test/unit: some unit tests for undo.c #4985

test/unit/undo_spec.lua

@@ -0,0 +1,213 @@
+local lfs = require('lfs')
+local helpers = require('test.unit.helpers')
+
+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 = options.p_udir  -- save the old value of p_udir (undodir)
+
+-- Values expected by tests. Set in the setup function and destroyed in teardown
+local file_buffer = nil
+local buffer_hash = nil
+
+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)
+
+  before_each(function()
+    -- create a new buffer
+    local c_file = to_cstr('../test/unit/undo_spec.lua')
+    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)
+
+  -- 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
+
+  it('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)
+  
+  it('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)
+  
+  it('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)
+
+  it('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)
+
+  it('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)
+
+  it('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))
+    local text_file, err = io.open(correct_name, "w")
+    if err then
+      pending()
+    end
+    text_file:write(file_contents)
+    text_file:close()
+
+    u_write_undo(nil, true, file_buffer, buffer_hash)  -- Call with forceit flag enabled
+
+    local undo_file, undo_file_err = io.open(correct_name, "r")
+    if undo_file_err then
+      pending()
+    end
+    local undo_file_contents = undo_file:read("*a")  -- Read all
+
+    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)
+
+  it('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
+
+    os.execute('sleep 1s')  -- Ensure there will be some 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)
+  
+  it('does not overwrite an existing file that is not an undo file', function()
+    -- TODO: write test
+  end)
+  
+  it('does not overwrite an existing file that has the wrong permissions', function()
+    -- TODO: write test
+  end)
+  
+  it('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)