zh: add special plurlized words

arrow/locales.py

@@ -976,6 +976,15 @@ class ChineseCNLocale(Locale):
         "years": "{0}年",
     }
 
+    special_dayframes = {
+        -2: "前天",
+        -1: "昨天",
+        1: "明天",
+        2: "后天",
+    }
+
+    special_yearframes = {-2: "前年", -1: "去年", 1: "明年", 2: "后年"}
+
     month_names = [
         "",
         "一月",
@@ -1010,6 +1019,20 @@ class ChineseCNLocale(Locale):
     day_names = ["", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六", "星期日"]
     day_abbreviations = ["", "一", "二", "三", "四", "五", "六", "日"]
 
+    def _format_relative(
+        self, humanized: str, timeframe: TimeFrameLiteral, delta: Union[float, int]
+    ) -> str:
+        if timeframe in ("day", "days"):
+            special = self.special_dayframes.get(int(delta))
+            if special:
+                return special
+        elif timeframe in ("year", "years"):
+            special = self.special_yearframes.get(int(delta))
+            if special:
+                return special
+
+        return super()._format_relative(humanized, timeframe, delta)
+
 
 class ChineseTWLocale(Locale):
 

tests/test_locales.py

@@ -2058,6 +2058,43 @@ def test_format_timeframe(self):
         assert self.locale._format_timeframe("year", 1) == "1年"
         assert self.locale._format_timeframe("years", 12) == "12年"
 
+    def test_format_relative(self):
+        assert self.locale._format_relative("刚才", "now", 0) == "刚才"
+
+        assert self.locale._format_relative("1秒", "second", 1) == "1秒后"
+        assert self.locale._format_relative("2秒", "seconds", 2) == "2秒后"
+        assert self.locale._format_relative("1分钟", "minute", 1) == "1分钟后"
+        assert self.locale._format_relative("2分钟", "minutes", 2) == "2分钟后"
+        assert self.locale._format_relative("1小时", "hour", 1) == "1小时后"
+        assert self.locale._format_relative("2小时", "hours", 2) == "2小时后"
+        assert self.locale._format_relative("1天", "day", 1) == "明天"
+        assert self.locale._format_relative("2天", "days", 2) == "后天"
+        assert self.locale._format_relative("3天", "days", 3) == "3天后"
+        assert self.locale._format_relative("1周", "week", 1) == "1周后"
+        assert self.locale._format_relative("2周", "weeks", 2) == "2周后"
+        assert self.locale._format_relative("1个月", "month", 1) == "1个月后"
+        assert self.locale._format_relative("2个月", "months", 2) == "2个月后"
+        assert self.locale._format_relative("1年", "year", 1) == "明年"
+        assert self.locale._format_relative("2年", "years", 2) == "后年"
+        assert self.locale._format_relative("3年", "years", 3) == "3年后"
+
+        assert self.locale._format_relative("1秒", "second", -1) == "1秒前"
+        assert self.locale._format_relative("2秒", "seconds", -2) == "2秒前"
+        assert self.locale._format_relative("1分钟", "minute", -1) == "1分钟前"
+        assert self.locale._format_relative("2分钟", "minutes", -2) == "2分钟前"
+        assert self.locale._format_relative("1小时", "hour", -1) == "1小时前"
+        assert self.locale._format_relative("2小时", "hours", -2) == "2小时前"
+        assert self.locale._format_relative("1天", "day", -1) == "昨天"
+        assert self.locale._format_relative("2天", "days", -2) == "前天"
+        assert self.locale._format_relative("3天", "days", -3) == "3天前"
+        assert self.locale._format_relative("1周", "week", -1) == "1周前"
+        assert self.locale._format_relative("2周", "weeks", -2) == "2周前"
+        assert self.locale._format_relative("1个月", "month", -1) == "1个月前"
+        assert self.locale._format_relative("2个月", "months", -2) == "2个月前"
+        assert self.locale._format_relative("1年", "year", -1) == "去年"
+        assert self.locale._format_relative("2年", "years", -2) == "前年"
+        assert self.locale._format_relative("3年", "years", -3) == "3年前"
+
 
 @pytest.mark.usefixtures("lang_locale")
 class TestSwahiliLocale: