Merge #7917 'API: buffer updates'

1 files changed, 743 insertions, 0 deletions

diff --git a/test/functional/api/buffer_updates_spec.lua b/test/functional/api/buffer_updates_spec.lua
new file mode 100644
index 0000000000..6da790b871
--- /dev/null
+++ b/test/functional/api/buffer_updates_spec.lua
@@ -0,0 +1,743 @@
+local helpers = require('test.functional.helpers')(after_each)
+local eq, ok = helpers.eq, helpers.ok
+local buffer, command, eval, nvim, next_msg = helpers.buffer,
+  helpers.command, helpers.eval, helpers.nvim, helpers.next_msg
+local expect_err = helpers.expect_err
+local write_file = helpers.write_file
+
+local origlines = {"original line 1",
+                   "original line 2",
+                   "original line 3",
+                   "original line 4",
+                   "original line 5",
+                   "original line 6"}
+
+local function expectn(name, args)
+  -- expect the next message to be the specified notification event
+  eq({'notification', name, args}, next_msg())
+end
+
+local function sendkeys(keys)
+  nvim('input', keys)
+  -- give nvim some time to process msgpack requests before possibly sending
+  -- more key presses - otherwise they all pile up in the queue and get
+  -- processed at once
+  local ntime = os.clock() + 0.1
+  repeat until os.clock() > ntime
+end
+
+local function open(activate, lines)
+  local filename = helpers.tmpname()
+  write_file(filename, table.concat(lines, "\n").."\n", true)
+  command('edit ' .. filename)
+  local b = nvim('get_current_buf')
+  -- what is the value of b:changedtick?
+  local tick = eval('b:changedtick')
+
+  -- Enable buffer events, ensure that the nvim_buf_lines_event messages
+  -- arrive as expected
+  if activate then
+    local firstline = 0
+    ok(buffer('attach', b, true, {}))
+    expectn('nvim_buf_lines_event', {b, tick, firstline, -1, lines, false})
+  end
+
+  return b, tick, filename
+end
+
+local function editoriginal(activate, lines)
+  if not lines then
+    lines = origlines
+  end
+  -- load up the file with the correct contents
+  helpers.clear()
+  return open(activate, lines)
+end
+
+local function reopen(buf, expectedlines)
+  ok(buffer('detach', buf))
+  expectn('nvim_buf_detach_event', {buf})
+  -- for some reason the :edit! increments tick by 2
+  command('edit!')
+  local tick = eval('b:changedtick')
+  ok(buffer('attach', buf, true, {}))
+  local firstline = 0
+  expectn('nvim_buf_lines_event', {buf, tick, firstline, -1, expectedlines, false})
+  command('normal! gg')
+  return tick
+end
+
+local function reopenwithfolds(b)
+  -- discard any changes to the buffer
+  local tick = reopen(b, origlines)
+
+  -- use markers for folds, make all folds open by default
+  command('setlocal foldmethod=marker foldlevel=20')
+
+  -- add a fold
+  command('2,4fold')
+  tick = tick + 1
+  expectn('nvim_buf_lines_event', {b, tick, 1, 4, {'original line 2/*{{{*/',
+                                          'original line 3',
+                                          'original line 4/*}}}*/'}, false})
+  -- make a new fold that wraps lines 1-6
+  command('1,6fold')
+  tick = tick + 1
+  expectn('nvim_buf_lines_event', {b, tick, 0, 6, {'original line 1/*{{{*/',
+                                          'original line 2/*{{{*/',
+                                          'original line 3',
+                                          'original line 4/*}}}*/',
+                                          'original line 5',
+                                          'original line 6/*}}}*/'}, false})
+  return tick
+end
+
+describe('API: buffer events:', function()
+  it('when lines are added', function()
+    local b, tick = editoriginal(true)
+
+    -- add a new line at the start of the buffer
+    command('normal! GyyggP')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 0, {'original line 6'}, false})
+
+    -- add multiple lines at the start of the file
+    command('normal! GkkyGggP')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 0, {'original line 4',
+                                           'original line 5',
+                                           'original line 6'}, false})
+
+    -- add one line to the middle of the file, several times
+    command('normal! ggYjjp')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 3, {'original line 4'}, false})
+    command('normal! p')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 4, 4, {'original line 4'}, false})
+    command('normal! p')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 5, 5, {'original line 4'}, false})
+
+    -- add multiple lines to the middle of the file
+    command('normal! gg4Yjjp')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 3, {'original line 4',
+                                           'original line 5',
+                                           'original line 6',
+                                           'original line 4'}, false})
+
+    -- add one line to the end of the file
+    command('normal! ggYGp')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 17, 17, {'original line 4'}, false})
+
+    -- add one line to the end of the file, several times
+    command('normal! ggYGppp')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 18, 18, {'original line 4'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 19, 19, {'original line 4'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 20, 20, {'original line 4'}, false})
+
+    -- add several lines to the end of the file, several times
+    command('normal! gg4YGp')
+    command('normal! Gp')
+    command('normal! Gp')
+    local firstfour = {'original line 4',
+                 'original line 5',
+                 'original line 6',
+                 'original line 4'}
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 21, 21, firstfour, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 25, 25, firstfour, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 29, 29, firstfour, false})
+
+    -- create a new empty buffer and wipe out the old one ... this will
+    -- turn off buffer events
+    command('enew!')
+    expectn('nvim_buf_detach_event', {b})
+
+    -- add a line at the start of an empty file
+    command('enew')
+    tick = eval('b:changedtick')
+    local b2 = nvim('get_current_buf')
+    ok(buffer('attach', b2, true, {}))
+    expectn('nvim_buf_lines_event', {b2, tick, 0, -1, {""}, false})
+    eval('append(0, ["new line 1"])')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b2, tick, 0, 0, {'new line 1'}, false})
+
+    -- turn off buffer events manually
+    buffer('detach', b2)
+    expectn('nvim_buf_detach_event', {b2})
+
+    -- add multiple lines to a blank file
+    command('enew!')
+    local b3 = nvim('get_current_buf')
+    ok(buffer('attach', b3, true, {}))
+    tick = eval('b:changedtick')
+    expectn('nvim_buf_lines_event', {b3, tick, 0, -1, {""}, false})
+    eval('append(0, ["new line 1", "new line 2", "new line 3"])')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b3, tick, 0, 0, {'new line 1',
+                                            'new line 2',
+                                            'new line 3'}, false})
+
+    -- use the API itself to add a line to the start of the buffer
+    buffer('set_lines', b3, 0, 0, true, {'New First Line'})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b3, tick, 0, 0, {"New First Line"}, false})
+  end)
+
+  it('when lines are removed', function()
+    local b, tick = editoriginal(true)
+
+    -- remove one line from start of file
+    command('normal! dd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {}, false})
+
+    -- remove multiple lines from the start of the file
+    command('normal! 4dd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 4, {}, false})
+
+    -- remove multiple lines from middle of file
+    tick = reopen(b, origlines)
+    command('normal! jj3dd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 2, 5, {}, false})
+
+    -- remove one line from the end of the file
+    tick = reopen(b, origlines)
+    command('normal! Gdd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 5, 6, {}, false})
+
+    -- remove multiple lines from the end of the file
+    tick = reopen(b, origlines)
+    command('normal! 4G3dd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 6, {}, false})
+
+    -- pretend to remove heaps lines from the end of the file but really
+    -- just remove two
+    tick = reopen(b, origlines)
+    command('normal! Gk5dd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 4, 6, {}, false})
+  end)
+
+  it('when text is changed', function()
+    local b, tick = editoriginal(true)
+
+    -- some normal text editing
+    command('normal! A555')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'original line 1555'}, false})
+    command('normal! jj8X')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 2, 3, {'origin3'}, false})
+
+    -- modify multiple lines at once using visual block mode
+    tick = reopen(b, origlines)
+    command('normal! jjw')
+    sendkeys('<C-v>jjllx')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event',
+            {b, tick, 2, 5, {'original e 3', 'original e 4', 'original e 5'}, false})
+
+    -- replace part of a line line using :s
+    tick = reopen(b, origlines)
+    command('3s/line 3/foo/')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 2, 3, {'original foo'}, false})
+
+    -- replace parts of several lines line using :s
+    tick = reopen(b, origlines)
+    command('%s/line [35]/foo/')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 2, 5, {'original foo',
+                                           'original line 4',
+                                           'original foo'}, false})
+
+    -- type text into the first line of a blank file, one character at a time
+    command('enew!')
+    tick = 2
+    expectn('nvim_buf_detach_event', {b})
+    local bnew = nvim('get_current_buf')
+    ok(buffer('attach', bnew, true, {}))
+    expectn('nvim_buf_lines_event', {bnew, tick, 0, -1, {''}, false})
+    sendkeys('i')
+    sendkeys('h')
+    sendkeys('e')
+    sendkeys('l')
+    sendkeys('l')
+    sendkeys('o\nworld')
+    expectn('nvim_buf_lines_event', {bnew, tick + 1, 0, 1, {'h'}, false})
+    expectn('nvim_buf_lines_event', {bnew, tick + 2, 0, 1, {'he'}, false})
+    expectn('nvim_buf_lines_event', {bnew, tick + 3, 0, 1, {'hel'}, false})
+    expectn('nvim_buf_lines_event', {bnew, tick + 4, 0, 1, {'hell'}, false})
+    expectn('nvim_buf_lines_event', {bnew, tick + 5, 0, 1, {'hello'}, false})
+    expectn('nvim_buf_lines_event', {bnew, tick + 6, 0, 1, {'hello', ''}, false})
+    expectn('nvim_buf_lines_event', {bnew, tick + 7, 1, 2, {'world'}, false})
+  end)
+
+  it('when lines are replaced', function()
+    local b, tick = editoriginal(true)
+
+    -- blast away parts of some lines with visual mode
+    command('normal! jjwvjjllx')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 2, 3, {'original '}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 4, {}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 4, {'e 5'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 2, 3, {'original e 5'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 4, {}, false})
+
+    -- blast away a few lines using :g
+    tick = reopen(b, origlines)
+    command('global/line [35]/delete')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 2, 3, {}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 4, {}, false})
+  end)
+
+  it('when lines are filtered', function()
+    -- Test filtering lines with !cat
+    local b, tick = editoriginal(true, {"A", "C", "E", "B", "D", "F"})
+
+    command('silent 2,5!cat')
+    -- the change comes through as two changes:
+    -- 1) addition of the new lines after the filtered lines
+    -- 2) removal of the original lines
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 5, 5, {"C", "E", "B", "D"}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 5, {}, false})
+  end)
+
+  it('when you use "o"', function()
+    local b, tick = editoriginal(true, {'AAA', 'BBB'})
+    command('set noautoindent nosmartindent')
+
+    -- use 'o' to start a new line from a line with no indent
+    command('normal! o')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 1, {""}, false})
+
+    -- undo the change, indent line 1 a bit, and try again
+    command('undo')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 2, {}, false})
+    tick = tick + 1
+    expectn('nvim_buf_changedtick_event', {b, tick})
+    command('set autoindent')
+    command('normal! >>')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {"\tAAA"}, false})
+    command('normal! ommm')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 1, {"\t"}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 2, {"\tmmm"}, false})
+
+    -- undo the change, and try again with 'O'
+    command('undo')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 2, {'\t'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 2, {}, false})
+    tick = tick + 1
+    expectn('nvim_buf_changedtick_event', {b, tick})
+    command('normal! ggOmmm')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 0, {"\t"}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {"\tmmm"}, false})
+  end)
+
+  it('deactivates if the buffer is changed externally', function()
+    -- Test changing file from outside vim and reloading using :edit
+    local lines = {"Line 1", "Line 2"};
+    local b, tick, filename = editoriginal(true, lines)
+
+    command('normal! x')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'ine 1'}, false})
+    command('undo')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'Line 1'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_changedtick_event', {b, tick})
+
+    -- change the file directly
+    write_file(filename, "another line\n", true, true)
+
+    -- reopen the file and watch buffer events shut down
+    command('edit')
+    expectn('nvim_buf_detach_event', {b})
+  end)
+
+  it('channel can watch many buffers at once', function()
+    -- edit 3 buffers, make sure they all have windows visible so that when we
+    -- move between buffers, none of them are unloaded
+    local b1, tick1 = editoriginal(true, {'A1', 'A2'})
+    local b1nr = eval('bufnr("")')
+    command('split')
+    local b2, tick2 = open(true, {'B1', 'B2'})
+    local b2nr = eval('bufnr("")')
+    command('split')
+    local b3, tick3 = open(true, {'C1', 'C2'})
+    local b3nr = eval('bufnr("")')
+
+    -- make a new window for moving between buffers
+    command('split')
+
+    command('b'..b1nr)
+    command('normal! x')
+    tick1 = tick1 + 1
+    expectn('nvim_buf_lines_event', {b1, tick1, 0, 1, {'1'}, false})
+    command('undo')
+    tick1 = tick1 + 1
+    expectn('nvim_buf_lines_event', {b1, tick1, 0, 1, {'A1'}, false})
+    tick1 = tick1 + 1
+    expectn('nvim_buf_changedtick_event', {b1, tick1})
+
+    command('b'..b2nr)
+    command('normal! x')
+    tick2 = tick2 + 1
+    expectn('nvim_buf_lines_event', {b2, tick2, 0, 1, {'1'}, false})
+    command('undo')
+    tick2 = tick2 + 1
+    expectn('nvim_buf_lines_event', {b2, tick2, 0, 1, {'B1'}, false})
+    tick2 = tick2 + 1
+    expectn('nvim_buf_changedtick_event', {b2, tick2})
+
+    command('b'..b3nr)
+    command('normal! x')
+    tick3 = tick3 + 1
+    expectn('nvim_buf_lines_event', {b3, tick3, 0, 1, {'1'}, false})
+    command('undo')
+    tick3 = tick3 + 1
+    expectn('nvim_buf_lines_event', {b3, tick3, 0, 1, {'C1'}, false})
+    tick3 = tick3 + 1
+    expectn('nvim_buf_changedtick_event', {b3, tick3})
+  end)
+
+  it('does not get confused if enabled/disabled many times',
+     function()
+    local channel = nvim('get_api_info')[1]
+    local b, tick = editoriginal(false)
+
+    -- Enable buffer events many times.
+    ok(buffer('attach', b, true, {}))
+    ok(buffer('attach', b, true, {}))
+    ok(buffer('attach', b, true, {}))
+    ok(buffer('attach', b, true, {}))
+    ok(buffer('attach', b, true, {}))
+    expectn('nvim_buf_lines_event', {b, tick, 0, -1, origlines, false})
+    eval('rpcnotify('..channel..', "Hello There")')
+    expectn('Hello There', {})
+
+    -- Disable buffer events many times.
+    ok(buffer('detach', b))
+    ok(buffer('detach', b))
+    ok(buffer('detach', b))
+    ok(buffer('detach', b))
+    ok(buffer('detach', b))
+    expectn('nvim_buf_detach_event', {b})
+    eval('rpcnotify('..channel..', "Hello Again")')
+    expectn('Hello Again', {})
+  end)
+
+  it('can notify several channels at once', function()
+    helpers.clear()
+
+    -- create several new sessions, in addition to our main API
+    local sessions = {}
+    local pipe = helpers.new_pipename()
+    eval("serverstart('"..pipe.."')")
+    sessions[1] = helpers.connect(pipe)
+    sessions[2] = helpers.connect(pipe)
+    sessions[3] = helpers.connect(pipe)
+
+    local function request(sessionnr, method, ...)
+      local status, rv = sessions[sessionnr]:request(method, ...)
+      if not status then
+        error(rv[2])
+      end
+      return rv
+    end
+
+    local function wantn(sessionid, name, args)
+      local session = sessions[sessionid]
+      eq({'notification', name, args}, session:next_message())
+    end
+
+    -- Edit a new file, but don't enable buffer events.
+    local lines = {'AAA', 'BBB'}
+    local b, tick = open(false, lines)
+
+    -- Enable buffer events for sessions 1, 2 and 3.
+    ok(request(1, 'nvim_buf_attach', b, true, {}))
+    ok(request(2, 'nvim_buf_attach', b, true, {}))
+    ok(request(3, 'nvim_buf_attach', b, true, {}))
+    wantn(1, 'nvim_buf_lines_event', {b, tick, 0, -1, lines, false})
+    wantn(2, 'nvim_buf_lines_event', {b, tick, 0, -1, lines, false})
+    wantn(3, 'nvim_buf_lines_event', {b, tick, 0, -1, lines, false})
+
+    -- Change the buffer.
+    command('normal! x')
+    tick = tick + 1
+    wantn(1, 'nvim_buf_lines_event', {b, tick, 0, 1, {'AA'}, false})
+    wantn(2, 'nvim_buf_lines_event', {b, tick, 0, 1, {'AA'}, false})
+    wantn(3, 'nvim_buf_lines_event', {b, tick, 0, 1, {'AA'}, false})
+
+    -- Stop watching on channel 1.
+    ok(request(1, 'nvim_buf_detach', b))
+    wantn(1, 'nvim_buf_detach_event', {b})
+
+    -- Undo the change to buffer 1.
+    command('undo')
+    tick = tick + 1
+    wantn(2, 'nvim_buf_lines_event', {b, tick, 0, 1, {'AAA'}, false})
+    wantn(3, 'nvim_buf_lines_event', {b, tick, 0, 1, {'AAA'}, false})
+    tick = tick + 1
+    wantn(2, 'nvim_buf_changedtick_event', {b, tick})
+    wantn(3, 'nvim_buf_changedtick_event', {b, tick})
+
+    -- make sure there are no other pending nvim_buf_lines_event messages going to
+    -- channel 1
+    local channel1 = request(1, 'nvim_get_api_info')[1]
+    eval('rpcnotify('..channel1..', "Hello")')
+    wantn(1, 'Hello', {})
+
+    -- close the buffer and channels 2 and 3 should get a nvim_buf_detach_event
+    -- notification
+    command('edit')
+    wantn(2, 'nvim_buf_detach_event', {b})
+    wantn(3, 'nvim_buf_detach_event', {b})
+
+    -- make sure there are no other pending nvim_buf_lines_event messages going to
+    -- channel 1
+    channel1 = request(1, 'nvim_get_api_info')[1]
+    eval('rpcnotify('..channel1..', "Hello Again")')
+    wantn(1, 'Hello Again', {})
+  end)
+
+  it('works with :diffput and :diffget', function()
+    if os.getenv("APPVEYOR") then
+      pending("Fails on appveyor for some reason.", function() end)
+    end
+
+    local b1, tick1 = editoriginal(true, {"AAA", "BBB"})
+    local channel = nvim('get_api_info')[1]
+    command('diffthis')
+    command('rightbelow vsplit')
+    local b2, tick2 = open(true, {"BBB", "CCC"})
+    command('diffthis')
+    -- go back to first buffer, and push the 'AAA' line to the second buffer
+    command('1wincmd w')
+    command('normal! gg')
+    command('diffput')
+    tick2 = tick2 + 1
+    expectn('nvim_buf_lines_event', {b2, tick2, 0, 0, {"AAA"}, false})
+
+    -- use :diffget to grab the other change from buffer 2
+    command('normal! G')
+    command('diffget')
+    tick1 = tick1 + 1
+    expectn('nvim_buf_lines_event', {b1, tick1, 2, 2, {"CCC"}, false})
+
+    eval('rpcnotify('..channel..', "Goodbye")')
+    expectn('Goodbye', {})
+  end)
+
+  it('works with :sort', function()
+    -- test for :sort
+    local b, tick = editoriginal(true, {"B", "D", "C", "A", "E"})
+    command('%sort')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 5, {"A", "B", "C", "D", "E"}, false})
+  end)
+
+  it('works with :left', function()
+    local b, tick = editoriginal(true, {" A", "  B", "B", "\tB", "\t\tC"})
+    command('2,4left')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 4, {"B", "B", "B"}, false})
+  end)
+
+  it('works with :right', function()
+    local b, tick = editoriginal(true, {" A",
+                                        "\t  B",
+                                        "\t  \tBB",
+                                        " \tB",
+                                        "\t\tC"})
+    command('set ts=2 et')
+    command('2,4retab')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 4, {"    B", "      BB", "  B"}, false})
+  end)
+
+  it('works with :move', function()
+    local b, tick = editoriginal(true, origlines)
+    -- move text down towards the end of the file
+    command('2,3move 4')
+    tick = tick + 2
+    expectn('nvim_buf_lines_event', {b, tick, 4, 4, {"original line 2",
+                                           "original line 3"}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 3, {}, false})
+
+    -- move text up towards the start of the file
+    tick = reopen(b, origlines)
+    command('4,5move 2')
+    tick = tick + 2
+    expectn('nvim_buf_lines_event', {b, tick, 2, 2, {"original line 4",
+                                           "original line 5"}, false})
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 5, 7, {}, false})
+  end)
+
+  it('when you manually add/remove folds', function()
+    local b = editoriginal(true)
+    local tick = reopenwithfolds(b)
+
+    -- delete the inner fold
+    command('normal! zR3Gzd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 1, 4, {'original line 2',
+                                           'original line 3',
+                                           'original line 4'}, false})
+    -- delete the outer fold
+    command('normal! zd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 6, origlines, false})
+
+    -- discard changes and put the folds back
+    tick = reopenwithfolds(b)
+
+    -- remove both folds at once
+    command('normal! ggzczD')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 6, origlines, false})
+
+    -- discard changes and put the folds back
+    tick = reopenwithfolds(b)
+
+    -- now delete all folds at once
+    command('normal! zE')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 6, origlines, false})
+
+    -- create a fold from line 4 to the end of the file
+    command('normal! 4GA/*{{{*/')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 4, {'original line 4/*{{{*/'}, false})
+
+    -- delete the fold which only has one marker
+    command('normal! Gzd')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 3, 6, {'original line 4',
+                                           'original line 5',
+                                           'original line 6'}, false})
+  end)
+
+  it('detaches if the buffer is closed', function()
+    local b, tick = editoriginal(true, {'AAA'})
+    local channel = nvim('get_api_info')[1]
+
+    -- Test that buffer events are working.
+    command('normal! x')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'AA'}, false})
+    command('undo')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'AAA'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_changedtick_event', {b, tick})
+
+    -- close our buffer by creating a new one
+    command('enew')
+    expectn('nvim_buf_detach_event', {b})
+
+    -- Reopen the original buffer, make sure there are no buffer events sent.
+    command('b1')
+    command('normal! x')
+
+    eval('rpcnotify('..channel..', "Hello There")')
+    expectn('Hello There', {})
+  end)
+
+  it('stays attached if the buffer is hidden', function()
+    local b, tick = editoriginal(true, {'AAA'})
+    local channel = nvim('get_api_info')[1]
+
+    -- Test that buffer events are working.
+    command('normal! x')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'AA'}, false})
+    command('undo')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'AAA'}, false})
+    tick = tick + 1
+    expectn('nvim_buf_changedtick_event', {b, tick})
+
+    -- Close our buffer by creating a new one.
+    command('set hidden')
+    command('enew')
+
+    -- Assert that no nvim_buf_detach_event is sent.
+    eval('rpcnotify('..channel..', "Hello There")')
+    expectn('Hello There', {})
+
+    -- Reopen the original buffer, assert that buffer events are still active.
+    command('b1')
+    command('normal! x')
+    tick = tick + 1
+    expectn('nvim_buf_lines_event', {b, tick, 0, 1, {'AA'}, false})
+  end)
+
+  it('detaches if the buffer is unloaded/deleted/wiped',
+     function()
+    -- start with a blank nvim
+    helpers.clear()
+    -- need to make a new window with a buffer because :bunload doesn't let you
+    -- unload the last buffer
+    for _, cmd in ipairs({'bunload', 'bdelete', 'bwipeout'}) do
+      command('new')
+      -- open a brand spanking new file
+      local b = open(true, {'AAA'})
+
+      -- call :bunload or whatever the command is, and then check that we
+      -- receive a nvim_buf_detach_event
+      command(cmd)
+      expectn('nvim_buf_detach_event', {b})
+    end
+  end)
+
+  it('does not send the buffer content if not requested', function()
+    helpers.clear()
+    local b, tick = editoriginal(false)
+    ok(buffer('attach', b, false, {}))
+    expectn('nvim_buf_changedtick_event', {b, tick})
+  end)
+
+  it('returns a proper error on nonempty options dict', function()
+    helpers.clear()
+    local b = editoriginal(false)
+    expect_err("dict isn't empty", buffer, 'attach', b, false, {builtin="asfd"})
+  end)
+
+end)