Merge #4985

closes #4985

3 files changed, 289 insertions, 64 deletions

diff --git a/test/functional/helpers.lua b/test/functional/helpers.lua
index 655200e6f7..9895281773 100644
--- a/test/functional/helpers.lua
+++ b/test/functional/helpers.lua
@@ -12,15 +12,18 @@ local Paths = require('test.config.paths')
 
 local check_cores = global_helpers.check_cores
 local check_logs = global_helpers.check_logs
-local neq = global_helpers.neq
+local dedent = global_helpers.dedent
 local eq = global_helpers.eq
 local expect_err = global_helpers.expect_err
-local ok = global_helpers.ok
+local filter = global_helpers.filter
 local map = global_helpers.map
 local matches = global_helpers.matches
-local filter = global_helpers.filter
-local dedent = global_helpers.dedent
+local neq = global_helpers.neq
+local ok = global_helpers.ok
+local read_file = global_helpers.read_file
+local sleep = global_helpers.sleep
 local table_flatten = global_helpers.table_flatten
+local write_file = global_helpers.write_file
 
 local start_dir = lfs.currentdir()
 -- XXX: NVIM_PROG takes precedence, QuickBuild sets it.
@@ -374,34 +377,6 @@ local function feed_command(...)
   end
 end
 
--- Dedent the given text and write it to the file name.
-local function write_file(name, text, no_dedent, append)
-  local file = io.open(name, (append and 'a' or 'w'))
-  if type(text) == 'table' then
-    -- Byte blob
-    local bytes = text
-    text = ''
-    for _, char in ipairs(bytes) do
-      text = ('%s%c'):format(text, char)
-    end
-  elseif not no_dedent then
-    text = dedent(text)
-  end
-  file:write(text)
-  file:flush()
-  file:close()
-end
-
-local function read_file(name)
-  local file = io.open(name, 'r')
-  if not file then
-    return nil
-  end
-  local ret = file:read('*a')
-  file:close()
-  return ret
-end
-
 local sourced_fnames = {}
 local function source(code)
   local fname = tmpname()
@@ -466,11 +441,6 @@ local function wait()
   session:request('nvim_eval', '1')
 end
 
--- sleeps the test runner (_not_ the nvim instance)
-local function sleep(ms)
-  luv.sleep(ms)
-end
-
 local function curbuf_contents()
   wait()  -- Before inspecting the buffer, process all input.
   return table.concat(curbuf('get_lines', 0, -1, true), '\n')
@@ -682,31 +652,6 @@ local function alter_slashes(obj)
   end
 end
 
-local function hexdump(str)
-  local len = string.len(str)
-  local dump = ""
-  local hex = ""
-  local asc = ""
-
-  for i = 1, len do
-    if 1 == i % 8 then
-      dump = dump .. hex .. asc .. "\n"
-      hex = string.format("%04x: ", i - 1)
-      asc = ""
-    end
-
-    local ord = string.byte(str, i)
-    hex = hex .. string.format("%02x ", ord)
-    if ord >= 32 and ord <= 126 then
-      asc = asc .. string.char(ord)
-    else
-      asc = asc .. "."
-    end
-  end
-
-  return dump .. hex .. string.rep("   ", 8 - len % 8) .. asc
-end
-
 local module = {
   NIL = mpack.NIL,
   alter_slashes = alter_slashes,
@@ -737,7 +682,6 @@ local module = {
   filter = filter,
   funcs = funcs,
   get_pathsep = get_pathsep,
-  hexdump = hexdump,
   insert = insert,
   iswin = iswin,
   map = map,
diff --git a/test/helpers.lua b/test/helpers.lua
index efc0e911f1..0d3fe1316b 100644
--- a/test/helpers.lua
+++ b/test/helpers.lua
@@ -1,4 +1,5 @@
 local assert = require('luassert')
+local luv = require('luv')
 local lfs = require('lfs')
 
 local quote_me = '[^.%w%+%-%@%_%/]' -- complement (needn't quote)
@@ -33,6 +34,11 @@ local function popen_w(...)
   return io.popen(argss_to_cmd(...), 'w')
 end
 
+-- sleeps the test runner (_not_ the nvim instance)
+local function sleep(ms)
+  luv.sleep(ms)
+end
+
 local check_logs_useless_lines = {
   ['Warning: noted but unhandled ioctl']=1,
   ['could cause spurious value errors to appear']=2,
@@ -612,7 +618,60 @@ local function table_flatten(arr)
   return result
 end
 
-return {
+local function hexdump(str)
+  local len = string.len(str)
+  local dump = ""
+  local hex = ""
+  local asc = ""
+
+  for i = 1, len do
+    if 1 == i % 8 then
+      dump = dump .. hex .. asc .. "\n"
+      hex = string.format("%04x: ", i - 1)
+      asc = ""
+    end
+
+    local ord = string.byte(str, i)
+    hex = hex .. string.format("%02x ", ord)
+    if ord >= 32 and ord <= 126 then
+      asc = asc .. string.char(ord)
+    else
+      asc = asc .. "."
+    end
+  end
+
+  return dump .. hex .. string.rep("   ", 8 - len % 8) .. asc
+end
+
+local function read_file(name)
+  local file = io.open(name, 'r')
+  if not file then
+    return nil
+  end
+  local ret = file:read('*a')
+  file:close()
+  return ret
+end
+
+-- Dedent the given text and write it to the file name.
+local function write_file(name, text, no_dedent, append)
+  local file = io.open(name, (append and 'a' or 'w'))
+  if type(text) == 'table' then
+    -- Byte blob
+    local bytes = text
+    text = ''
+    for _, char in ipairs(bytes) do
+      text = ('%s%c'):format(text, char)
+    end
+  elseif not no_dedent then
+    text = dedent(text)
+  end
+  file:write(text)
+  file:flush()
+  file:close()
+end
+
+local module = {
   REMOVE_THIS = REMOVE_THIS,
   argss_to_cmd = argss_to_cmd,
   check_cores = check_cores,
@@ -630,6 +689,7 @@ return {
   format_string = format_string,
   glob = glob,
   hasenv = hasenv,
+  hexdump = hexdump,
   intchar2lua = intchar2lua,
   map = map,
   matches = matches,
@@ -638,11 +698,16 @@ return {
   ok = ok,
   popen_r = popen_r,
   popen_w = popen_w,
+  read_file = read_file,
   repeated_read_cmd = repeated_read_cmd,
+  sleep = sleep,
   shallowcopy = shallowcopy,
   table_flatten = table_flatten,
   tmpname = tmpname,
   uname = uname,
   updated = updated,
   which = which,
+  write_file = write_file,
 }
+
+return module
diff --git a/test/unit/undo_spec.lua b/test/unit/undo_spec.lua
new file mode 100644
index 0000000000..ab172e89f2
--- /dev/null
+++ b/test/unit/undo_spec.lua
@@ -0,0 +1,216 @@
+local helpers = require('test.unit.helpers')(after_each)
+local itp = helpers.gen_itp(it)
+local lfs = require('lfs')
+local child_call_once = helpers.child_call_once
+
+local global_helpers = require('test.helpers')
+local hexdump = global_helpers.hexdump
+local sleep = global_helpers.sleep
+
+local ffi = helpers.ffi
+local cimport = helpers.cimport
+local to_cstr = helpers.to_cstr
+local neq = helpers.neq
+local eq = helpers.eq
+
+cimport('./src/nvim/ex_cmds_defs.h')
+cimport('./src/nvim/buffer_defs.h')
+local options = cimport('./src/nvim/option_defs.h')
+-- TODO: remove: local vim = cimport('./src/nvim/vim.h')
+local undo = cimport('./src/nvim/undo.h')
+local buffer = cimport('./src/nvim/buffer.h')
+
+local old_p_udir = nil
+
+-- Values expected by tests. Set in the setup function and destroyed in teardown
+local file_buffer = nil
+local buffer_hash = nil
+
+child_call_once(function()
+  if old_p_udir == nil then
+    old_p_udir = options.p_udir  -- save the old value of p_udir (undodir)
+  end
+
+  -- create a new buffer
+  local c_file = to_cstr('Xtest-unit-undo')
+  file_buffer = buffer.buflist_new(c_file, c_file, 1, buffer.BLN_LISTED)
+  file_buffer.b_u_numhead = 1 -- Pretend that the buffer has been changed
+
+  -- TODO(christopher.waldon.dev@gmail.com): replace the 32 with UNDO_HASH_SIZE
+  -- requires refactor of UNDO_HASH_SIZE into constant/enum for ffi
+  --
+  -- compute a hash for this undofile
+  buffer_hash = ffi.new('char_u[32]')
+  undo.u_compute_hash(buffer_hash)
+end)
+
+
+describe('u_write_undo', function()
+  setup(function()
+    lfs.mkdir('unit-test-directory')
+    lfs.chdir('unit-test-directory')
+    options.p_udir = to_cstr(lfs.currentdir())  -- set p_udir to be the test dir
+  end)
+
+  teardown(function()
+    lfs.chdir('..')
+    local success, err = lfs.rmdir('unit-test-directory')
+    if not success then
+      print(err)  -- inform tester if directory fails to delete
+    end
+    options.p_udir = old_p_udir  --restore old p_udir
+  end)
+
+  -- Lua wrapper for u_write_undo
+  local function u_write_undo(name, forceit, buf, buf_hash)
+    if name ~= nil then
+      name = to_cstr(name)
+    end
+
+    return undo.u_write_undo(name, forceit, buf, buf_hash)
+  end
+
+  itp('writes an undo file to undodir given a buffer and hash', function()
+    u_write_undo(nil, false, file_buffer, buffer_hash)
+    local correct_name = ffi.string(undo.u_get_undo_file_name(file_buffer.b_ffname, false))
+    local undo_file = io.open(correct_name, "r")
+
+    neq(undo_file, nil)
+    local success, err = os.remove(correct_name)  -- delete the file now that we're done with it.
+    if not success then
+      print(err)  -- inform tester if undofile fails to delete
+    end
+  end)
+
+  itp('writes a correctly-named undo file to undodir given a name, buffer, and hash', function()
+    local correct_name = "undofile.test"
+    u_write_undo(correct_name, false, file_buffer, buffer_hash)
+    local undo_file = io.open(correct_name, "r")
+
+    neq(undo_file, nil)
+    local success, err = os.remove(correct_name)  -- delete the file now that we're done with it.
+    if not success then
+      print(err)  -- inform tester if undofile fails to delete
+    end
+  end)
+
+  itp('does not write an undofile when the buffer has no valid undofile name', function()
+    -- TODO(christopher.waldon.dev@gmail.com): Figure out how to test this.
+    -- it's hard because u_get_undo_file_name() would need to return null
+  end)
+
+  itp('writes the undofile with the same permissions as the original file', function()
+    -- Create Test file and set permissions
+    local test_file_name = "./test.file"
+    local test_permission_file = io.open(test_file_name, "w")
+    test_permission_file:write("testing permissions")
+    test_permission_file:close()
+    local test_permissions = lfs.attributes(test_file_name).permissions
+
+    -- Create vim buffer
+    local c_file = to_cstr(test_file_name)
+    file_buffer = buffer.buflist_new(c_file, c_file, 1, buffer.BLN_LISTED)
+    file_buffer.b_u_numhead = 1 -- Pretend that the buffer has been changed
+
+    u_write_undo(nil, false, file_buffer, buffer_hash)
+
+    -- Find out the correct name of the undofile
+    local undo_file_name = ffi.string(undo.u_get_undo_file_name(file_buffer.b_ffname, false))
+
+    -- Find out the permissions of the new file
+    local permissions = lfs.attributes(undo_file_name).permissions
+    eq(test_permissions, permissions)
+
+    -- delete the file now that we're done with it.
+    local success, err = os.remove(test_file_name)
+    if not success then
+      print(err)  -- inform tester if undofile fails to delete
+    end
+    success, err = os.remove(undo_file_name)
+    if not success then
+      print(err)  -- inform tester if undofile fails to delete
+    end
+  end)
+
+  itp('writes an undofile only readable by the user if the buffer is unnamed', function()
+    local correct_permissions = "rw-------"
+    local undo_file_name = "test.undo"
+
+    -- Create vim buffer
+    file_buffer = buffer.buflist_new(nil, nil, 1, buffer.BLN_LISTED)
+    file_buffer.b_u_numhead = 1 -- Pretend that the buffer has been changed
+
+    u_write_undo(undo_file_name, false, file_buffer, buffer_hash)
+
+    -- Find out the permissions of the new file
+    local permissions = lfs.attributes(undo_file_name).permissions
+    eq(correct_permissions, permissions)
+
+    -- delete the file now that we're done with it.
+    local success, err = os.remove(undo_file_name)
+    if not success then
+      print(err)  -- inform tester if undofile fails to delete
+    end
+  end)
+
+  itp('forces writing undo file for :wundo! command', function()
+    local file_contents = "testing permissions"
+    -- Write a text file where the undofile should go
+    local correct_name = ffi.string(undo.u_get_undo_file_name(file_buffer.b_ffname, false))
+    global_helpers.write_file(correct_name, file_contents, true, false)
+
+    -- Call with `forceit`.
+    u_write_undo(correct_name, true, file_buffer, buffer_hash)
+
+    local undo_file_contents = global_helpers.read_file(correct_name)
+
+    neq(file_contents, undo_file_contents)
+    local success, deletion_err = os.remove(correct_name)  -- delete the file now that we're done with it.
+    if not success then
+      print(deletion_err)  -- inform tester if undofile fails to delete
+    end
+  end)
+
+  itp('overwrites an existing undo file', function()
+    u_write_undo(nil, false, file_buffer, buffer_hash)
+    local correct_name = ffi.string(undo.u_get_undo_file_name(file_buffer.b_ffname, false))
+
+    local file_last_modified = lfs.attributes(correct_name).modification
+
+    sleep(1000)  -- Ensure difference in timestamps.
+    file_buffer.b_u_numhead = 1  -- Mark it as if there are changes
+    u_write_undo(nil, false, file_buffer, buffer_hash)
+
+    local file_last_modified_2 = lfs.attributes(correct_name).modification
+
+    -- print(file_last_modified, file_last_modified_2)
+    neq(file_last_modified, file_last_modified_2)
+    local success, err = os.remove(correct_name)  -- delete the file now that we're done with it.
+    if not success then
+      print(err)  -- inform tester if undofile fails to delete
+    end
+  end)
+
+  itp('does not overwrite an existing file that is not an undo file', function()
+    -- TODO: write test
+  end)
+
+  itp('does not overwrite an existing file that has the wrong permissions', function()
+    -- TODO: write test
+  end)
+
+  itp('does not write an undo file if there is no undo information for the buffer', function()
+    file_buffer.b_u_numhead = 0  -- Mark it as if there is no undo information
+    local correct_name = ffi.string(undo.u_get_undo_file_name(file_buffer.b_ffname, false))
+
+    local existing_file = io.open(correct_name,"r")
+    if existing_file then
+      existing_file:close()
+      os.remove(correct_name)
+    end
+    u_write_undo(nil, false, file_buffer, buffer_hash)
+    local undo_file = io.open(correct_name, "r")
+
+    eq(undo_file, nil)
+  end)
+end)