aboutsummaryrefslogtreecommitdiff
path: root/test/unit/marktree_spec.lua
blob: b0a861727d5b200e0f5f4d631a3ce46cd8dd3b5a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
local helpers = require('test.unit.helpers')(after_each)
local itp = helpers.gen_itp(it)

local ffi = helpers.ffi
local eq = helpers.eq
local ok = helpers.ok

local lib = helpers.cimport('./src/nvim/marktree.h')

local function tablelength(t)
  local count = 0
  for _ in pairs(t) do
    count = count + 1
  end
  return count
end

local function pos_leq(a, b)
  return a[1] < b[1] or (a[1] == b[1] and a[2] <= b[2])
end

-- Checks that shadow and tree is consistent, and optionally
-- return the order
local function shadoworder(tree, shadow, iter, giveorder)
  ok(iter ~= nil)
  local status = lib.marktree_itr_first(tree, iter)
  local count = 0
  local pos2id, id2pos = {}, {}
  local last
  if not status and next(shadow) == nil then
    return pos2id, id2pos
  end
  repeat
    local mark = lib.marktree_itr_current(iter)
    local id = tonumber(mark.id)
    local spos = shadow[id]
    eq(mark.pos.row, spos[1], mark.id)
    eq(mark.pos.col, spos[2], mark.id)
    if lib.mt_right_test(mark) ~= spos[3] then
      error('invalid gravity for ' .. id .. ':(' .. mark.pos.row .. ', ' .. mark.pos.col .. ')')
    end
    if count > 0 then
      if not pos_leq(last, spos) then
        error('DISORDER')
      end
    end
    count = count + 1
    last = spos
    if giveorder then
      pos2id[count] = id
      id2pos[id] = count
    end
  until not lib.marktree_itr_next(tree, iter)
  local shadowlen = tablelength(shadow)
  if shadowlen ~= count then
    error('missed some keys? (shadow ' .. shadowlen .. ', tree ' .. count .. ')')
  end
  return id2pos, pos2id
end

local function shadowsplice(shadow, start, old_extent, new_extent)
  local old_end = {
    start[1] + old_extent[1],
    (old_extent[1] == 0 and start[2] or 0) + old_extent[2],
  }
  local new_end = {
    start[1] + new_extent[1],
    (new_extent[1] == 0 and start[2] or 0) + new_extent[2],
  }
  local delta = { new_end[1] - old_end[1], new_end[2] - old_end[2] }
  for _, pos in pairs(shadow) do
    if pos_leq(start, pos) then
      if pos_leq(pos, old_end) then
        -- delete region
        if pos[3] then -- right gravity
          pos[1], pos[2] = new_end[1], new_end[2]
        else
          pos[1], pos[2] = start[1], start[2]
        end
      else
        if pos[1] == old_end[1] then
          pos[2] = pos[2] + delta[2]
        end
        pos[1] = pos[1] + delta[1]
      end
    end
  end
end

local function dosplice(tree, shadow, start, old, new)
  lib.marktree_splice(tree, start[1], start[2], old[1], old[2], new[1], new[2])
  shadowsplice(shadow, start, old, new)
end

local ns = 10
local last_id = nil

local function put(tree, row, col, gravity, end_row, end_col, end_gravity)
  last_id = last_id + 1
  local my_id = last_id

  end_row = end_row or -1
  end_col = end_col or -1
  end_gravity = end_gravity or false

  lib.marktree_put_test(tree, ns, my_id, row, col, gravity, end_row, end_col, end_gravity, false)
  return my_id
end

local function put_meta(tree, row, col, gravitate, meta)
  last_id = last_id + 1
  local my_id = last_id

  lib.marktree_put_test(tree, ns, my_id, row, col, gravitate, -1, -1, false, meta)
  return my_id
end

describe('marktree', function()
  before_each(function()
    last_id = 0
  end)

  itp('works', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit
    local shadow = {}
    local iter = ffi.new('MarkTreeIter[1]')
    local iter2 = ffi.new('MarkTreeIter[1]')

    for i = 1, 100 do
      for j = 1, 100 do
        local gravitate = (i % 2) > 0
        local id = put(tree, j, i, gravitate)
        ok(id > 0)
        eq(nil, shadow[id])
        shadow[id] = { j, i, gravitate }
      end
      -- checking every insert is too slow, but this is ok
      lib.marktree_check(tree)
    end

    -- ss = lib.mt_inspect_rec(tree)
    -- io.stdout:write(ffi.string(ss))
    -- io.stdout:flush()

    local id2pos, pos2id = shadoworder(tree, shadow, iter)
    eq({}, pos2id) -- not set if not requested
    eq({}, id2pos)

    for i, ipos in pairs(shadow) do
      local p = lib.marktree_lookup_ns(tree, ns, i, false, iter)
      eq(ipos[1], p.pos.row)
      eq(ipos[2], p.pos.col)
      local k = lib.marktree_itr_current(iter)
      eq(ipos[1], k.pos.row)
      eq(ipos[2], k.pos.col, ipos[1])
      lib.marktree_itr_next(tree, iter)
      -- TODO(bfredl): use id2pos to check neighbour?
      -- local k2 = lib.marktree_itr_current(iter)
    end

    for i, ipos in pairs(shadow) do
      lib.marktree_itr_get(tree, ipos[1], ipos[2], iter)
      local k = lib.marktree_itr_current(iter)
      eq(i, tonumber(k.id))
      eq(ipos[1], k.pos.row)
      eq(ipos[2], k.pos.col)
    end

    ok(lib.marktree_itr_first(tree, iter))
    local del = lib.marktree_itr_current(iter)

    lib.marktree_del_itr(tree, iter, false)
    shadow[tonumber(del.id)] = nil
    shadoworder(tree, shadow, iter)

    for _, ci in ipairs({ 0, -1, 1, -2, 2, -10, 10 }) do
      for i = 1, 100 do
        lib.marktree_itr_get(tree, i, 50 + ci, iter)
        local k = lib.marktree_itr_current(iter)
        local id = tonumber(k.id)
        eq(shadow[id][1], k.pos.row)
        eq(shadow[id][2], k.pos.col)
        lib.marktree_del_itr(tree, iter, false)
        shadow[id] = nil
      end
      lib.marktree_check(tree)
      shadoworder(tree, shadow, iter)
    end

    -- NB: this is quite rudimentary. We rely on
    -- functional tests exercising splicing quite a bit
    lib.marktree_check(tree)
    dosplice(tree, shadow, { 2, 2 }, { 0, 5 }, { 1, 2 })
    lib.marktree_check(tree)
    shadoworder(tree, shadow, iter)
    dosplice(tree, shadow, { 30, 2 }, { 30, 5 }, { 1, 2 })
    lib.marktree_check(tree)
    shadoworder(tree, shadow, iter)

    dosplice(tree, shadow, { 5, 3 }, { 0, 2 }, { 0, 5 })
    shadoworder(tree, shadow, iter)
    lib.marktree_check(tree)

    -- build then burn (HOORAY! HOORAY!)
    while next(shadow) do
      lib.marktree_itr_first(tree, iter)
      -- delete every other key for fun and profit
      while true do
        local k = lib.marktree_itr_current(iter)
        lib.marktree_del_itr(tree, iter, false)
        ok(shadow[tonumber(k.id)] ~= nil)
        shadow[tonumber(k.id)] = nil
        local stat = lib.marktree_itr_next(tree, iter)
        if not stat then
          break
        end
      end
      lib.marktree_check(tree)
      shadoworder(tree, shadow, iter2)
    end

    -- Check iterator validity for 2 specific edge cases:
    -- https://github.com/neovim/neovim/pull/14719
    lib.marktree_clear(tree)
    for i = 1, 20 do
      put(tree, i, i, false)
    end

    lib.marktree_itr_get(tree, 10, 10, iter)
    lib.marktree_del_itr(tree, iter, false)
    eq(11, iter[0].x.key[iter[0].i].pos.col)

    lib.marktree_itr_get(tree, 11, 11, iter)
    lib.marktree_del_itr(tree, iter, false)
    eq(12, iter[0].x.key[iter[0].i].pos.col)
  end)

  itp("'intersect_mov' function works correctly", function()
    local function mov(x, y, w)
      local xa = ffi.new('uint64_t[?]', #x)
      for i, xi in ipairs(x) do
        xa[i - 1] = xi
      end
      local ya = ffi.new('uint64_t[?]', #y)
      for i, yi in ipairs(y) do
        ya[i - 1] = yi
      end
      local wa = ffi.new('uint64_t[?]', #w)
      for i, wi in ipairs(w) do
        wa[i - 1] = wi
      end

      local dummy_size = #x + #y + #w
      local wouta = ffi.new('uint64_t[?]', dummy_size)
      local douta = ffi.new('uint64_t[?]', dummy_size)
      local wsize = ffi.new('size_t[1]')
      wsize[0] = dummy_size
      local dsize = ffi.new('size_t[1]')
      dsize[0] = dummy_size

      local status = lib.intersect_mov_test(xa, #x, ya, #y, wa, #w, wouta, wsize, douta, dsize)
      if status == 0 then
        error 'wowza'
      end

      local wout, dout = {}, {}
      for i = 0, tonumber(wsize[0]) - 1 do
        table.insert(wout, tonumber(wouta[i]))
      end
      for i = 0, tonumber(dsize[0]) - 1 do
        table.insert(dout, tonumber(douta[i]))
      end
      return { wout, dout }
    end

    eq({ {}, {} }, mov({}, { 2, 3 }, { 2, 3 }))
    eq({ { 2, 3 }, {} }, mov({}, {}, { 2, 3 }))
    eq({ { 2, 3 }, {} }, mov({ 2, 3 }, {}, {}))
    eq({ {}, { 2, 3 } }, mov({}, { 2, 3 }, {}))

    eq({ { 1, 5 }, {} }, mov({ 1, 2, 5 }, { 2, 3 }, { 3 }))
    eq({ { 1, 2 }, {} }, mov({ 1, 2, 5 }, { 5, 10 }, { 10 }))
    eq({ { 1, 2 }, { 5 } }, mov({ 1, 2 }, { 5, 10 }, { 10 }))
    eq({ { 1, 3, 5, 7, 9 }, { 2, 4, 6, 8, 10 } }, mov({ 1, 3, 5, 7, 9 }, { 2, 4, 6, 8, 10 }, {}))
    eq({ { 1, 3, 5, 7, 9 }, { 2, 6, 10 } }, mov({ 1, 3, 5, 7, 9 }, { 2, 4, 6, 8, 10 }, { 4, 8 }))
    eq({ { 1, 4, 7 }, { 2, 5, 8 } }, mov({ 1, 3, 4, 6, 7, 9 }, { 2, 3, 5, 6, 8, 9 }, {}))
    eq({ { 1, 4, 7 }, {} }, mov({ 1, 3, 4, 6, 7, 9 }, { 2, 3, 5, 6, 8, 9 }, { 2, 5, 8 }))
    eq(
      { { 0, 1, 4, 7, 10 }, {} },
      mov({ 1, 3, 4, 6, 7, 9 }, { 2, 3, 5, 6, 8, 9 }, { 0, 2, 5, 8, 10 })
    )
  end)

  local function check_intersections(tree)
    lib.marktree_check(tree)
    -- to debug stuff disable this branch
    if true == true then
      ok(lib.marktree_check_intersections(tree))
      return
    end

    local str1 = lib.mt_inspect(tree, true, true)
    local dot1 = ffi.string(str1.data, str1.size)

    local val = lib.marktree_check_intersections(tree)
    if not val then
      local str2 = lib.mt_inspect(tree, true, true)
      local dot2 = ffi.string(str2.data, str2.size)
      print('actual:\n\n' .. 'Xafile.dot' .. '\n\nexpected:\n\n' .. 'Xefile.dot' .. '\n')
      print('nivå', tree[0].root.level)
      io.stdout:flush()
      local afil = io.open('Xafile.dot', 'wb')
      afil:write(dot1)
      afil:close()
      local efil = io.open('Xefile.dot', 'wb')
      efil:write(dot2)
      efil:close()
      ok(false)
    else
      ffi.C.xfree(str1.data)
    end
  end

  itp('works with intersections', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit

    local ids = {}

    for i = 1, 80 do
      table.insert(ids, put(tree, 1, i, false, 2, 100 - i, false))
      check_intersections(tree)
    end
    for i = 1, 80 do
      lib.marktree_del_pair_test(tree, ns, ids[i])
      check_intersections(tree)
    end
    ids = {}

    for i = 1, 80 do
      table.insert(ids, put(tree, 1, i, false, 2, 100 - i, false))
      check_intersections(tree)
    end

    for i = 1, 10 do
      for j = 1, 8 do
        local ival = (j - 1) * 10 + i
        lib.marktree_del_pair_test(tree, ns, ids[ival])
        check_intersections(tree)
      end
    end
  end)

  itp('works with intersections with a big tree', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit

    local ids = {}

    for i = 1, 1000 do
      table.insert(ids, put(tree, 1, i, false, 2, 1000 - i, false))
      if i % 10 == 1 then
        check_intersections(tree)
      end
    end

    check_intersections(tree)
    eq(2000, tree[0].n_keys)
    ok(tree[0].root.level >= 2)

    local iter = ffi.new('MarkTreeIter[1]')

    local k = 0
    for i = 1, 20 do
      for j = 1, 50 do
        k = k + 1
        local ival = (j - 1) * 20 + i
        if false == true then -- if there actually is a failure, this branch will fail out at the actual spot of the error
          lib.marktree_lookup_ns(tree, ns, ids[ival], false, iter)
          lib.marktree_del_itr(tree, iter, false)
          check_intersections(tree)

          lib.marktree_lookup_ns(tree, ns, ids[ival], true, iter)
          lib.marktree_del_itr(tree, iter, false)
          check_intersections(tree)
        else
          lib.marktree_del_pair_test(tree, ns, ids[ival])
          if k % 5 == 1 then
            check_intersections(tree)
          end
        end
      end
    end

    eq(0, tree[0].n_keys)
  end)

  itp('works with intersections and marktree_splice', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit

    for i = 1, 1000 do
      put(tree, 1, i, false, 2, 1000 - i, false)
      if i % 10 == 1 then
        check_intersections(tree)
      end
    end

    check_intersections(tree)
    eq(2000, tree[0].n_keys)
    ok(tree[0].root.level >= 2)

    for _ = 1, 10 do
      lib.marktree_splice(tree, 0, 0, 0, 100, 0, 0)
      check_intersections(tree)
    end
  end)

  itp('marktree_move should preserve key order', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit
    local iter = ffi.new('MarkTreeIter[1]')
    local ids = {}

    -- new index and old index look the same, but still have to move because
    -- pos will get updated
    table.insert(ids, put(tree, 1, 1, false, 1, 3, false))
    table.insert(ids, put(tree, 1, 3, false, 1, 3, false))
    table.insert(ids, put(tree, 1, 3, false, 1, 3, false))
    table.insert(ids, put(tree, 1, 3, false, 1, 3, false))

    lib.marktree_lookup_ns(tree, ns, ids[3], false, iter)
    lib.marktree_move(tree, iter, 1, 2)

    check_intersections(tree)
  end)

  itp('works with intersections and marktree_move', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit

    local ids = {}

    for i = 1, 1000 do
      table.insert(ids, put(tree, 1, i, false, 2, 1000 - i, false))
      if i % 10 == 1 then
        check_intersections(tree)
      end
    end

    local iter = ffi.new('MarkTreeIter[1]')
    for i = 1, 1000 do
      local which = i % 2
      lib.marktree_lookup_ns(tree, ns, ids[i], which, iter)
      lib.marktree_move(tree, iter, 1 + which, 500 + i)
      if i % 10 == 1 then
        check_intersections(tree)
      end
    end
  end)

  itp('works with intersections with a even bigger tree', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit

    local ids = {}

    -- too much overhead on ASAN
    local size_factor = helpers.is_asan() and 3 or 10

    local at_row = {}
    for i = 1, 10 do
      at_row[i] = {}
    end

    local size = 1000 * size_factor
    local k = 1
    while k <= size do
      for row1 = 1, 9 do
        for row2 = row1, 10 do -- note row2 can be == row1, leads to empty ranges being tested when k > size/2
          if k > size then
            break
          end
          local id = put(tree, row1, k, false, row2, size - k, false)
          table.insert(ids, id)
          for i = row1 + 1, row2 do
            table.insert(at_row[i], id)
          end
          --if tree[0].root.level == 4 then error("kk"..k) end
          if k % 100 * size_factor == 1 or (k < 2000 and k % 100 == 1) then
            check_intersections(tree)
          end
          k = k + 1
        end
      end
    end

    eq(2 * size, tree[0].n_keys)
    ok(tree[0].root.level >= 3)
    check_intersections(tree)

    local iter = ffi.new('MarkTreeIter[1]')
    local pair = ffi.new('MTPair[1]')
    for i = 1, 10 do
      -- use array as set and not {[id]=true} map, to detect duplicates
      local set = {}
      eq(true, ffi.C.marktree_itr_get_overlap(tree, i, 0, iter))
      while ffi.C.marktree_itr_step_overlap(tree, iter, pair) do
        local id = tonumber(pair[0].start.id)
        table.insert(set, id)
      end
      table.sort(set)
      eq(at_row[i], set)
    end

    k = 0
    for i = 1, 100 do
      for j = 1, (10 * size_factor) do
        k = k + 1
        local ival = (j - 1) * 100 + i
        lib.marktree_del_pair_test(tree, ns, ids[ival])
        -- just a few stickprov, if there is trouble we need to check
        -- everyone using the code in the "big tree" case above
        if k % 100 * size_factor == 0 or (k > 3000 and k % 200 == 0) then
          check_intersections(tree)
        end
      end
    end

    eq(0, tree[0].n_keys)
  end)

  itp('works with intersections with a even bigger tree and splice', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit

    -- too much overhead on ASAN
    local size_factor = helpers.is_asan() and 3 or 10

    local at_row = {}
    for i = 1, 10 do
      at_row[i] = {}
    end

    local size = 1000 * size_factor
    local k = 1
    while k <= size do
      for row1 = 1, 9 do
        for row2 = row1, 10 do -- note row2 can be == row1, leads to empty ranges being tested when k > size/2
          if k > size then
            break
          end
          local id = put(tree, row1, k, false, row2, size - k, false)
          for i = row1 + 1, row2 do
            table.insert(at_row[i], id)
          end
          --if tree[0].root.level == 4 then error("kk"..k) end
          if k % 100 * size_factor == 1 or (k < 2000 and k % 100 == 1) then
            check_intersections(tree)
          end
          k = k + 1
        end
      end
    end

    eq(2 * size, tree[0].n_keys)
    ok(tree[0].root.level >= 3)
    check_intersections(tree)

    for _ = 1, 10 do
      for j = 3, 8 do
        lib.marktree_splice(tree, j, 0, 0, 200, 0, 0)
        check_intersections(tree)
      end
    end
  end)

  itp('works with meta counts', function()
    local tree = ffi.new('MarkTree[1]') -- zero initialized by luajit

    -- add
    local shadow = {}
    for i = 1, 100 do
      for j = 1, 100 do
        local gravitate = (i % 2) > 0
        local inline = (j == 3 or j == 50 or j == 51 or j == 55) and i % 11 == 1
        inline = inline or ((j >= 80 and j < 85) and i % 3 == 1)
        local id = put_meta(tree, j, i, gravitate, inline)
        if inline then
          shadow[id] = { j, i, gravitate }
        end
      end
      -- checking every insert is too slow, but this is ok
      lib.marktree_check(tree)
    end

    lib.marktree_check(tree)
    local iter = ffi.new('MarkTreeIter[1]')
    local filter = ffi.new('uint32_t[4]')
    filter[0] = -1
    ok(lib.marktree_itr_get_filter(tree, 0, 0, 101, 0, filter, iter))
    local seen = {}
    repeat
      local mark = lib.marktree_itr_current(iter)
      eq(nil, seen[mark.id])
      seen[mark.id] = true
      eq(mark.pos.row, shadow[mark.id][1])
      eq(mark.pos.col, shadow[mark.id][2])
    until not lib.marktree_itr_next_filter(tree, iter, 101, 0, filter)
    eq(tablelength(seen), tablelength(shadow))

    -- test skipping subtrees to find the filtered mark at line 50
    for i = 4, 50 do
      ok(lib.marktree_itr_get_filter(tree, i, 0, 60, 0, filter, iter))
      local mark = lib.marktree_itr_current(iter)
      eq({ 50, 50, 1 }, { mark.id, mark.pos.row, mark.pos.col })
    end

    -- delete
    for id = 1, 10000, 2 do
      lib.marktree_lookup_ns(tree, ns, id, false, iter)
      if shadow[id] then
        local mark = lib.marktree_itr_current(iter)
        eq(mark.pos.row, shadow[id][1])
        eq(mark.pos.col, shadow[id][2])
        shadow[id] = nil
      end
      lib.marktree_del_itr(tree, iter, false)
      if id % 100 == 1 then
        lib.marktree_check(tree)
      end
    end

    -- Splice!
    dosplice(tree, shadow, { 82, 0 }, { 0, 50 }, { 0, 0 })
    lib.marktree_check(tree)

    dosplice(tree, shadow, { 81, 50 }, { 2, 50 }, { 1, 0 })
    lib.marktree_check(tree)

    dosplice(tree, shadow, { 2, 50 }, { 1, 50 }, { 0, 10 })
    lib.marktree_check(tree)

    ok(lib.marktree_itr_get_filter(tree, 0, 0, 101, 0, filter, iter))
    seen = {}
    repeat
      local mark = lib.marktree_itr_current(iter)
      eq(nil, seen[mark.id])
      seen[mark.id] = true
      eq(mark.pos.row, shadow[mark.id][1])
      eq(mark.pos.col, shadow[mark.id][2])
    until not lib.marktree_itr_next_filter(tree, iter, 101, 0, filter)
    eq(tablelength(seen), tablelength(shadow))
  end)
end)