1 files changed, 142 insertions, 0 deletions
diff --git a/test/functional/vimscript/changedtick_spec.lua b/test/functional/vimscript/changedtick_spec.lua
new file mode 100644
index 0000000000..99406d9d7a
--- /dev/null
+++ b/test/functional/vimscript/changedtick_spec.lua
@@ -0,0 +1,142 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local eq = helpers.eq
+local eval = helpers.eval
+local feed = helpers.feed
+local clear = helpers.clear
+local funcs = helpers.funcs
+local meths = helpers.meths
+local command = helpers.command
+local exc_exec = helpers.exc_exec
+local redir_exec = helpers.redir_exec
+local pcall_err = helpers.pcall_err
+local curbufmeths = helpers.curbufmeths
+
+before_each(clear)
+
+local function changedtick()
+  local ct = curbufmeths.get_changedtick()
+  eq(ct, curbufmeths.get_var('changedtick'))
+  eq(ct, curbufmeths.get_var('changedtick'))
+  eq(ct, eval('b:changedtick'))
+  eq(ct, eval('b:["changedtick"]'))
+  eq(ct, eval('b:.changedtick'))
+  eq(ct, funcs.getbufvar('%', 'changedtick'))
+  eq(ct, funcs.getbufvar('%', '').changedtick)
+  eq(ct, eval('b:').changedtick)
+  return ct
+end
+
+describe('b:changedtick', function()
+  -- Ported tests from Vim-8.0.333
+  it('increments', function()  -- Test_changedtick_increments
+    -- New buffer has an empty line, tick starts at 2
+    eq(2, changedtick())
+    funcs.setline(1, 'hello')
+    eq(3, changedtick())
+    eq(0, exc_exec('undo'))
+    -- Somehow undo counts as two changes
+    eq(5, changedtick())
+  end)
+  it('is present in b: dictionary', function()
+    eq(2, changedtick())
+    command('let d = b:')
+    eq(2, meths.get_var('d').changedtick)
+  end)
+  it('increments at bdel', function()
+    command('new')
+    eq(2, changedtick())
+    local bnr = curbufmeths.get_number()
+    eq(2, bnr)
+    command('bdel')
+    eq(3, funcs.getbufvar(bnr, 'changedtick'))
+    eq(1, curbufmeths.get_number())
+  end)
+  it('fails to be changed by user', function()
+    local ct = changedtick()
+    local ctn = ct + 100500
+    eq(0, exc_exec('let d = b:'))
+    eq('\nE46: Cannot change read-only variable "b:changedtick"',
+       redir_exec('let b:changedtick = ' .. ctn))
+    eq('\nE46: Cannot change read-only variable "b:["changedtick"]"',
+       redir_exec('let b:["changedtick"] = ' .. ctn))
+    eq('\nE46: Cannot change read-only variable "b:.changedtick"',
+       redir_exec('let b:.changedtick = ' .. ctn))
+    eq('\nE46: Cannot change read-only variable "d.changedtick"',
+       redir_exec('let d.changedtick = ' .. ctn))
+    eq('Key is read-only: changedtick',
+      pcall_err(curbufmeths.set_var, 'changedtick', ctn))
+
+    eq('\nE795: Cannot delete variable b:changedtick',
+       redir_exec('unlet b:changedtick'))
+    eq('\nE46: Cannot change read-only variable "b:.changedtick"',
+       redir_exec('unlet b:.changedtick'))
+    eq('\nE46: Cannot change read-only variable "b:["changedtick"]"',
+       redir_exec('unlet b:["changedtick"]'))
+    eq('\nE46: Cannot change read-only variable "d.changedtick"',
+       redir_exec('unlet d.changedtick'))
+    eq('Key is read-only: changedtick',
+      pcall_err(curbufmeths.del_var, 'changedtick'))
+    eq(ct, changedtick())
+
+    eq('\nE46: Cannot change read-only variable "b:["changedtick"]"',
+       redir_exec('let b:["changedtick"] += ' .. ctn))
+    eq('\nE46: Cannot change read-only variable "b:["changedtick"]"',
+       redir_exec('let b:["changedtick"] -= ' .. ctn))
+    eq('\nE46: Cannot change read-only variable "b:["changedtick"]"',
+       redir_exec('let b:["changedtick"] .= ' .. ctn))
+
+    eq(ct, changedtick())
+
+    funcs.setline(1, 'hello')
+
+    eq(ct + 1, changedtick())
+  end)
+  it('is listed in :let output', function()
+    eq('\nb:changedtick         #2',
+       redir_exec(':let b:'))
+  end)
+  it('fails to unlock b:changedtick', function()
+    eq(0, exc_exec('let d = b:'))
+    eq(0, funcs.islocked('b:changedtick'))
+    eq(0, funcs.islocked('d.changedtick'))
+    eq('\nE940: Cannot lock or unlock variable b:changedtick',
+       redir_exec('unlockvar b:changedtick'))
+    eq('\nE46: Cannot change read-only variable "d.changedtick"',
+       redir_exec('unlockvar d.changedtick'))
+    eq(0, funcs.islocked('b:changedtick'))
+    eq(0, funcs.islocked('d.changedtick'))
+    eq('\nE940: Cannot lock or unlock variable b:changedtick',
+       redir_exec('lockvar b:changedtick'))
+    eq('\nE46: Cannot change read-only variable "d.changedtick"',
+       redir_exec('lockvar d.changedtick'))
+    eq(0, funcs.islocked('b:changedtick'))
+    eq(0, funcs.islocked('d.changedtick'))
+  end)
+  it('is being completed', function()
+    feed(':echo b:<Tab><Home>let cmdline="<End>"<CR>')
+    eq('echo b:changedtick', meths.get_var('cmdline'))
+  end)
+  it('cannot be changed by filter() or map()', function()
+    eq(2, changedtick())
+    eq('\nE795: Cannot delete variable filter() argument',
+       redir_exec('call filter(b:, 0)'))
+    eq('\nE742: Cannot change value of map() argument',
+       redir_exec('call map(b:, 0)'))
+    eq('\nE742: Cannot change value of map() argument',
+       redir_exec('call map(b:, "v:val")'))
+    eq(2, changedtick())
+  end)
+  it('cannot be remove()d', function()
+    eq(2, changedtick())
+    eq('\nE795: Cannot delete variable remove() argument',
+       redir_exec('call remove(b:, "changedtick")'))
+    eq(2, changedtick())
+  end)
+  it('does not inherit VAR_FIXED when copying dictionary over', function()
+    eq(2, changedtick())
+    eq('', redir_exec('let d1 = copy(b:)|let d1.changedtick = 42'))
+    eq('', redir_exec('let d2 = copy(b:)|unlet d2.changedtick'))
+    eq(2, changedtick())
+  end)
+end)