fix(calendar): fix bug with empty date (#744)

- simplify state by replacing month with date
- handle rendering correctly when changing month

Co-authored-by: Sebastian Flügge <[email protected]>

lua/orgmode/objects/calendar.lua

@@ -17,7 +17,6 @@ local small_minute_step = config.calendar.min_small_step or config.org_time_stam
 ---@field callback fun(date: OrgDate | nil, cleared?: boolean)
 ---@field namespace function
 ---@field date OrgDate?
----@field month OrgDate
 ---@field title? string
 ---@field on_day? OrgCalendarOnRenderDay
 ---@field selected OrgDate?
@@ -26,8 +25,7 @@ local small_minute_step = config.calendar.min_small_step or config.org_time_stam
 local Calendar = {
   win = nil,
   buf = nil,
-  date = nil,
-  month = Date.today():start_of('month'),
+  date = Date.today():start_of('month'),
   selected = nil,
   select_state = SelState.DAY,
   clearable = false,
@@ -46,9 +44,8 @@ function Calendar.new(data)
   this.on_day = data.on_day
   if data.date then
     this.date = data.date
-    this.month = this.date:set({ day = 1 })
   else
-    this.month = Date.today():start_of('month')
+    this.date = Date.today()
   end
   return this
 end
@@ -157,24 +154,28 @@ function Calendar:render()
   end
 
   -- construct title (Month YYYY)
-  local title = self.month:format('%B %Y')
+  local title = self.date:format('%B %Y')
   title = string.rep(' ', math.floor((width - title:len()) / 2)) .. title
 
   -- insert whitespace before first day of month
-  local start_weekday = self.month:get_isoweekday()
+  local first_of_month = self.date:start_of('month')
+
+  local end_of_month = self.date:end_of('month')
+  local start_weekday = first_of_month:get_isoweekday()
   if start_from_sunday then
-    start_weekday = self.month:get_weekday()
+    start_weekday = first_of_month:get_weekday()
   end
+
   while start_weekday > 1 do
     table.insert(cal_rows[1], '  ')
     start_weekday = start_weekday - 1
   end
 
   -- insert dates into cal_rows
-  local dates = self.month:get_range_until(self.month:end_of('month'))
+  local dates = first_of_month:get_range_until(end_of_month)
   local current_row = 1
-  for _, date in ipairs(dates) do
-    table.insert(cal_rows[current_row], date:format('%d'))
+  for _, day in ipairs(dates) do
+    table.insert(cal_rows[current_row], day:format('%d'))
     if #cal_rows[current_row] % 7 == 0 then
       current_row = current_row + 1
     end
@@ -236,8 +237,8 @@ function Calendar:render()
         break
       end
       if from and to then
-        local date = self.month:set({ day = num })
-        self:on_render_day(date, {
+        local day = self.date:set({ day = num })
+        self:on_render_day(day, {
           from = from,
           to = to,
           line = i,
@@ -322,7 +323,7 @@ end
 
 function Calendar:forward()
   self:_ensure_day()
-  self.month = self.month:add({ month = vim.v.count1 })
+  self.date = self.date:start_of('month'):add({ month = vim.v.count1 })
   self:render()
   vim.fn.cursor(2, 1)
   vim.fn.search('01')
@@ -331,9 +332,9 @@ end
 
 function Calendar:backward()
   self:_ensure_day()
-  self.month = self.month:subtract({ month = vim.v.count1 })
+  self.date = self.date:start_of('month'):subtract({ month = vim.v.count1 }):end_of('month')
   self:render()
-  vim.fn.cursor(vim.fn.line('$'), 0)
+  vim.fn.cursor(8, 0)
   vim.fn.search([[\d\d]], 'b')
   self:render()
 end
@@ -499,13 +500,13 @@ end
 
 function Calendar:reset()
   self:_ensure_day()
-  local today = self.month:set_todays_date()
-  self.month = today:set({ day = 1 })
+  self.date = self.date:set_todays_date()
   self:render()
   vim.fn.cursor(2, 1)
-  vim.fn.search(today:format('%d'), 'W')
+  vim.fn.search(self.date:format('%d'), 'W')
 end
 
+---@return OrgDate?
 function Calendar:get_selected_date()
   if self.select_state ~= SelState.DAY then
     return self.date
@@ -519,7 +520,6 @@ function Calendar:get_selected_date()
     return utils.echo_warning('Please select valid day number.', nil, false)
   end
   return self.date:set({
-    month = self.month.month,
     day = day,
     date_only = self.date.date_only,
   })
@@ -549,7 +549,7 @@ end
 function Calendar:dispose()
   self.win = nil
   self.buf = nil
-  self.month = Date.today():start_of('month')
+  self.date = Date.today():start_of('month')
   if self.callback then
     self.callback(nil)
     self.callback = nil
@@ -566,7 +566,7 @@ end
 
 function Calendar:read_date()
   self:_ensure_day()
-  local current_date = self:get_selected_date()
+  local current_date = self:get_selected_date() or Date.today()
   vim.ui.input({ prompt = 'Enter date: ', default = current_date:to_string() }, function(result)
     if result then
       local date = Date.from_string(result)
@@ -575,7 +575,6 @@ function Calendar:read_date()
       end
 
       self.date = date
-      self.month = date:set({ day = 1 })
       self:render()
       vim.fn.cursor(2, 1)
       vim.fn.search(date:format('%d'), 'W')

lua/orgmode/objects/date.lua

@@ -703,6 +703,7 @@ function Date:is_in_date_range(date)
   return false
 end
 
+---Range of dates, excluding date
 ---@param date OrgDate
 ---@return OrgDate[]
 function Date:get_range_until(date)

lua/orgmode/utils/init.lua

@@ -108,6 +108,7 @@ end
 ---@param msg string|table
 ---@param additional_msg? table
 ---@param store_in_history? boolean
+---@return nil
 function utils.echo_warning(msg, additional_msg, store_in_history)
   return utils._echo(msg, 'WarningMsg', additional_msg, store_in_history)
 end
@@ -127,6 +128,7 @@ function utils.echo_info(msg, additional_msg, store_in_history)
 end
 
 ---@private
+---@return nil
 function utils._echo(msg, hl, additional_msg, store_in_history)
   vim.cmd([[redraw!]])
   if type(msg) == 'table' then

tests/plenary/object/calendar_spec.lua

@@ -0,0 +1,83 @@
+local helpers = require('tests.plenary.helpers')
+local Calendar = require('orgmode.objects.calendar')
+local Date = require('orgmode.objects.date')
+
+local close_all_buffers = function()
+  vim.cmd([[silent! %bw!]])
+end
+
+local feed = function(keys)
+  vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes(keys, true, true, true), 'x', true)
+end
+
+describe('Calendar', function()
+  after_each(close_all_buffers)
+  it('should open a calendar at plain headline', function()
+    helpers.create_agenda_file({
+      '#+TITLE: Test',
+      '',
+      '* Some Headline',
+    })
+    vim.fn.cursor(3, 1)
+    vim.cmd('norm ,oid')
+  end)
+
+  it('should change a deadline', function()
+    helpers.create_agenda_file({
+      '#+TITLE: Test',
+      '',
+      '* Some Headline',
+      '  DEADLINE: <2024-06-01 Sat>',
+    })
+    vim.fn.cursor(3, 1)
+    vim.cmd('norm ,oid')
+    feed('l<CR>')
+
+    assert.are.same({
+      '* Some Headline',
+      '  DEADLINE: <2024-06-02 Sun>',
+    }, vim.api.nvim_buf_get_lines(0, 2, 4, false))
+  end)
+
+  it('should render the month correctly', function()
+    helpers.create_agenda_file({
+      '#+TITLE: Test',
+      '',
+      '* Some Headline',
+      '  DEADLINE: <2024-05-31 Fri>',
+    })
+    vim.fn.cursor(3, 1)
+    vim.cmd('norm ,oid')
+
+    assert.are.same({
+      ' Mon  Tue  Wed  Thu  Fri  Sat  Sun',
+      '           01   02   03   04   05 ',
+      ' 06   07   08   09   10   11   12 ',
+      ' 13   14   15   16   17   18   19 ',
+      ' 20   21   22   23   24   25   26 ',
+      ' 27   28   29   30   31 ',
+      '  ',
+      '               --:--              ',
+      '',
+    }, vim.api.nvim_buf_get_lines(0, 1, 10, false))
+  end)
+
+  it('should render at the end of a long month', function()
+    local date = Date.from_string('2024-05-31')
+    local cal_instance = Calendar.new({ date = date, title = date:to_string() })
+    cal_instance:open()
+    local cal_date = cal_instance.date
+    assert.are.same('2024-05-31 Fri', cal_date and cal_date:to_string())
+  end)
+
+  it('should handle the end of the month correctly', function()
+    local date = Date.from_string('2024-05-31')
+    local cal_instance = Calendar.new({ date = date, title = date:to_string() })
+    cal_instance:open()
+    feed('l')
+    vim.wait(50)
+    feed('<CR>')
+    local cal_date = cal_instance.date
+    assert.are.same('2024-06-01 Sat', cal_date and cal_date:to_string())
+  end)
+end)

tests/plenary/object/date_spec.lua

@@ -337,6 +337,16 @@ describe('Date object', function()
     assert.are.same('2024-01-03 Wed 14:00', date:to_string())
   end)
 
+  it('should be robust for some arithmetic', function()
+    local date = Date.from_string('2024-06-04')
+    date = date:start_of('month')
+    assert.are.same('2024-06-01 Sat', date:to_string())
+    date = date:subtract({ month = 1 })
+    assert.are.same('2024-05-01 Wed', date:to_string())
+    date = date:end_of('month')
+    assert.are.same('2024-05-31 Fri', date:to_string())
+  end)
+
   it('should compare dates', function()
     local date = Date.from_string('2021-05-12 14:00')
     local date_end = Date.from_string('2021-05-12 23:30')