y, 'abc', 'screen:1')
2004   y = y + Editor_state.line_height
2005   App.screen.check(y, 'def', 'screen:2')
2006   y = y + Editor_state.line_height
2007   App.screen.check(y, 'xyz', 'screen:3')
2008 end
2009
2010 function test_undo_delete_text()
2011   App.screen.init{width=120, height=60}
2012   Editor_state = edit.initialize_test_state()
2013   Editor_state.lines = load_array{'abc', 'defg', 'xyz'}
2014   Text.redraw_all(Editor_state)
2015   Editor_state.cursor1 = {line=2, pos=5}
2016   Editor_state.screen_top1 = {line=1, pos=1}
2017   Editor_state.screen_bottom1 = {}
2018   -- delete a character
2019   edit.run_after_keychord(Editor_state, 'backspace')
2020   check_eq(Editor_state.cursor1.line, 2, 'baseline/cursor:line')
2021   check_eq(Editor_state.cursor1.pos, 4, 'baseline/cursor:pos')
2022   check_nil(Editor_state.selection1.line, 'baseline/selection:line')
2023   check_nil(Editor_state.selection1.pos, 'baseline/selection:pos')
2024   local y = Editor_state.top
2025   App.screen.check(y, 'abc', 'baseline/screen:1')
2026   y = y + Editor_state.line_height
2027   App.screen.check(y, 'def', 'baseline/screen:2')
2028   y = y + Editor_state.line_height
2029   App.screen.check(y, 'xyz', 'baseline/screen:3')
2030   -- undo
2031 --?   -- after undo, the backspaced key is selected
2032   edit.run_after_keychord(Editor_state, 'C-z')
2033   check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
2034   check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
2035   check_nil(Editor_state.selection1.line, 'selection:line')
2036   check_nil(Editor_state.selection1.pos, 'selection:pos')
2037 --?   check_eq(Editor_state.selection1.line, 2, 'selection:line')
2038 --?   check_eq(Editor_state.selection1.pos, 4, 'selection:pos')
2039   y = Editor_state.top
2040   App.screen.check(y, 'abc', 'screen:1')
2041   y = y + Editor_state.line_height
2042   App.screen.check(y, 'defg', 'screen:2')
2043   y = y + Editor_state.line_height
2044   App.screen.check(y, 'xyz', 'screen:3')
2045 end
2046
2047 function test_undo_restores_selection()
2048   -- display a line of text with some part selected
2049   App.screen.init{width=75, height=80}
2050   Editor_state = edit.initialize_test_state()
2051   Editor_state.lines = load_array{'abc'}
2052   Text.redraw_all(Editor_state)
2053   Editor_state.cursor1 = {line=1, pos=1}
2054   Editor_state.selection1 = {line=1, pos=2}
2055   Editor_state.screen_top1 = {line=1, pos=1}
2056   Editor_state.screen_bottom1 = {}
2057   edit.draw(Editor_state)
2058   -- delete selected text
2059   edit.run_after_text_input(Editor_state, 'x')
2060   check_eq(Editor_state.lines[1].data, 'xbc', 'baseline')
2061   check_nil(Editor_state.selection1.line, 'baseline:selection')
2062   -- undo
2063   edit.run_after_keychord(Editor_state, 'C-z')
2064   edit.run_after_keychord(Editor_state, 'C-z')
2065   -- selection is restored
2066   check_eq(Editor_state.selection1.line, 1, 'line')
2067   check_eq(Editor_state.selection1.pos, 2, 'pos')
2068 end
2069
2070 function test_search()
2071   App.screen.init{width=120, height=60}
2072   Editor_state = edit.initialize_test_state()
2073   Editor_state.lines = load_array{'```lines', '```', 'def', 'ghi', '’deg'}  -- contains unicode quote in final line
2074   Text.redraw_all(Editor_state)
2075   Editor_state.cursor1 = {line=1, pos=1}
2076   Editor_state.screen_top1 = {line=1, pos=1}
2077   Editor_state.screen_bottom1 = {}
2078   edit.draw(Editor_state)
2079   -- search for a string
2080   edit.run_after_keychord(Editor_state, 'C-f')
2081   edit.run_after_text_input(Editor_state, 'd')
2082   edit.run_after_keychord(Editor_state, 'return')
2083   check_eq(Editor_state.cursor1.line, 2, '1/cursor:line')
2084   check_eq(Editor_state.cursor1.pos, 1, '1/cursor:pos')
2085   -- reset cursor
2086   Editor_state.cursor1 = {line=1, pos=1}
2087   Editor_state.screen_top1 = {line=1, pos=1}
2088   -- search for second occurrence
2089   edit.run_after_keychord(Editor_state, 'C-f')
2090   edit.run_after_text_input(Editor_state, 'de')
2091   edit.run_after_keychord(Editor_state, 'down')
2092   edit.run_after_keychord(Editor_state, 'return')
2093   check_eq(Editor_state.cursor1.line, 4, '2/cursor:line')
2094   check_eq(Editor_state.cursor1.pos, 2, '2/cursor:pos')
2095 end
2096
2097 function test_search_upwards()
2098   App.screen.init{width=120, height=60}
2099   Editor_state = edit.initialize_test_state()
2100   Editor_state.lines = load_array{'’abc', 'abd'}  -- contains unicode quote
2101   Text.redraw_all(Editor_state)
2102   Editor_state.cursor1 = {line=2, pos=1}
2103   Editor_state.screen_top1 = {line=1, pos=1}
2104   Editor_state.screen_bottom1 = {}
2105   edit.draw(Editor_state)
2106   -- search for a string
2107   edit.run_after_keychord(Editor_state, 'C-f')
2108   edit.run_after_text_input(Editor_state, 'a')
2109   -- search for previous occurrence
2110   edit.run_after_keychord(Editor_state, 'up')
2111   check_eq(Editor_state.cursor1.line, 1, '2/cursor:line')
2112   check_eq(Editor_state.cursor1.pos, 2, '2/cursor:pos')
2113 end
2114
2115 function test_search_wrap()
2116   App.screen.init{width=120, height=60}
2117   Editor_state = edit.initialize_test_state()
2118   Editor_state.lines = load_array{'’abc', 'def'}  -- contains unicode quote in first line
2119   Text.redraw_all(Editor_state)
2120   Editor_state.cursor1 = {line=2, pos=1}
2121   Editor_state.screen_top1 = {line=1, pos=1}
2122   Editor_state.screen_bottom1 = {}
2123   edit.draw(Editor_state)
2124   -- search for a string
2125   edit.run_after_keychord(Editor_state, 'C-f')
2126   edit.run_after_text_input(Editor_state, 'a')
2127   edit.run_after_keychord(Editor_state, 'return')
2128   -- cursor wraps
2129   check_eq(Editor_state.cursor1.line, 1, '1/cursor:line')
2130   check_eq(Editor_state.cursor1.pos, 2, '1/cursor:pos')
2131 end
2132
2133 function test_search_wrap_upwards()
2134   App.screen.init{width=120, height=60}
2135   Editor_state = edit.initialize_test_state()
2136   Editor_state.lines = load_array{'abc ’abd'}  -- contains unicode quote
2137   Text.redraw_all(Editor_state)
2138   Editor_state.cursor1 = {line=1, pos=1}
2139   Editor_state.screen_top1 = {line=1, pos=1}
2140   Editor_state.screen_bottom1 = {}
2141   edit.draw(Editor_state)
2142   -- search upwards for a string
2143   edit.run_after_keychord(Editor_state, 'C-f')
2144   edit.run_after_text_input(Editor_state, 'a')
2145   edit.run_after_keychord(Editor_state, 'up')
2146   -- cursor wraps
2147   check_eq(Editor_state.cursor1.line, 1, '1/cursor:line')
2148   check_eq(Editor_state.cursor1.pos, 6, '1/cursor:pos')
2149 end