From 57e9d59ec7396f5545e2f0e2ebfc608b48470a4c Mon Sep 17 00:00:00 2001
From: Andrew Cupps <91998663+atcupps@users.noreply.github.com>
Date: Tue, 8 Aug 2023 18:53:26 -0700
Subject: [PATCH] Resolve follow-up comments to #3760 (#3818)

* Docs for `U` and `r`

* Delete empty test and add todo

* Remove old code and empty era check

* Add todo
---
 components/datetime/src/fields/symbols.rs               | 4 ++--
 components/datetime/src/format/datetime.rs              | 5 +----
 components/datetime/src/provider/date_time.rs           | 3 ---
 provider/datagen/src/transform/cldr/datetime/mod.rs     | 1 -
 provider/datagen/src/transform/cldr/datetime/symbols.rs | 2 +-
 5 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/components/datetime/src/fields/symbols.rs b/components/datetime/src/fields/symbols.rs
index b505e59622c..c1f59058f13 100644
--- a/components/datetime/src/fields/symbols.rs
+++ b/components/datetime/src/fields/symbols.rs
@@ -448,9 +448,9 @@ field_type! (
         ///
         /// This works for “week of year” based calendars in which the year transition occurs on a week boundary; may differ from calendar year [`Year::Calendar`] near a year transition. This numeric year designation is used in conjunction with [`Week::WeekOfYear`], but can be used in non-Gregorian based calendar systems where week date processing is desired. The field length is interpreted in the same way as for [`Year::Calendar`].
         'Y' => WeekOf = 1,
-        /// TODO: Docs
+        /// Field symbol for cyclic year; used in calendars where years are tracked in cycles, such as the Chinese or Dangi calendars.
         'U' => Cyclic = 2,
-        /// TODO: Docs
+        /// Field symbol for related ISO; some calendars which use different year numbering than ISO, or no year numbering, may express years in an ISO year corresponding to a calendar year.
         'r' => RelatedIso = 3,
     };
     Numeric;
diff --git a/components/datetime/src/format/datetime.rs b/components/datetime/src/format/datetime.rs
index 94b706cf19e..ec3fe9fddbb 100644
--- a/components/datetime/src/format/datetime.rs
+++ b/components/datetime/src/format/datetime.rs
@@ -300,7 +300,7 @@ where
                         .ok_or(Error::MissingDateSymbols)?
                         .get_symbols_for_month(month, length)?;
                     w.write_str(symbols.get(code).ok_or(Error::MissingMonthSymbol(code))?)?;
-                    w.write_str("(leap)")?;
+                    w.write_str("(leap)")?; // This is temporary; TODO(#3766) add support for leap months
                 }
             }
         },
@@ -640,7 +640,4 @@ mod tests {
             }
         }
     }
-
-    #[test]
-    fn test_year_formatting() {}
 }
diff --git a/components/datetime/src/provider/date_time.rs b/components/datetime/src/provider/date_time.rs
index 707d28d7c55..f05e521c150 100644
--- a/components/datetime/src/provider/date_time.rs
+++ b/components/datetime/src/provider/date_time.rs
@@ -406,9 +406,6 @@ impl<'data> DateSymbols<'data> for provider::calendar::DateSymbolsV1<'data> {
             fields::FieldLength::Narrow => &self.eras.narrow,
             _ => &self.eras.abbr,
         };
-        if symbols.is_empty() {
-            return ""; // If symbols is empty, this calendar doesn't use eras (ex. Chinese)
-        }
         symbols
             .get(era_code.0.as_str().into())
             .unwrap_or(&era_code.0)
diff --git a/provider/datagen/src/transform/cldr/datetime/mod.rs b/provider/datagen/src/transform/cldr/datetime/mod.rs
index ff382531af2..56373a2a576 100644
--- a/provider/datagen/src/transform/cldr/datetime/mod.rs
+++ b/provider/datagen/src/transform/cldr/datetime/mod.rs
@@ -103,7 +103,6 @@ macro_rules! impl_data_provider {
 
                     let mundi_name = ethioaa_data
                         .eras
-                       // .ok_or_else(|| DataError::custom("Could not find eras"))?
                         .names
                         .get("0")
                         .expect("ethiopic-amete-alem calendar must have 0 era");
diff --git a/provider/datagen/src/transform/cldr/datetime/symbols.rs b/provider/datagen/src/transform/cldr/datetime/symbols.rs
index a47003e83bf..9af017450e4 100644
--- a/provider/datagen/src/transform/cldr/datetime/symbols.rs
+++ b/provider/datagen/src/transform/cldr/datetime/symbols.rs
@@ -64,7 +64,7 @@ fn get_month_code_map(calendar: &str) -> &'static [TinyStr4] {
         "gregory" | "buddhist" | "japanese" | "japanext" | "indian" | "persian" | "roc" => {
             &SOLAR_MONTH_CODES[0..12]
         }
-        "coptic" | "ethiopic" | "chinese" => SOLAR_MONTH_CODES,
+        "coptic" | "ethiopic" | "chinese" => SOLAR_MONTH_CODES, // TODO(#3766): Fix leap month formatting
         _ => panic!("Month map unknown for {calendar}"),
     }
 }